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1
Muchlis, Andre, Wrastawa Ridwan, and Iskandar Zulkarnain Nasibu. "Rancang Bangun Mesin CNC (Computer Numerical Control) Laser dengan Metode Design for Assembly." Jambura Journal of Electrical and Electronics Engineering 3, no. 1 (January 9, 2021): 23–27. http://dx.doi.org/10.37905/jjeee.v3i1.9228.
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CNC Laser (Computer Numerical Control) adalah alat yang memiliki fungsi untuk mengukir/mencetak berbagai tulisan dan kaliqrafi secara otomatis berdasarkan media yang digunakan seperti Acrilic, Fiber, Almunium, dan kayu. Perancangan CNC laser menggunakan metode Design For Assembly Boothroyd (DFA), G-Code, dan Closed Loop System (Loop Tertutup). Kelebihan metode DFA yaitu mengestimasikan pengurangan waktu perakitan. Metode G-Code lebih ke menyatukan gerakan yang akan di lakukan mesin, seperti bergeser ke titik A, titik B. Kemudian pada metode Closed Loop System (Loop Tertutup) bekerja mengirim sinyal umpan balik ke pengendali untuk mengecilkan kesalahan sistem. Hasil pengujian dari komponen pada masing-masing alat secara keseluruhan berupa input dan output menjadi kesatuan alat mesin CNC laser cutting dan engraver. Software GRBL dihubungkan pada CNC shild. GRBL mengirim G-Code ke arduino dan menerjemahkan isi dari G-Code satu persatu untuk menghasilkan pergerakan motor stepper dan cahaya laser. Telah didapatkan sistem pengontrolan mesin laser engravir yang bisa menggerakkan mesin kearah dua sumbu X dan Y, yang tersusun dari beberapa komponen yaitu komputer, kontroler arduino nano, motor stepper, laser module, power supplay dan emergency stop. Pengujian laser engraver dilakukan dengan medium plywood dan berbagai pola gambar. Hasil pengujian menunjukkan alat dapat bekerja sesuai dengan pola gambar yang ada.CNC Laser (Computer Numerical Control) tools that have a function to automatically engrave / print various writings and kaliqrafi based on the media used such as Acrilic, Fiber, Aluminum, and wood. CNC laser design uses the Design For Assembly Boothroyd (DFA), G-Code, and Closed Loop System (Closed Loop) method. The advantage of the DFA method is that it estimates the reduced assembly time. The G-Code method is more about unifying the movements that the machine will do, such as moving from point A to point B. Then the Closed Loop System method works to send a feedback signal to the controller to minimize system errors. The test results of the components on each tool as a whole are in the form of input and output into a unity of the CNC laser cutting and engraver machine tool. GRBL software is linked to the CNC shild. The GRBL sends the G-Code to the Arduino and translates the contents of the G-Code one by one to produce stepper motor movement and laser light. A schematic of a laser engraving machine control system that is able to move the machine towards two axes X and Y, which is composed of several components, namely a computer, Arduino nano controller, stepper motor, laser module, power supply and emergency stop. Laser engraver testing was carried out using plywood and various image patterns. The test results show that the tool can work in accordance with existing image patterns.
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Sopandi, Wahyu, Didi Sukyadi, and Rendi Restiana Sukardi. "The Implementation of Guided Research - Based Learning with Graduate School Students of an Elementary Education Study Program." Pedagogika 134, no. 2 (October 18, 2019): 82–98. http://dx.doi.org/10.15823/p.2019.134.5.
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The research aims to investigate how guided research-based learning (GRBL) helps students of an Elementary Education Study Program (EESP) in carrying out research and preparing scientific articles, besides mastering the fundamental concepts of science. This is an experimental one-shot case study research design, which involved seven master’s degree students from our EESP. The result shows that students’ capability is improved, but they still face difficulties in every step of writing publishable scientific articles.
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de VET, Edwin C. J. M., Begoña AGUADO, and R. Duncan CAMPBELL. "Adaptor signalling proteins Grb2 and Grb7 are recruited by human G6f, a novel member of the immunoglobulin superfamily encoded in the MHC." Biochemical Journal 375, no. 1 (October 1, 2003): 207–13. http://dx.doi.org/10.1042/bj20030293.
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The human G6f protein, which is encoded by a gene in the MHC, is a putative cell-surface receptor belonging to the immunoglobulin superfamily. The intracellular tail of G6f is 40 amino acids in length and contains one tyrosine residue (Y281), which is phosphorylated after treatment of cells with pervanadate. This tyrosine residue is found in a consensus-binding motif (YXN) for the Src homology 2 domains of Grb2 and Grb7 (where Grb stands for growth-factor-receptor-bound protein). Glutathione S-transferase pull-down assays showed that the interaction of G6f with both Grb2 and Grb7 is mediated through the Src homology 2 domains of these two proteins and is dependent on the phosphorylation of G6f. Immunoprecipitation experiments showed the interaction of full-length phosphorylated G6f with both full-length Grb2 and Grb7. Antibody cross-linking of G6f expressed in K562 cells resulted in a transient phosphorylation of p42/44 MAP kinase (also known as extracellular-signal-regulated protein kinase-1/2; MAP stands for mitogen-activated protein) which could be prevented by MAP kinase kinase (MEK) inhibitors. These results suggest a coupling of G6f with downstream signal transduction pathways involving Grb2 and Grb7, including the Ras–MAP kinase pathway.
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Praminasari, Reski. "Perancangan Pen Plotter Tiga Sumbu Berbasis Mikrokontroller Arduino." Jurnal Teknologi Elekterika 15, no. 2 (November 30, 2018): 35. http://dx.doi.org/10.31963/elekterika.v15i2.1496.
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Perancangan Pen Plotter Tiga Sumbu Berbasis Mikrokontroller Arduino bertujuan untuk merancang alat pencetak jalur rangkaian elektronika yang praktis dan efisien. Alat ini bekerja dengan menampilkan gambar pada meja kerja sesuai dengan kode yang diterima oleh arduino yang disebut G-Code, yang sebelumnya berbentuk atau berekstensi file gambar dari aplikasi Inkscape dan dikonversi oleh aplikasi Makercam kemudian di unggah oleh aplikasi Xloader serta pergerakannya dikontrol oleh Grbl Controller. Dari hasil pengujian Pen Plotter ini, maka disimpulkan bahwa alat ini dapat mencetak jalur rangkaian elektronika sederhana dan gambar yang beragam melalui aplikasi Inkscape dan Makercam.
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Jufrizaldy, Muhammad, Ilyas Ilyas, and Marzuki Marzuki. "RANCANG BANGUN MESIN CNC MILLING MENGGUNAKAN SYSTEM KONTROL GRBL UNTUK PEMBUATAN LAYOUT PCB." Jurnal Mesin Sains Terapan 4, no. 1 (February 28, 2020): 37. http://dx.doi.org/10.30811/jmst.v4i1.1743.
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Mesin CNC milling adalah mesin potong berbasis komputer yang dapat menjalankan proses secara otomatis pada berbagai macam perintah berbasis bahan yang telah diprogram ke dalam perangkat lunak. Pada tugas akhir kali ini akan dirancang dan diimplementasikan CNC (Computer Numerical Control) Router dengan menggunakan Program G-Code dengan menggunakan GBRL Kontroller sebagai pengontrol mesin CNC. Mikrokontroler digunakan untuk menerima G-Code dari PC yang dikirim ke mikrokontroler yang selanjutnya dikontrol menggunakan GBRL kontroller untuk menggerakan motor Stepper. Mesin CNC ini dikendalikan dengan menggunakan software GRBL dimana ketika program dimasukkan kedalam software tersebut, stepper motor, spindle serta mata bor akan bergerak. Perancangan ini menggunakan 3 buah stepper motor dimana setiap stepper motor berfungsi untuk menggerakkan sumbu X, Y dan Z. Spindle digunakan sebagai pengendali mata bor yang berfungsi untuk mengukir layout pada PCB.Kata kunci : Motor Stepper NEMA , Driver Motor Board T, Breakout Board , Power supply , Spindle Kit
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Suwandi, Herwani, and Septian Tri Setianto. "ANALISA SOFTWARE GRBL CONTROLLER UNTUK MESIN MINI CNC PLOTTER 3 - AXIS DENGAN MENGGUNAKAN MIKRO KONTROLER ATMEGA 328." TEKNOKOM 2, no. 1 (March 26, 2019): 57–64. http://dx.doi.org/10.31943/teknokom.v2i1.17.
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Dalam sebuah industri khususnya manufaktur terdapat mesin CNC dengan berbagai macam jenis sepertiMilling, Frais, Bubut dan banyak lagi yang berfungsi untuk membuat suatu bahan mentah dari besi yang diukir menjadi suatu barang yang berguna bagi kebutuhan manusia, yang biasanya terdiri dari 2 hingga 6 axis.Penulis membuat prototype mesin mini CNC plotter 3 - axis dari bahan standar dengan software yangopensource sehingga seluruh masyarakat bisa mencoba mempelajari mesin CNC tersebut, adapun softwareyang akan digunakan sebagai kontrol dari mesin mini CNC plotter tersebut adalah GRBL Controller danjuga mesin ini menggabungkan software aplikasi inscape yang berguna sebagai converter menjadi GCode.Dalam penulisan penelitian ini metode penelitian yang digunakan penulis yaitu dengan melakukanmetode kuantitatif yang akan menjelaskan sistem dari software mesin mini CNC plotter 3 - axis sehinggamenjadi satu kesatuan sistem yang akan dijelaskan dari data - data G-Code yang sudah dibuat.
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Law, Che-Leung, Maria K. Ewings, Preet M. Chaudhary, Sasha A. Solow, Theodore J. Yun, Aaron J. Marshall, Leroy Hood, and Edward A. Clark. "GrpL, a Grb2-related Adaptor Protein, Interacts with SLP-76 to Regulate Nuclear Factor of Activated T Cell Activation." Journal of Experimental Medicine 189, no. 8 (April 19, 1999): 1243–53. http://dx.doi.org/10.1084/jem.189.8.1243.
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Propagation of signals from the T cell antigen receptor (TCR) involves a number of adaptor molecules. SH2 domain–containing protein 76 (SLP-76) interacts with the guanine nucleotide exchange factor Vav to activate the nuclear factor of activated cells (NF-AT), and its expression is required for normal T cell development. We report the cloning and characterization of a novel Grb2-like adaptor molecule designated as Grb2-related protein of the lymphoid system (GrpL). Expression of GrpL is restricted to hematopoietic tissues, and it is distinguished from Grb2 by having a proline-rich region. GrpL can be coimmunoprecipitated with SLP-76 but not with Sos1 or Sos2 from Jurkat cell lysates. In contrast, Grb2 can be coimmunoprecipitated with Sos1 and Sos2 but not with SLP-76. Moreover, tyrosine-phosphorylated LAT/pp36/38 in detergent lysates prepared from anti-CD3 stimulated T cells associated with Grb2 but not GrpL. These data reveal the presence of distinct complexes involving GrpL and Grb2 in T cells. A functional role of the GrpL–SLP-76 complex is suggested by the ability of GrpL to act alone or in concert with SLP-76 to augment NF-AT activation in Jurkat T cells.
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Bohm, Andrew. "AMi: a GUI-based, open-source system for imaging samples in multi-well plates." Acta Crystallographica Section F Structural Biology Communications 75, no. 8 (August 1, 2019): 531–36. http://dx.doi.org/10.1107/s2053230x19009853.
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Described here are instructions for building and using an inexpensive automated microscope (AMi) that has been specifically designed for viewing and imaging the contents of multi-well plates. The X, Y, Z translation stage is controlled through dedicated software (AMiGUI) that is being made freely available. Movements are controlled by an Arduino-based board running grbl, and the graphical user interface and image acquisition are controlled via a Raspberry Pi microcomputer running Python. Images can be written to the Raspberry Pi or to a remote disk. Plates with multiple sample wells at each row/column position are supported, and a script file for automated z-stack depth-of-field enhancement is written along with the images. The graphical user interface and real-time imaging also make it easy to manually inspect and capture images of individual samples.
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Santoso, Andhik Budi, Didik Riyanto, and Gus Nanang Syaifuddin. "Rancang Bangun Alat Batik Kulit Kepala Harimau Barongan Reyog Ponorogo Menggunakan Arduino." TELKA - Telekomunikasi Elektronika Komputasi dan Kontrol 7, no. 1 (May 24, 2021): 11–20. http://dx.doi.org/10.15575/telka.v7n1.11-20.
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Ponorogo identik dengan kesenian dan kerajinan reyog, salah satunya adalah topeng Barongan. Material utama topeng Barongan adalah kayu dadap sebagai kerangka utama dan kulit harimau sebagai pelapis luarnya. Perburuan harimau dilarang keras dalam rangka konservasi satwa langka, sehingga memaksa pengrajin topeng Barongan mencari alternatif lain, salah satunya menggunakan kulit sapi yang diberi pola khas harimau. Namun teknik yang digunakan masih manual sehingga memerlukan ketelitian, ketekunan dan waktu yang relatif lama. Maka dalam penelitian ini dibuat alat batik kulit kepala harimau Barongan Reyog Ponorogo. Gerakan alat batik kulit Barongan diatur oleh G-Code dan diinput melalui Software Grbl sender. Arduino berfungsi sebagai kontroler yang selanjutnya dapat menggerakkan motor Stepper sebagai penggerak sumbu dan Solenoid sebagai penekan penbrush untuk pewarnaan. Hasil penelitian ini menunjukkan alat batik Barongan Reyog Ponorogo mampu membuat pola harimau pada ukuran 30 x 35 cm dan memiliki kualitas yang hampir sama dengan teknik manual dengan waktu pewarnaan 8 menit. Ponorogo has been famous for its Reyog arts and crafts, one of them is the Barongan mask. The main materials for the Barongan mask are Dadap wood as the mainframe and tiger leather as the outer coating. Tiger hunting is strictly prohibited in the context of the conservation of endangered species. To force the Barongan mask craftsmen for other alternatives, one of the alternatives is to use cow leather which is drawn with a typical tiger pattern. However, the technique used is still manual, meanwhile, the manual technique requires a lot of precision, persistence, and time. So the research aim is to design and implement the tool for drawing the Barongan tiger's scalp on Reyog Ponorogo. The movement of the Barongan leather batik tool was regulated by G-Code and input via the Grbl sender Software then accepted by Arduino as a controller which can then move the Stepper motor as an axis drive and the Solenoid as a pen brush press for coloring. The results of this study indicate that the Barongan Reyog Ponorogo batik tool can make a tiger pattern at a size of 30 x 35 cm and almost has the same quality as the manual technique with a coloring time of 8 minutes.
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MichałowskI, Michał J., Dong Xu, Jamie Stevens, Andrew Levan, Jun Yang, Zsolt Paragi, Atish Kamble, et al. "The second-closest gamma-ray burst: sub-luminous GRB 111005A with no supernova in a super-solar metallicity environment." Astronomy & Astrophysics 616 (August 2018): A169. http://dx.doi.org/10.1051/0004-6361/201629942.
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We report the detection of the radio afterglow of a long gamma-ray burst (GRB) 111005A at 5-345 GHz, including very long baseline interferometry observations with a positional error of 0.2 mas. The afterglow position is coincident with the disc of a galaxy ESO 58049 at z = 0.01326 (∼1″ from its centre), which makes GRB 111005A the second-closest GRB known to date, after GRB 980425. The radio afterglow of GRB 111005A was an order of magnitude less luminous than those of local low-luminosity GRBs, and obviously less luminous than those of cosmological GRBs. The radio flux was approximately constant and then experienced an unusually rapid decay a month after the GRB explosion. Similarly to only two other GRBs, we did not find the associated supernovae (SNe), despite deep near- and mid-infrared observations 1-9 days after the GRB explosion, reaching ∼20 times fainter than other SNe associated with GRBs. Moreover, we measured a twice-solar metallicity for the GRB location. The low y-ray and radio luminosities, rapid decay, lack of a SN, and super-solar metallicity suggest that GRB 111005A represents a rare class of GRB that is different from typical core-collapse events. We modelled the spectral energy distribution of the GRB 111005A host finding that it is a moderately star-forming dwarf galaxy, similar to the host of GRB 980425. The existence of two local GRBs in such galaxies is still consistent with the hypothesis that the GRB rate is proportional to the cosmic star formation rate (SFR) density, but suggests that the GRB rate is biased towards low SFRs. Using the far-infrared detection of ESO 580-49, we conclude that the hosts of both GRBs 111005A and 980425 exhibit lower dust content than what would be expected from their stellar masses and optical colors.
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ARKHANGELSKAJA, IRENE V. "THE CHARACTERISTICS OF GRBs WITH PRESENCE OF HIGH ENERGY COMPONENT IN THEIR SPECTRA." International Journal of Modern Physics: Conference Series 12 (January 2012): 237–46. http://dx.doi.org/10.1142/s2010194512006435.
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The properties of GRBs with presence of high energy emission in spectra are discussed. The temporal profiles of part of events are similar in various energy bands in prompt phase (as for GRB 080528, GRB 021008) but during some events extended high energy emission was detected (for example, GRB 090902B). For other part of GRBs temporal profiles are quite different in various energy bands during prompt phase (as for GRB 050525B), but for some such events extended high energy emission was observed too – for example, GRB 080514B. Moreover, high energy precursors were registered for several GRBs: some photons in energy band 30 MeV - 30 GeV were detected by AGILE during GRB 080514B. The shape of energy spectra of GRBs with presence of high energy emission can follows the Band model (or power law or broken power law) up to some tens or hundreds of MeV (as for GRB 021008) or contains additional high energy power law component (for example, GRB 050525B and GRB 090902B). Following this criteria it is possible to separate two main subclasses of GRBs with high energy emission. Both types of GRBs observed since CGRO mission beginning. The analysis of their energy spectra has shown that the break between additional high energy component and Band (or power law or broken power law) component was in energy region 2-200 MeV. Both types can have got extended high energy emission including component with E > 500 MeV for some events and low energy precursors. The special features of second class of GRBs by the results of preliminary data analysis are the absence of hard to soft evolution in the low energy band and (or) presence of the high energy precursors for some events.
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Corre, D., V. Buat, S. Basa, S. Boissier, J. Japelj, J. Palmerio, R. Salvaterra, S. D. Vergani, and T. Zafar. "Investigation of dust attenuation and star formation activity in galaxies hosting GRBs." Astronomy & Astrophysics 617 (September 2018): A141. http://dx.doi.org/10.1051/0004-6361/201832926.
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Context. The gamma-ray bursts hosts (GRBHs) are excellent targets to study the extinction properties of dust and its effects on the global emission of distant galaxies. The dust extinction curve is measured along the GRB afterglow line of sight and the analysis of the spectral energy distribution (SED) of the host galaxy gives access to the global dust attenuation of the stellar light. Aims. In this pilot study we gather information on dust extinction in GRBHs to compare the properties of the extinction curve to those of the dust obscuration affecting the total stellar light of the host galaxy. Assuming the extinction curve to be representative of the dust properties, we aim to investigate which dust-stars geometries and local dust distribution in the inter stellar medium (ISM) can reproduce the observed attenuation curve. Methods. We selected a sample of 30 GRBs for which the extinction curve along the GRB afterglow line-of-sight (l.o.s.) is measured in the rest-frame ultraviolet (UV) up to optical and we analysed the properties of the extinction curve as a function of the host galaxy properties. From these 30 GRBs, we selected seven GRBHs with a good rest-frame UV to near-infrared (NIR) spectral coverage for the host. The attenuation curve was derived by fitting the SEDs of the GRBH sample with the CIGALE SED fitting code. Different star formation histories (SFH) were studied to recover the star formation rates (SFR) derived using Hα luminosities. Implications for the dust-stars geometries in the ISM are inferred by a comparison with radiative transfer simulations. Results. The most extinguished GRBs are preferentially found in the more massive hosts and the UV bump is preferentially found in the most extinguished GRB l.o.s. Five out of seven hosts are best fitted with a recent burst of star formation, leading to lower stellar mass estimates than previously found. The average attenuation in the host galaxies is about 70% of the amount of extinction along the GRB l.o.s. We find a great variety in the derived attenuation curves of GRBHs, the UV slope can be similar, flatter or even steeper than the extinction curve slope. Half of the attenuation curves are consistent with the Calzetti attenuation law and there is evidence of a UV bump in only one GRBH. We find that the flatter (steeper) attenuation curves are found in galaxies with the highest (lowest) SFR and stellar masses. The comparison of our results with radiative transfer simulations leads to a uniform distribution of dust and stars in a very clumpy ISM for half the GRBHs and various dust-stars geometries for the second half of the sample.
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Quirola, Jonathan, and Nicolás Vásquez. "Study of pulse structure and radiative mechanisms associations of long GRBs atz~1." Proceedings of the International Astronomical Union 10, S313 (September 2014): 394–95. http://dx.doi.org/10.1017/s1743921315002598.
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AbstractIn this work, we have studied five different GRBs detected bySwift: GRB 071010B (z= 0.94), GRB 080411 (z= 1.03), GRB 080413B (z= 1.10), GRB 091208B (z= 1.06) and GRB 110715A (z= 0.82); Those GRBs, with similarzand have well defined pulses. To obtain spectral lag, we fit the light curves with a model having exponential rise and decay parts. In addition, we performed spectral analysis using three spectral models for different GRBs' regions:power law,cutoff power lawandband model. Additionaly, we releated spectral parameters such as photon index and luminosity with spectral lag. The analysis suggests that there are two types of pulses associated to specific radiation mechanisms which would reveal the radiation process of long gamma-ray bursts.
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de Ugarte Postigo, Antonio, Christina Thöne, Zach Cano, David Alexander Kann, Luca Izzo, Rubén Sánchez Ramírez, Katarzyna Bensch, and Ana Sagues. "The diversity of GRBs and their SNe: Observations from the 10.4m GTC." Proceedings of the International Astronomical Union 12, S331 (February 2017): 39–44. http://dx.doi.org/10.1017/s1743921317004860.
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AbstractObserving the supernovae (SNe) associated to the different types of gamma-ray bursts (GRBs) is one of the few means to study their progenitors. In the past years, it has become clear that GRB-like events are more heterogeneous than previously thought. There is a marked difference between long GRBs, which are produced by the collapse of very massive stars and are normally associated with broad-lined type Ic SNe, and short bursts, which occur when two compact objects merge and that, at least in some cases, can produce an associated kilonova. Moreover, the SNe associated with different sub-types of long GRBs are also seen to differ, especially those associated with ultra-long duration GRBs. To address this issue in a systematic way we started an observing programme in 2010 at the 10.4m GTC telescope. Here we present some results of our programme, including the detection of 12 new GRB-SNe. Highlights of our sample are the discovery of the first spectroscopic SN associated with a highly energetic (Eγ, iso ~ 1054 erg) “cosmological” burst (GRB 130427A), the study of the SN associated with a shock-breakout GRB (GRB 140606B) and the SN associated with the peculiar ultra-long GRB 101225A at z = 0.85. The sample includes also the follow-up of several short GRBs in search for kilonovae emission (GRB 130603B and GRB 160821B are important examples). Amongst our latest results we present the photometric and spectroscopic observations of the SNe associated with GRB 150818A and GRB 161219B.
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Totani, Tomonori. "Gamma-Ray Bursts as Cosmological Probes." Proceedings of the International Astronomical Union 7, S279 (April 2011): 241–47. http://dx.doi.org/10.1017/s1743921312012999.
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AbstractThe status and prospects for gamma-ray bursts (GRBs) as cosmological probes are reviewed. Long duration GRBs can potentially be used as an indicator of star formation rate (SFR), though GRB rate might be systematically different from SFR, by the effect of e.g. metallicity. There are several papers claiming that the cosmic GRB rate history is different from that of SFR in the sense that GRB rate is relatively higher than SFR at higher redshifts, which may be explained by the metallicity effect. However, considering the large uncertainties about the efficiency of GRB afterglow detection and redshift determination, it would be conservative to state that the observed GRB rate is roughly consistent with the star formation history. GRBs can also be used as a unique and powerful tool to reveal the reionization history. However, there is practically no progress in this direction since the first GRB-based useful constraint on reionization in 2005 (GRB 050904). The bottleneck now is the insufficient sensitivity of near-infrared spectroscopy, even with 8m class telescopes. The planned 30m class telescopes will bring the next breakthruough. Finally, GRBs can potentially be used as a standard candle to study cosmology by a geometrical test. However, there are still many steps for GRBs to overcome before it produces a result that has strong impact on the cosmology community in the precision cosmology era.
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Tanga, M., T. Krühler, P. Schady, S. Klose, J. F. Graham, J. Greiner, D. A. Kann, and M. Nardini. "The environment of the SN-less GRB 111005A at z = 0.0133." Astronomy & Astrophysics 615 (July 2018): A136. http://dx.doi.org/10.1051/0004-6361/201731799.
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The collapsar model has proved highly successful in explaining the properties of long γ-ray bursts (GRBs), with the most direct confirmation being the detection of a supernova (SN) coincident with the majority of nearby long GRBs. Within this model, a long GRB is produced by the core-collapse of a metal-poor, rapidly rotating, massive star. The detection of some long GRBs in metal-rich environments, and more fundamentally the three examples of long GRBs (GRB 060505, GRB 060614 and GRB 111005A) with no coincident SN detection down to very deep limits is in strong contention with theoretical expectations. In this paper we present MUSE observations of the host galaxy of GRB 111005A, which is the most recent and compelling example yet of a SN-less, long GRB. At z = 0.01326, GRB 111005A is the third closest GRB ever detected, and second closest long duration GRB, enabling the nearby environment to be studied at a resolution of 270 pc. From the analysis of the MUSE data cube, we find GRB 111005A to have occurred within a metal-rich environment with little signs of ongoing star formation. Spectral analysis at the position of the GRB indicates the presence of an old stellar population (τ ≥ 10 Myr), which limits the mass of the GRB progenitor to MZAMS < 15 M⊙, in direct conflict with the collapsar model. Our deep limits on the presence of any SN emission combined with the environmental conditions at the position of GRB 111005A necessitate the exploration of a novel long GRB formation mechanism that is unrelated to massive stars.
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Niino, Yuu. "Revisiting Metallicity of Long Gamma-Ray Burst Host Galaxies: The Role of Chemical Inhomogeneities in Galaxies." Proceedings of the International Astronomical Union 7, S279 (April 2011): 369–70. http://dx.doi.org/10.1017/s1743921312013397.
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AbstractSome theoretical studies on the origin of long gamma-ray bursts (GRBs) using stellar evolution models suggest that a low metallicity environment may be a necessary condition for a GRB to occur. However, recent discoveries of high-metallicity host galaxies of some GRBs cast doubt on the requirement of low-metallicity in GRB occurrence. In this study, we predict the metallicity distribution of GRB host galaxies, assuming empirical formulations of galaxy properties. We take internal dispersion of metallicity within each galaxy into account. Assuming GRBs trace low-metallicity star formation 12+log(O/H) < 8.2, we find that ≳ 10% of GRB host galaxies may have Z > Z⊙, depending on the internal dispersion of metallicity within galaxies.
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Zhang, Hai-Ming, Da-Bin Lin, Ting-Ting Lin, Bao-Rong Liu, Xiao-Li Huang, Shu-Qing Zhong, Rui-Jing Lu, and En-Wei Liang. "Lorentz Factor Evolution Patterns within Relativistic Jets of GRBs and AGNs." Proceedings of the International Astronomical Union 12, S324 (September 2016): 78–81. http://dx.doi.org/10.1017/s1743921317001260.
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AbstractThe Lorentz factor (Γ) is an important parameter related to the relativistic jet physics. We study the evolution patterns of Γ within gamma-ray burst (GRB) and active galactic nuclear jets for individual GRB 090168, GRB 140508A, and 3C 454.3. By estimating the Γ values for well-separated pulses in GRBs 090618 and 140508A with an empirical relation derived from typical GRBs, we find that the Γ evolution pattern in the two GRBs are different. The increasing-to-coasting evolution pattern of Γ in GRB 090618 likely indicates that the GRB fireball is still being accelerated in the prompt phase. The clear decrease evolution pattern of Γ in GRB 140508A suggests the deceleration of the fireball components. By deriving the Γ value through fitting their spectral energy distribution in different flares of 3C 454.3, a pattern of Γ-tracking-γ-ray flux is clearly found, likely indicating that the observed gamma-ray flares are being due to the Doppler boosting effect to the jet emission.
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Luzy, Jean-Philippe, Huixiong Chen, Brunilde Gril, Wang-Qing Liu, Michel Vidal, Dominique Perdereau, Anne-Françoise Burnol, and Christiane Garbay. "Development of Binding Assays for the SH2 Domain of Grb7 and Grb2 Using Fluorescence Polarization." Journal of Biomolecular Screening 13, no. 2 (January 23, 2008): 112–19. http://dx.doi.org/10.1177/1087057107312124.
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Adaptor proteins Grb7 and Grb2 have been implicated as being 2 potential therapeutic targets in several human cancers, especially those that overexpress ErbB2. These 2 proteins contain both a SH2 domain (Src homology 2) that binds to phosphorylated tyrosine residues contained within ErbB2 and other specific protein targets. Two assays based on enzyme-linked immunosorbent assay and fluorescence polarization methods have been developed and validated to find and rank inhibitors for both proteins binding to the pY1139. Fluorescence polarization assays allowed the authors to determine quickly and reproducibly affinities of peptides from low nanomolar to high micromolar range and to compare them directly for Grb7 and Grb2. As a result, the assays have identified a known peptidomimetic Grb2 SH2 inhibitor (mAZ-pTyr-(αMe)pTyr-Asn-NH2) that exhibits the most potent affinity for the Grb7 SH2 domain described to date. ( Journal of Biomolecular Screening 2008:112-119)
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Zhang, Bing. "GRB Progenitors and Observational Criteria." Proceedings of the International Astronomical Union 7, S279 (April 2011): 102–9. http://dx.doi.org/10.1017/s1743921312012768.
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AbstractPhenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their γ-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB progenitors: one related to massive stars (Type II), and another related to compact stars (Type I). Evidence suggests that the majority of long GRBs belong to Type II, while at least the majority of nearby short GRBs belong to Type I. Nonetheless, counter examples do exist. Both long-duration Type I and short-duration Type II GRBs have been observed. In this talk, I review the complications in GRB classification and efforts in diagnosing GRB progenitors based on multiple observational criteria. In particular, I raise the caution to readily accept that all short/hard GRBs detected by BATSE are due to compact star mergers. Finally, I propose to introduce “amplitude” as the third dimension (besides “duration” and “hardness”) to quantify burst properties, and point out that the “tip-of-the-iceberg” effect may introduce confusion in defining the physical category of GRBs, especially for low-amplitude, high-redshift GRBs.
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Lloyd-Ronning, Nicole M., Jarrett L. Johnson, and Aycin Aykutalp. "The consequences of gamma-ray burst jet opening angle evolution on the inferred star formation rate." Monthly Notices of the Royal Astronomical Society 498, no. 4 (September 12, 2020): 5041–47. http://dx.doi.org/10.1093/mnras/staa2787.
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ABSTRACT Gamma-ray burst (GRB) data suggest that the jets from GRBs in the high redshift universe are more narrowly collimated than those at lower redshifts. This implies that we detect relatively fewer long GRB progenitor systems (i.e. massive stars) at high redshifts, because a greater fraction of GRBs have their jets pointed away from us. As a result, estimates of the star formation rate (SFR; from the GRB rate) at high redshifts may be diminished if this effect is not taken into account. In this paper, we estimate the SFR using the observed GRB rate, accounting for an evolving jet opening angle. We find that the SFR in the early universe (z > 3) can be up to an order of magnitude higher than the canonical estimates, depending on the severity of beaming angle evolution and the fraction of stars that make long GRBs. Additionally, we find an excess in the SFR at low redshifts, although this lessens when accounting for evolution of the beaming angle. Finally, under the assumption that GRBs do, in fact, trace canonical forms of the cosmic SFR, we constrain the resulting fraction of stars that must produce GRBs, again accounting for jet beaming-angle evolution. We find this assumption suggests a high fraction of stars in the early universe producing GRBs – a result that may, in fact, support our initial assertion that GRBs do not trace canonical estimates of the SFR.
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THÖMMES, Kerstin, Johan LENNARTSSON, Monika CARLBERG, and Lars RÖNNSTRAND. "Identification of Tyr-703 and Tyr-936 as the primary association sites for Grb2 and Grb7 in the c-Kit/stem cell factor receptor." Biochemical Journal 341, no. 1 (June 24, 1999): 211–16. http://dx.doi.org/10.1042/bj3410211.
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In this paper we demonstrate the presence of two novel in vivo autophosphorylation sites in the c-Kit/stem cell factor receptor (c-Kit/SCFR): Tyr-703 in the kinase insert and Tyr-936 in the C-terminal tail. We furthermore demonstrate that the adapter protein Grb2 is a specific binding partner for both phosphorylated Tyr-703 and phosphorylated Tyr-936, whereas the adapter protein Grb7 binds selectively to phosphorylated Tyr-936. It is shown that the association occurs through the Src homology 2 (SH2) domains of Grb2 and Grb7. Binding of Grb2 to Tyr-703 in the c-Kit/SCFR provides a link to the Ras/mitogen-activated protein kinase pathway.
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CUI, XIAO-HONG, ZHUO LI, and LI-PING XIN. "GRB PROMPT OPTICAL/UV EMISSION AND DUST SUBLIMATION." International Journal of Modern Physics: Conference Series 23 (January 2013): 198–201. http://dx.doi.org/10.1142/s2010194513011306.
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Observations imply that long γ-ray bursts (GRBs) are originated from explosions of massive stars, therefore they may occur in the molecular clouds where their progenitors were born. We show here that the prompt optical-UV emission from GRBs may be delayed due to the dust extinction, which can well explain the observed optical delayed onset and fast rise in GRB 080319B. The density and the size of the molecular cloud around GRB 080319B are roughly constrained to be ~ 103cm-3 and ~ 8pc, respectively. We also investigate the other GRBs with prompt optical-UV data, and find similar values of the densities and sizes of the local molecular clouds. The future observations of prompt optical-UV emission from GRBs in subsecond timescale, e.g., by UFFO-Pathfinder and SVOM-GWAC, will provide more evidence and probes of the local GRB environments.
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Maselli, A., A. Melandri, L. Nava, C. G. Mundell, N. Kawai, S. Campana, S. Covino, et al. "GRB 130427A: A Nearby Ordinary Monster." Science 343, no. 6166 (November 21, 2013): 48–51. http://dx.doi.org/10.1126/science.1242279.
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Long-duration gamma-ray bursts (GRBs) are an extremely rare outcome of the collapse of massive stars and are typically found in the distant universe. Because of its intrinsic luminosity (L ∼ 3 × 1053 ergs per second) and its relative proximity (z = 0.34), GRB 130427A reached the highest fluence observed in the γ-ray band. Here, we present a comprehensive multiwavelength view of GRB 130427A with Swift, the 2-meter Liverpool and Faulkes telescopes, and by other ground-based facilities, highlighting the evolution of the burst emission from the prompt to the afterglow phase. The properties of GRB 130427A are similar to those of the most luminous, high-redshift GRBs, suggesting that a common central engine is responsible for producing GRBs in both the contemporary and the early universe and over the full range of GRB isotropic energies.
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Chrimes, A. A., A. J. Levan, E. R. Stanway, J. D. Lyman, A. S. Fruchter, P. Jakobsson, P. O’Brien, et al. "Chandra and Hubble Space Telescope observations of dark gamma-ray bursts and their host galaxies." Monthly Notices of the Royal Astronomical Society 486, no. 3 (April 15, 2019): 3105–17. http://dx.doi.org/10.1093/mnras/stz1039.
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Abstract We present a study of 21 dark gamma-ray burst (GRB) host galaxies, predominantly using X-ray afterglows obtained with the Chandra X-Ray Observatory (CXO) to precisely locate the burst in deep Hubble Space Telescope (HST) imaging of the burst region. The host galaxies are well-detected in F160W in all but one case and in F606W imaging in 60 per cent of cases. We measure magnitudes and perform a morphological analysis of each galaxy. The asymmetry, concentration, and ellipticity of the dark burst hosts are compared against the host galaxies of optically bright GRBs. In agreement with other studies, we find that dark GRB hosts are redder and more luminous than the bulk of the GRB host population. The distribution of projected spatial offsets for dark GRBs from their host galaxy centroids is comparable to that of optically bright bursts. The dark GRB hosts are physically larger, more massive and redder, but are morphologically similar to the hosts of bright GRBs in terms of concentration and asymmetry. Our analysis constrains the fraction of high redshift (z > 5) GRBs in the sample to 14 per cent, implying an upper limit for the whole long-GRB population of ≤4.4 per cent. If dust is the primary cause of afterglow darkening amongst dark GRBs, the measured extinction may require a clumpy dust component in order to explain the observed offset and ellipticity distributions.
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Lan, Lin, Rui-Jingi Lu, Hou-Jun Lü, Jun Shen, Jared Rice, Long Li, and En-Wei Liang. "The properties of prompt emission in short gamma-ray bursts with extended emission observed by Fermi/GBM." Monthly Notices of the Royal Astronomical Society 492, no. 3 (January 25, 2020): 3622–30. http://dx.doi.org/10.1093/mnras/staa044.
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ABSTRACT Short gamma-ray bursts (GRB) with extended emission (EE) that are composed of an initial short hard spike followed by a long-lasting EE are thought to comprise a sucategory of short GRBs. The narrow energy band available during the Swift era, combined with a lack of spectral information, prevented the discovery of the intrinsic properties of these events. In this paper, we perform a systematic search of short GRBs with EE using all available Fermi/GBM data. The search identified 26 GBM-detected short GRBs with EE that are similar to GRB 060614 observed by Swift/BAT. We focus on investigating the spectral and temporal properties of both the hard spike and the EE component of all 26 GRBs, and explore differences and possible correlations between them. We find that while the peak energy (Ep) of the hard spikes is slightly harder than that of the EE, their fluences are comparable. The harder Ep seems to correspond to a larger fluence and peak flux, with a large scatter for both the hard spike and the EE component. Moreover, the Ep of both the hard spike and the EE are compared with other short GRBs. Finally, we also compare the properties of GRB 170817A with those of short GRBs with EE and find no significant statistical differences between them. We find that GRB 170817A has the lowest Ep, probably because it is off-axis.
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Sugiyama, Yoriko, Kiichiro Tomoda, Toshiaki Tanaka, Yukinobu Arata, Noriko Yoneda-Kato, and Jun-ya Kato. "Direct Binding of the Signal-transducing Adaptor Grb2 Facilitates Down-regulation of the Cyclin-dependent Kinase Inhibitor p27Kip1." Journal of Biological Chemistry 276, no. 15 (January 22, 2001): 12084–90. http://dx.doi.org/10.1074/jbc.m010811200.
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Ectopic expression of Jab1/CSN5 induces specific down-regulation of the cyclin-dependent kinase (Cdk) inhibitor p27 (p27Kip1) in a manner dependent upon transportation from the nucleus to the cytoplasm. Here we show that Grb2 and Grb3-3, the molecules functioning as an adaptor in the signal transduction pathway, specifically and directly bind to p27 in the cytoplasm and participate in the regulation of p27. The interaction requires the C-terminal SH3-domain of Grb2/3-3 and the proline-rich sequence contained in p27 immediately downstream of the Cdk binding domain. In living cells, enforcement of the cytoplasmic localization of p27, either by artificial manipulation of the nuclear/cytoplasmic transport signal sequence or by coexpression of ectopic Jab1/CSN5, markedly enhances the stable interaction between p27 and Grb2. Overexpression of Grb2 accelerates Jab1/CSN5-mediated degradation of p27, while Grb3-3 expression suppresses it. A p27 mutant unable to bind to Grb2 is transported into the cytoplasm in cells ectopically expressing Jab1/CSN5 but is refractory to the subsequent degradation. These findings indicate that Grb2 participates in a negative regulation of p27 and may directly link the signal transduction pathway with the cell cycle regulatory machinery.
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Nomoto, K., N. Tominaga, M. Tanaka, K. Maeda, and H. Umeda. "The Connection between Gamma-Ray Bursts and Extremely Metal-Poor Stars as Nucleosynthetic Probes of the Early Universe." Proceedings of the International Astronomical Union 3, S250 (December 2007): 463–70. http://dx.doi.org/10.1017/s1743921308020838.
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AbstractThe connection between the long GRBs and Type Ic Supernovae (SNe) has revealed the interesting diversity: (i) GRB-SNe, (ii) Non-GRB Hypernovae (HNe), (iii) X-Ray Flash (XRF)-SNe, and (iv) Non-SN GRBs (or dark HNe). We show that nucleosynthetic properties found in the above diversity are connected to the variation of the abundance patterns of extremely-metal-poor (EMP) stars, such as the excess of C, Co, Zn relative to Fe. We explain such a connection in a unified manner as nucleosynthesis of hyper-aspherical (jet-induced) explosions of Pop III core-collapse SNe. We show that (1) the explosions with large energy deposition rate, Ėdep, are observed as GRB-HNe and their yields can explain the abundances of normal EMP stars, and (2) the explosions with small Ėdepare observed as GRBs without bright SNe and can be responsible for the formation of the C-rich EMP (CEMP) and the hyper metal-poor (HMP) stars. We thus propose that GRB-HNe and the Non-SN GRBs (dark HNe) belong to a continuous series of BH-forming massive stellar deaths with the relativistic jets of different Ėdep.
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Cobb, Bethany Elisa. "Recent Observations of GRB-Supernovae." Proceedings of the International Astronomical Union 7, S279 (April 2011): 83–90. http://dx.doi.org/10.1017/s1743921312012732.
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AbstractThe GRB-SNe connection has been strengthened since 2008 by the detection of 6 additional GRB-SNe at both local and cosmological redshifts. This review summarizes the recent observations of SNe associated with GRBs 081007, 090618, 091127, 100316D, 101219B and 111211A, as well as the observations of SN 2008D, which was associated with a bright X-ray flash (XRF 080109) and may represent a link between “plain” SN and GRB-SNe. It is now clear that most – if not all – long-duration GRBs are produced by the core collapse of massive stars.
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RUFFINI, REMO. "BLACK HOLES, SUPERNOVAE AND GAMMA RAY BURSTS." International Journal of Modern Physics D 22, no. 11 (September 2013): 1360009. http://dx.doi.org/10.1142/s0218271813600092.
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We review recent progress in our understanding of the nature of Gamma Ray Bursts (GRBs) and in particular, of the relationship between short GRBs and long GRBs. The first example of a short GRB is described. The coincidental occurrence of a GRB with a supernova (SN) is explained within the induced gravitational collapse (IGC) paradigm, following the sequence: (1) an initial binary system consists of a compact carbon–oxygen (CO) core star and a neutron star (NS); (2) the CO core explodes as a SN, and part of the SN ejecta accretes onto the NS which reaches its critical mass and collapses to a black hole (BH) giving rise to a GRB; (3) a new NS is generated by the SN as a remnant. The observational consequences of this scenario are outlined.
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Řípa, Jakub, and Arman Shafieloo. "Update on testing the isotropy of the properties of gamma-ray bursts." Monthly Notices of the Royal Astronomical Society 486, no. 3 (April 26, 2019): 3027–40. http://dx.doi.org/10.1093/mnras/stz921.
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Abstract Previously, we proposed a novel method to inspect the isotropy of the properties of gamma-ray bursts (GRBs), such as their duration, fluences and peak fluxes at various energy bands and different time-scales, complementary to existing studies of the spatial distribution of GRBs by other authors. The method was then applied to the Fermi Gamma-ray Burst Monitor (GBM) Burst Catalog containing 1591 GRBs. Except for one particular direction where we noticed some hints of violation from statistical isotropy, the rest of the data showed consistency with isotropy. In this work, we apply our method, with some minor modifications, to the updated Fermi GBM data sample containing 2266 GRBs, which is thus ∼40 per cent larger. We also test two other major GRB catalogues: the Burst And Transient Source Experiment (BATSE) Current GRB Catalog of the Compton Gamma Ray Observatory (CGRO), containing ∼2000 bursts, and the Swift Burst Alert Telescope (BAT) GRB Catalog, containing ∼1200 bursts. The new results using the updated data are consistent with our previous findings and we find no statistically significant anisotropic feature in the observed properties of these samples of all GRBs.
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Zhang, Bing, Enwei Liang, Nayantara Gupta, Bin-Bin Zhang, Francisco Virgili, and Z. G. Dai. "Messages from GRB 060218." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, no. 1854 (February 9, 2007): 1257–62. http://dx.doi.org/10.1098/rsta.2006.1999.
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GRB 060218 is a watershed event. Statistically, its detection suggests that there is likely a distinct low-luminosity (LL) population of gamma-ray bursts (GRBs) whose event rate is much higher than that of conventional high-luminosity GRBs. This LL population may give significant contribution to the diffuse neutrino background flux at energies higher than 10 16 eV. The spectral lag of this burst is very long, and roughly follows the luminosity–lag relation of normal GRBs. This, along with the fact that it follows the E p – E iso relation as well, suggests that X-ray flashes (XRFs) are natural extension of GRBs in the softer regime and that GRBs and XRFs share the same radiation physics. We discuss how the broadband data pose strong constraints on possible models of the prompt emission of this GRB.
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Cano, Zach, Shan-Qin Wang, Zi-Gao Dai, and Xue-Feng Wu. "The Observer’s Guide to the Gamma-Ray Burst Supernova Connection." Advances in Astronomy 2017 (2017): 1–41. http://dx.doi.org/10.1155/2017/8929054.
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We present a detailed report of the connection between long-duration gamma-ray bursts (GRBs) and their accompanying supernovae (SNe). The discussion presented here places emphasis on how observations, and the modelling of observations, have constrained what we know about GRB-SNe. We discuss their photometric and spectroscopic properties, their role as cosmological probes, including their measured luminosity–decline relationships, and how they can be used to measure the Hubble constant. We present a statistical summary of their bolometric properties and use this to determine the properties of the “average” GRB-SN. We discuss their geometry and consider the various physical processes that are thought to power the luminosity of GRB-SNe and whether differences exist between GRB-SNe and the SNe associated with ultra-long-duration GRBs. We discuss how observations of their environments further constrain the physical properties of their progenitor stars and give a brief overview of the current theoretical paradigms of their central engines. We then present an overview of the radioactively powered transients that have been photometrically associated with short-duration GRBs, and we conclude by discussing what additional research is needed to further our understanding of GRB-SNe, in particular the role of binary-formation channels and the connection of GRB-SNe with superluminous SNe.
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Watson, D., J. P. U. Fynbo, C. C. Thöne, and J. Sollerman. "No supernovae detected in two long-duration gamma-ray bursts." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, no. 1854 (February 12, 2007): 1269–75. http://dx.doi.org/10.1098/rsta.2006.1994.
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There is strong evidence that long-duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. In the standard version of the collapsar model, a broad-lined and luminous Type Ic core-collapse supernova (SN) accompanies the GRB. This association has been confirmed in observations of several nearby GRBs. Recent observations show that some long-duration GRBs are different. No SN emission accompanied the long-duration GRBs 060505 and 060614 down to limits fainter than any known Type Ic SN and hundreds of times fainter than the archetypal SN 1998bw that accompanied GRB 980425. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration. Furthermore, the bursts originated in star-forming galaxies, and in the case of GRB 060505, the burst was localized to a compact star-forming knot in a spiral arm of its host galaxy. We find that the properties of the host galaxies, the long duration of the bursts and, in the case of GRB 060505, the location of the burst within its host, all imply a massive stellar origin. The absence of an SN to such deep limits therefore suggests a new phenomenological type of massive stellar death.
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Mong, Y.-L., K. Ackley, D. K. Galloway, M. Dyer, R. Cutter, M. J. I. Brown, J. Lyman, et al. "Searching for Fermi GRB optical counterparts with the prototype Gravitational-wave Optical Transient Observer (GOTO)." Monthly Notices of the Royal Astronomical Society 507, no. 4 (September 7, 2021): 5463–76. http://dx.doi.org/10.1093/mnras/stab2499.
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ABSTRACT The typical detection rate of ∼1 gamma-ray burst (GRB) per day by the Fermi Gamma-ray Burst Monitor (GBM) provides a valuable opportunity to further our understanding of GRB physics. However, the large uncertainty of the Fermi localization typically prevents rapid identification of multiwavelength counterparts. We report the follow-up of 93 Fermi GRBs with the Gravitational-wave Optical Transient Observer (GOTO) prototype on La Palma. We selected 53 events (based on favourable observing conditions) for detailed analysis, and to demonstrate our strategy of searching for optical counterparts. We apply a filtering process consisting of both automated and manual steps to 60 085 candidates initially, rejecting all but 29, arising from 15 events. With ≈3 GRB afterglows expected to be detectable with GOTO from our sample, most of the candidates are unlikely to be related to the GRBs. Since we did not have multiple observations for those candidates, we cannot confidently confirm the association between the transients and the GRBs. Our results show that GOTO can effectively search for GRB optical counterparts thanks to its large field of view of ≈40 deg2 and its depth of ≈20 mag. We also detail several methods to improve our overall performance for future follow-up programmes of Fermi GRBs.
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Schady, Patricia. "Gamma-ray bursts and their use as cosmic probes." Royal Society Open Science 4, no. 7 (July 2017): 170304. http://dx.doi.org/10.1098/rsos.170304.
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Since the launch of the highly successful and ongoing Swift mission, the field of gamma-ray bursts (GRBs) has undergone a revolution. The arcsecond GRB localizations available within just a few minutes of the GRB alert has signified the continual sampling of the GRB evolution through the prompt to afterglow phases revealing unexpected flaring and plateau phases, the first detection of a kilonova coincident with a short GRB, and the identification of samples of low-luminosity, ultra-long and highly dust-extinguished GRBs. The increased numbers of GRB afterglows, GRB-supernova detections, redshifts and host galaxy associations has greatly improved our understanding of what produces and powers these immense, cosmological explosions. Nevertheless, more high-quality data often also reveal greater complexity. In this review, I summarize some of the milestones made in GRB research during the Swift era, and how previous widely accepted theoretical models have had to adapt to accommodate the new wealth of observational data.
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Joshi, Jagdish C., and Soebur Razzaque. "Modelling synchrotron and synchrotron self-Compton emission of gamma-ray burst afterglows from radio to very-high energies." Monthly Notices of the Royal Astronomical Society 505, no. 2 (May 10, 2021): 1718–29. http://dx.doi.org/10.1093/mnras/stab1329.
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ABSTRACT Synchrotron radiation from a decelerating blastwave is a widely accepted model of radio to X-ray afterglow emission from gamma-ray bursts (GRBs). GeV gamma-ray emission detected by the Fermi Large Area Telescope (LAT) and the duration of which extends beyond the prompt gamma-ray emission phase is also compatible with broad features of afterglow emission. We revisit the synchrotron self-Compton (SSC) emission model from a decelerating blastwave to fit multiwavelength data from three bright GRBs, namely GRB 190114C, GRB 130427A, and GRB 090510. We constrain the afterglow model parameters using the simultaneous fit of the spectral energy distributions at different times and light curves at different frequencies for these bursts. We find that a constant density interstellar medium is favoured for the short GRB 090510, while a wind-type environment is favoured for the long GRB 130427A and GRB 190114C. The sub-TeV component in GRB 190114C detected by MAGIC is the SSC emission in our modelling. Furthermore, we find that the SSC emission in the Thomson regime is adequate to fit the spectra and light curves of GRB 190114C. For the other two GRBs, lacking sub-TeV detection, the SSC emissions are also modelled in the Thomson regime. For the model parameters we have used, the γγ attenuation in the blastwave is negligible in the sub-TeV range compared to the redshift-dependent γγ attenuation in the extragalactic background light.
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Zhang, K., Z. B. Zhang, Y. F. Huang, L. M. Song, S. J. Zheng, X. J. Li, D. Li, and F. F. Su. "How are gamma-ray burst radio afterglows populated?" Monthly Notices of the Royal Astronomical Society 503, no. 3 (February 19, 2021): 3262–78. http://dx.doi.org/10.1093/mnras/stab465.
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ABSTRACT We systematically analyse two GRB samples with radio-loud and radio-quiet afterglows, respectively. It is interestingly found that the radio-selected GRB samples exhibit a clear dichotomy in terms of their distributions of intrinsic durations (Tint), isotropic energies in γ-rays (Eγ, iso), the circum-burst medium density (n), the spectral radio peak luminosity (Lν, p) and flux densities (Fhost) of host galaxies. On average, the values of Tint, Eγ, iso, n, Lν, p, and Fhost of radio-quiet GRBs are relatively smaller than those of radio-loud ones. However, the redshifts and host flux densities of both samples are similarly distributed. In addition, a positive power-law correlation of $L_{\nu ,p}\propto E_{\gamma ,\rm iso}^{0.41\pm 0.04}$ is found for the radio-loud sample, especially in accord with the supernova-associated GRBs, which is marginally consistent with that of the radio-quiet GRB sample. A negative correlation between Tint and z is confirmed to similarly hold for both radio-loud and radio-quiet GRBs. The dividing line between short and long GRBs in the rest frame is at Tint ≃1 s. Consequently, we propose that the radio-selected GRBs could be originated from distinct progenitors and central engines, together with environments.
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Lien, Amy, Takanori Sakamoto, Neil Gehrels, David Palmer, and Carlo Graziani. "Trigger Simulations for GRB Detection with the Swift Burst Alert Telescope." Proceedings of the International Astronomical Union 7, S279 (April 2011): 347–48. http://dx.doi.org/10.1017/s1743921312013282.
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AbstractUnderstanding the intrinsic cosmic long gamma-ray burst (GRB) rate is essential in many aspects of astrophysics and cosmology, such as revealing the connection between GRBs, supernovae (SNe), and stellar evolution. Swift, a multi-wavelength space telescope, is quickly expanding the GRB category by observing hundreds of GRBs and their redshifts. However, it remains difficult to determine the intrinsic GRB rate due to the complex trigger algorithm adopted by Swift. Current studies of the GRB rate usually approximate the Swift trigger algorithm by a single detection threshold. Nevertheless, unlike the previously flown GRB instruments, Swift has over 500 trigger criteria based on count rates and additional thresholds for localization. To investigate possible systematic biases and further explore the intrinsic GRB rate as a function of redshift and the GRB luminosity function, we adopt a Monte Carlo approach by simulating all trigger criteria used by Swift. A precise estimation of the intrinsic GRB rate is important to reveal the GRB origins and their relation to the black-hole forming SNe. Additionally, the GRB rate at high redshifts provides a strong probe of the star formation history in the early universe, which is hard to measure directly through other methods.
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Melott, A. L., B. S. Lieberman, C. M. Laird, L. D. Martin, M. V. Medvedev, B. C. Thomas, J. K. Cannizzo, N. Gehrels, and C. H. Jackman. "Did a gamma-ray burst initiate the late Ordovician mass extinction?" International Journal of Astrobiology 3, no. 1 (January 2004): 55–61. http://dx.doi.org/10.1017/s1473550404001910.
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Gamma-ray bursts (GRBs) produce a flux of radiation detectable across the observable Universe. A GRB within our own galaxy could do considerable damage to the Earth's biosphere; rate estimates suggest that a dangerously near GRB should occur on average two or more times per billion years. At least five times in the history of life, the Earth has experienced mass extinctions that eliminated a large percentage of the biota. Many possible causes have been documented, and GRBs may also have contributed. The late Ordovician mass extinction approximately 440 million years ago may be at least partly the result of a GRB. A special feature of GRBs in terms of terrestrial effects is a nearly impulsive energy input of the order of 10 s. Due to expected severe depletion of the ozone layer, intense solar ultraviolet radiation would result from a nearby GRB, and some of the patterns of extinction and survivorship at this time may be attributable to elevated levels of UV radiation reaching the Earth. In addition, a GRB could trigger the global cooling which occurs at the end of the Ordovician period that follows an interval of relatively warm climate. Intense rapid cooling and glaciation at that time, previously identified as the probable cause of this mass extinction, may have resulted from a GRB.
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Kann, D. A., P. Schady, E. F. Olivares, S. Klose, A. Rossi, D. A. Perley, B. Zhang, et al. "The optical/NIR afterglow of GRB 111209A: Complex yet not unprecedented." Astronomy & Astrophysics 617 (September 2018): A122. http://dx.doi.org/10.1051/0004-6361/201731292.
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Context. Afterglows of gamma-ray bursts (GRBs) are simple in the most basic model, but can show many complex features. The ultra-long duration GRB 111209A, one of the longest GRBs ever detected, also has the best-monitored afterglow in this rare class of GRBs. Aims. We want to address the question whether GRB 111209A was a special event beyond its extreme duration alone, and whether it is a classical GRB or another kind of high-energy transient. The afterglow may yield significant clues. Methods. We present afterglow photometry obtained in seven bands with the GROND imager as well as in further seven bands with the Ultraviolet/Optical Telescope (UVOT) on-board the Neil Gehrels Swift Observatory. The light curve is analysed by multi-band modelling and joint fitting with power-laws and broken power-laws, and we use the contemporaneous GROND data to study the evolution of the spectral energy distribution. We compare the optical afterglow to a large ensemble we have analysed in earlier works, and especially to that of another ultra-long event, GRB 130925A. We furthermore undertake a photometric study of the host galaxy. Results. We find a strong, chromatic rebrightening event at ≈0.8 days after the GRB, during which the spectral slope becomes redder. After this, the light curve decays achromatically, with evidence for a break at about 9 days after the trigger. The afterglow luminosity is found to not be exceptional. We find that a double-jet model is able to explain the chromatic rebrightening. The afterglow features have been detected in other events and are not unique. Conclusions. The duration aside, the GRB prompt emission and afterglow parameters of GRB 111209A are in agreement with the known distributions for these parameters. While the central engine of this event may differ from that of classical GRBs, there are multiple lines of evidence pointing to GRB 111209A resulting from the core-collapse of a massive star with a stripped envelope.
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LIANG, EN-WEI, HOUJUN LÜ, SHUANG-XI YI, BING ZHANG, BIN-BIN ZHANG, and JIN ZHANG. "DISCERNING EMISSION COMPONENTS IN EARLY AFTERGLOW DATA AND CONSTRAINING THE INITIAL LORENTZ FACTOR OF LONG GRB FIREBALL." International Journal of Modern Physics D 20, no. 10 (September 2011): 1955–59. http://dx.doi.org/10.1142/s0218271811020007.
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We prove that both the canonical and single power-law decay X-ray afterglow lightcurves of gamma-ray bursts (GRBs) observed with the Swift X-ray telescope may be an emission component radiated by external shocks prior to the GRB trigger. Our systematical analysis on both the early optical and X-ray afterglow data also indicates that they might be from different components. The detected optical emission possibly is dominated by the afterglow of the GRB fireball. The X-ray afterglows may be detected for some GRBs, but most of the detected X-rays for most GRBs are likely dominated by the prior X-ray component. With the deceleration feature in the early optical afterglow data, we estimate the initial Lorentz factors of the GRBs and discover a tight relation of the Lorentz factor to the isotropic gamma-ray energy.
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Castro-Tirado, Alberto J. "Gamma-ray Bursts." International Astronomical Union Colloquium 192 (2005): 459–66. http://dx.doi.org/10.1017/s0252921100009544.
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SummarySince their discovery in 1967 Gamma-ray bursts (GRBs) have been puzzling to astrophysicists. With the advent of a new generation of X–ray satellites in the late 90’s, it was possible to carry out deep multi-wavelength observations of the counterparts associated with the long duration GRBs class just within a few hours of occurrence, thanks to the observation of the fading X-ray emission that follows the more energetic gamma-ray photons once the GRB event has ended. The fact that this emission (the afterglow) extends at longer wavelengths, led to the discovery of optical/IR/radio counterparts in 1997-2003, greatly improving our understanding of these sources. The classical, long duration GRBs, have been observed to originate at cosmological distances in a range of redshifts with 0.1685 ≤ z ≤ 4.50 implying energy releases of ~ 1051 ergs. The recent results on GRB 021004 and GRB 030329 confirm that the central engines that power these extraordinary events are due to be collapse of massive stars rather than the merging of compact objects as previously also suggested. Short GRBs still remain a mystery as no counterparts have been detected so far.
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Shibata, R., T. Murakami, Y. Ueda, A. Yoshida, F. Tokanai, C. Otani, N. Kawai, and K. Hurley. "Possible X-Ray Counterparts to Gamma-Ray Bursts, GRB930131 and GRB940217." Symposium - International Astronomical Union 188 (1998): 459–60. http://dx.doi.org/10.1017/s0074180900116018.
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We made a search of quiescent X-ray counterparts of two Gamma-Ray Bursts (GRBs), GRB930131 and GRB940217. These GRBs were detected with BATSE, EGRET, COMPTEL on board CGRO together with the GRB detector on Ulysses spacecraft, then they were localized in small error regions. These observations showed that the bursts were remarkably bright accompanying delayed high energy gamma-rays. ASCA observations have found a single X-ray source for each GRB on the possible location determined with the above instruments.
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Ioka, Kunihito, Yudai Suwa, Hiroki Nagakura, Rafael S. de Souza, and Naoki Yoshida. "Population III Gamma-Ray Burst." Proceedings of the International Astronomical Union 7, S279 (April 2011): 301–4. http://dx.doi.org/10.1017/s1743921312013099.
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AbstractGamma-ray bursts (GRBs) are unique probes of the first generation (Pop III) stars. We show that a relativistic gamma-ray burst (GRB) jet can potentially pierce the envelope of a very massive Pop III star even if the Pop III star has a supergiant hydrogen envelope without mass loss, thanks to the long-lived powerful accretion of the envelope itself. While the Pop III GRB is estimated to be energetic (Eγ,iso ~ 1055 erg), the supergiant envelope hides the initial bright phase in the cocoon component, leading to a GRB with a long duration ~1000 (1 + z) s and an ordinary isotropic luminosity ~ 1052 erg s−1 (~ 10−9 erg cm−2 s−1 at redshift z ~ 20), although these quantities are found to be sensitive to the core and envelope mass. We also show that Pop III.2 GRBs (which are primordial but affected by radiation from other stars) occur >100 times more frequently than Pop III.1 GRBs, and thus should be suitable targets for future X-ray and radio missions. The radio transient surveys are already constraining the Pop III GRB rate and promising in the future.
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Klose, S., S. Schmidl, D. A. Kann, A. Nicuesa Guelbenzu, S. Schulze, J. Greiner, F. Olivares E., et al. "Four GRB supernovae at redshifts between 0.4 and 0.8." Astronomy & Astrophysics 622 (February 2019): A138. http://dx.doi.org/10.1051/0004-6361/201832728.
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Twenty years ago, GRB 980425/SN 1998bw revealed that long gamma-ray bursts (GRBs) are physically associated with broad-lined type-Ic supernovae (SNe). Since then more than 1000 long GRBs have been localized to high angular precision, but only in ∼50 cases has the underlying SN component been identified. Using the Gamma-Ray Burst Optical Near-Infrared Detector (GROND) multi-channel imager at ESO/La Silla, during the last ten years we have devoted a substantial amount of observing time to reveal and study SN components in long-GRB afterglows. Here we report on four more GRB SNe (associated with GRBs 071112C, 111228A, 120714B, and 130831A) which were discovered and/or followed-up with GROND and whose redshifts lie between z = 0.4 and 0.8. We study their afterglow light curves, follow the associated SN bumps over several weeks, and characterize their host galaxies. Using SN 1998bw as a template, the derived SN explosion parameters are fully consistent with the corresponding properties of the currently known GRB-SN ensemble, with no evidence for an evolution of their properties as a function of redshift. In two cases (GRB 120714B/SN 2012eb at z = 0.398 and GRB 130831A/SN 2013fu at z = 0.479) additional Very Large Telescope (VLT) spectroscopy of the associated SNe revealed a photospheric expansion velocity at maximum light of about 40 000 and 20 000 km s−1, respectively. For GRB 120714B, which was an intermediate-luminosity burst, we find additional evidence for a black-body component in the light of the optical transient at early times, similar to what has been detected in some GRB SNe at lower redshifts.
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Krühler, Thomas. "The host galaxies of long gamma-ray bursts through cosmic time." International Journal of Modern Physics D 27, no. 13 (October 2018): 1842001. http://dx.doi.org/10.1142/s0218271818420014.
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As a result of their unprecedented luminosity, long [Formula: see text]-ray bursts (GRBs) and their afterglows pinpoint a population of high-redshift galaxies that is distinct and complementary to galaxies selected by deep sky surveys. In this way, GRBs facilitate a unique view into the high-redshift universe. The bright optical afterglow, for example, serves as a background light for absorption-line spectroscopy, and thus helps us to accurately characterize and understand the cosmochemical evolution of the interstellar matter, the properties of star-forming galaxies through cosmic time or dust extinction at redshifts up to [Formula: see text]. Similarly, detailed studies of the GRB explosion site, and the specific stellar population and galactic environment linked to the GRB, provide important constraints on the physical properties of the GRB progenitor like stellar mass, or on the interplay between metallicity and GRB formation. In this paper, we review recent results in both areas, focusing on novel results from extensive host observations of well-selected GRB samples.
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Tunnicliffe, Rachel L., and Andrew Levan. "GRB 100816A and the nature of intermediate duration gamma-ray bursts." Proceedings of the International Astronomical Union 7, S279 (April 2011): 415–16. http://dx.doi.org/10.1017/s1743921312013610.
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AbstractGamma-ray bursts are normally split into two classes, primarily determined by their observed duration, so called long (> 2s) and short (< 2s) GRBs. There have been many claims of a third duration class, with emission lasting for intermediate periods between 2 - 5s, although the reality of this class remains controversial. Here, we investigate this further utilising the 2.9s duration, spectrally hard GRB 100816A. This burst lies well offset from its host galaxy, has no evidence for an associated supernova (albeit to only moderately constraining limits), and has properties which appear to be genuinely intermediate between long- and short- population bursts. We extend this analysis by comparing the physical locations of a population of intermediate duration GRBs with those of short-GRBs and long-GRBs, concluding that the intermediate sample is indistinguishable from the long-GRB population, whose locations are very different from other transients.
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PERNA, ROSALBA. "THE INTERACTION BETWEEN GAMMA-RAY BURSTS AND THEIR ENVIRONMENT." Modern Physics Letters A 18, no. 37 (December 7, 2003): 2611–25. http://dx.doi.org/10.1142/s0217732303012234.
Full textAbstract:
Gamma-ray Bursts (GRBs) are the most energetic and most relativistic phenomenon in the Universe. Understanding the nature of their progenitors is among the primary efforts of current research in high energy astrophysics, and their unmatched luminosity and other properties makes them ideal cosmological probes. This review summarizes the observational effects resulting from the interaction between the longer-wavelength radiation accompanying GRBs and their close environment. In particular, it discusses signatures that, in addition to providing powerful clues on the GRB progenitors, can also shed light on the physical characteristics, such as metallicity and dust content, of the GRB host galaxies. The last part of the article reviews the long-term signatures imprinted in the medium after a GRB explosion, particularly focusing on how we can identify GRB remnants in our own and nearby galaxies, and what we can learn from their identification.
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Rhodes, L., A. J. van der Horst, R. Fender, I. M. Monageng, G. E. Anderson, J. Antoniadis, M. F. Bietenholz, et al. "Radio afterglows of very high-energy gamma-ray bursts 190829A and 180720B." Monthly Notices of the Royal Astronomical Society 496, no. 3 (June 17, 2020): 3326–35. http://dx.doi.org/10.1093/mnras/staa1715.
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ABSTRACT We present high-cadence multifrequency radio observations of the long gamma-ray burst (GRB) 190829A, which was detected at photon energies above 100 GeV by the High Energy Stereoscopic System (H.E.S.S.). Observations with the Meer Karoo Array Telescope (MeerKAT, 1.3 GHz) and Arcminute Microkelvin Imager – Large Array (AMI-LA, 15.5 GHz) began one day post-burst and lasted nearly 200 d. We used complementary data from Swift X-Ray Telescope (XRT), which ran to 100 d post-burst. We detected a likely forward shock component with both MeerKAT and XRT up to over 100 d post-burst. Conversely, the AMI-LA light curve appears to be dominated by reverse shock emission until around 70 d post-burst when the afterglow flux drops below the level of the host galaxy. We also present previously unpublished observations of the other H.E.S.S.-detected GRB, GRB 180720B from AMI-LA, which shows likely forward shock emission that fades in less than 10 d. We present a comparison between the radio emission from the three GRBs with detected very high energy (VHE) gamma-ray emission and a sensitivity-limited radio afterglow sample. GRB 190829A has the lowest isotropic radio luminosity of any GRB in our sample, but the distribution of luminosities is otherwise consistent, as expected, with the VHE GRBs being drawn from the same parent distribution as the other radio-detected long GRBs.