Relevant bibliographies by topics / Nuclear Astrophysics studies

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Nuclear Astrophysics studies'

Author: Grafiati
Published: 21 February 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Nuclear Astrophysics studies.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Nuclear Astrophysics studies"

1

Gyürky, György. "Challenges and Requirements in High-Precision Nuclear Astrophysics Experiments." Universe 8, no. 4 (March 28, 2022): 216. http://dx.doi.org/10.3390/universe8040216.

Full text
Abstract:
In the 21th century astronomical observations, as well as astrophysical models, have become impressively precise. For a better understanding of the processes in stellar interiors, the nuclear physics of astrophysical relevance—known as nuclear astrophysics—must aim for similar precision, as such precision is not reached yet in many cases. This concerns both nuclear theory and experiment. In this paper, nuclear astrophysics experiments are put in focus. Through the example of various parameters playing a role in nuclear reaction studies, the difficulties of reaching high precision and the possible solutions are discussed.
APA, Harvard, Vancouver, ISO, and other styles
2

Trache, Livius. "Nuclear astrophysics studies at NIPNE." EPJ Web of Conferences 227 (2020): 01016. http://dx.doi.org/10.1051/epjconf/202022701016.

Full text
Abstract:
I will present results of doing nuclear astrophysics research at the National Institute for Physics and Nuclear Engineering, Bucharest-Magurele in the last 2-3 years. Own Nuclear Astrophysics Group (NAG) is focused on the basic types of experiments: -Direct measurements at low and very low energies with ion or alpha beams from the local 3 MV tandetron accelerator. We concentrate on activation measurements. The use of the ultra-low background laboratory in a salt mine at Slanic-Prahova, about 120 km away and of a beta-gamma coincidence unit at home is providing competitive sensitivity. -Indirect measurements done with beams at international facilities with radioactive beams: TAMU and RIBF RIKEN. With help from colleagues, I will mention some theory advances, too.
APA, Harvard, Vancouver, ISO, and other styles
3

RAUSCHER, THOMAS. "THE PATH TO IMPROVED REACTION RATES FOR ASTROPHYSICS." International Journal of Modern Physics E 20, no. 05 (May 2011): 1071–169. http://dx.doi.org/10.1142/s021830131101840x.

Full text
Abstract:
This review focuses on nuclear reactions in astrophysics and, more specifically, on reactions with light ions (nucleons and α particles) proceeding via the strong interaction. It is intended to present the basic definitions essential for studies in nuclear astrophysics, to point out the differences between nuclear reactions taking place in stars and in a terrestrial laboratory, and to illustrate some of the challenges to be faced in theoretical and experimental studies of those reactions. The discussion revolves around the relevant quantities for astrophysics, which are the astrophysical reaction rates. The sensitivity of the reaction rates to the uncertainties in the prediction of various nuclear properties is explored and some guidelines for experimentalists are also provided.
APA, Harvard, Vancouver, ISO, and other styles
4

Robertson, Daniel, Manoel Couder, Uwe Greife, Frank Strieder, and Michael Wiescher. "Underground nuclear astrophysics studies with CASPAR." EPJ Web of Conferences 109 (2016): 09002. http://dx.doi.org/10.1051/epjconf/201610909002.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Langanke, K., and G. Martínez-Pinedo. "Shell model studies for nuclear astrophysics." Journal of Physics: Conference Series 580 (February 9, 2015): 012033. http://dx.doi.org/10.1088/1742-6596/580/1/012033.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Cesaratto, J. M., A. E. Champagne, T. B. Clegg, M. Q. Buckner, R. C. Runkle, and A. Stefan. "Nuclear astrophysics studies at LENA: The accelerators." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 623, no. 3 (November 2010): 888–94. http://dx.doi.org/10.1016/j.nima.2010.08.104.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Motobayashi, T. "Nuclear structure and astrophysics studies at RIKEN." Progress in Particle and Nuclear Physics 59, no. 1 (July 2007): 32–41. http://dx.doi.org/10.1016/j.ppnp.2006.12.034.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Laird, A. M., L. Buchmann, and T. Davinson. "Charged-particle reaction studies for nuclear astrophysics." Hyperfine Interactions 225, no. 1-3 (October 18, 2013): 207–14. http://dx.doi.org/10.1007/s10751-013-0899-1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Olin, Art, Shawn Bishop, Lothar Buchmann, Mohan L. Chatterjee, Alan Chen, John M. D'Auria, Sabine Engel, et al. "Nuclear astrophysics at ISAC with DRAGON: Initial studies." Nuclear Physics A 721 (June 2003): C1019—C1023. http://dx.doi.org/10.1016/s0375-9474(03)01275-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

MOTOBAYASHI, TOHRU. "NUCLEAR STRUCTURE AND NUCLEAR ASTROPHYSICS STUDIES WITH FAST HEAVY-ION BEAMS." International Journal of Modern Physics E 18, no. 10 (November 2009): 1965–69. http://dx.doi.org/10.1142/s0218301309014093.

Full text
Abstract:
Collaboration between France and Japan on studies with fast RI (radioactive isotope) beams and related technical developments started in 1980s, when the GANIL accelerators and RIKEN cyclotron complex started operation and RI beam production technique was developed. Several examples of collaboration on nuclear physics and nuclear astrophysics experiments including related technical development are discussed.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Nuclear Astrophysics studies"

1

Doherty, Daniel Thomas. "Experimental studies for explosive nuclear astrophysics." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/18022.

Full text
Abstract:
In the ejecta from ONe novae outbursts nuclei up to A~40 are observed. The 30P(p,γ)31S reaction is thought to be the bottleneck for the production of all elements heavier than sulphur. However, due to uncertainties in the properties of key proton-unbound resonances the reaction rate is not well determined. In this thesis work, excited states in 31S were populated via the 28Si(4He,n) light-ion fusion-evaporation reaction and the prompt electromagnetic radiation was then detected with the GAMMASPHERE detector array. This γ-ray spectroscopy study, and comparisons with the stable mirror nucleus 31P, allowed the determination of the 31S level structure below the proton-emission threshold and also of the key proton-unbound states for the 30P(p,γ)31S reaction. In particular, transitions from key, low-spin states were observed for the first time. This new information was then used for the re-evaluation of the 30P(p,γ)31S reaction in the temperature range relevant for ONe novae. The newly calculated rate is higher than previous estimates implying a greater flux of material processed to high-Z elements in novae. Astrophysical X-ray bursts are thought to be a result of thermonuclear explosions on the atmosphere of an accreting neutron star. Between these bursts, energy is thought to be generated by the hot CNO cycles. The 15O(α,γ)19Ne reaction is one reaction that allows breakout from these CNO cycle and into the rp-process to fuel outbursts. The reaction is expected to be dominated by a single 3/2+ resonance at 4.033 MeV in 19Ne, however, limited information is available on this key state. This thesis work reports on a pioneering study of the 20Ne(p,d)19Ne reaction in inverse kinematics performed at the Experimental Storage Ring (ESR) as a means of accessing the 4.033-MeV state in 19Ne. The unique background free, high luminosity conditions of the ESR were utilised for this, the first transfer reaction performed at the ESR. The results of this pioneering test experiment are presented along with suggestions for future measurements at storage ring facilities.
APA, Harvard, Vancouver, ISO, and other styles
2

Altana, Carmen Loredana. "The role of nanostructured targets in Laser-Produced Plasmas for Nuclear Astrophysics studies." Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3737.

Full text
Abstract:
This PhD thesis documents the experimental study of plasmas produced from the interaction of a high-power laser in ns domain with nanostructured materials compared with ordinary bulk target. The study is focused on the effect of solid targets with different physical and geometric characteristics, and has the purpose to asses the effects of nanoscale structures in laser-matter interaction and in plasma formation. The motivation for these experiments arises from the fact that there is the possibility of producing plasmas with density and temperature characteristics suitable for nuclear fusion studies, relevant in astrophysics. The optimization of the specific characteristics of nanomaterials, containing metal nanowires, could lead to a stagnant, hotter and denser plasma and to implement the above mentioned studies successfully. The nanostructured targets used in this study are metamaterials consisting in aligned metal nanowires grown by electrodeposition into a porous alumina matrix, obtained on a thick aluminium substrate. These materials were developed with different length, diameter, metal and deposition technique in order to maximize absorption in the visible and IR wavelengths. Various diagnostics were employed for the characterization of the Laser Produced Plasma (LPP). In particular, an Intensified CCD camera in visible domain has been a useful diagnostic tools to understand the expansion dynamics of laser created plumes, by providing a two-dimensional snap shots of the three-dimensional LPP propagation. Depending upon the target material, the generated plume s ion emission features (velocity, flux) as well as plasma properties (temperature, density) are varied even at constant laser intensity. The use of a CCD-camera in X-rays domain has allowed to investigate the X-ray emissivity of laser-produced plasmas. By coupling the detector with an array of pinhole, spectral selection of X-ray emission has been implemented. The Time of Flight measurements have provided a technique to determine the velocity distribution of the plasma at large distances from the target surface, complementarily to velocity estimated by visible imaging close to target surface. Moreover, morphological analysis of craters formed for the laser irradiation was performed by using an optical microscope. The cross-analysis of various diagnostics has immediately showed the differences between an ordinary Al-bulk target and nanostructured materials: bulk aluminium plasma has shorter duration, X-ray flux and ablation efficiency than all other. Finally, preliminary investigations of ion energy spectra, obtained with a Thomson Parabola Spectrometer, were carried out to better understand the nuclear fusion process in a plasma. Temperature estimated are in good agreement with the occurrence of nuclear fusions. All these experimental evidences have taken a further step towards the application of laser driven nuclear reactions.
APA, Harvard, Vancouver, ISO, and other styles
3

Wallace, Jennifer Patrita. "Studies of the structure of the Tz = -1 Nuclei 20Na and 30S for explosive astrophysics." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8039.

Full text
Abstract:
In explosive astrophysical environments such as novae, X-ray bursters and supernovae, conditions of extreme temperature and density are achieved. Under such conditions, both the rate of energy release and path of nucleosynthesis are governed by reactions on unstable nuclei. In this light, direct reaction studies using radioactive ion beams play a vital role in determining nuclear reaction rates. However, in the vast majority of cases, direct measurements are not possible and as such, indirect measurements are equally important for the understanding of the main reaction processes driving astrophysical events. In this thesis work, indirect studies of the astrophysically important 19Ne(p,γ)20Na and 29P(p,γ)30S reactions have been performed. For the first reaction, a β-delayed proton decay study of 20Mg was performed to gain information about the spin-parity assignment of the first key resonance above the proton emission threshold in the compound nucleus 20Na. This resonance is expected to dominate the 19Ne(p,γ)20Na reaction rate in explosive astrophysical environments and its identity has been under discussion for a long time, with J π = 1+ and 3+ assignments suggested. In the present study an upper limit on the β-decay branch to this state of 0.02% with a con dence level of 90% is reported. This is signi cantly more stringent than previous studies and makes a 1+ assignment highly unlikely, favouring instead a 3+ assignment. A 3+ assignment is predicted to have a signi cantly higher resonance strength and produce a proportionately higher 19Ne(p,γ)20Na reaction rate in X-ray burst conditions. The second study performed was a detailed gamma-ray spectroscopy study of the nucleus 30S. Excitation energies have been determined with improved precision over previous studies and the first,firm spin-parity assignments of key 29P + p resonant states, expected to dominate the 29P(p,γ)30S reaction in stellar scenarios, have been made. An evaluation of the 29P(pγ)30S reaction over the temperature range T = 0.06-2.5 GK shows that the 3+ and 2+ resonant states located at Er = 292.0(9) and 413.1(10) keV, respectively, dominate the 29P(p,γ)30S reaction rate in ONe novae, while the 413 keV resonance is expected to govern the rate in X-ray burster environments. These new, precise resonance energy measurements and firm spin-parity assignments have signi cantly reduced uncertainties in the 29P(p,γ)30S reaction in ONe novae and X-ray bursters. In particular, the reaction rate is now speci ed precisely enough for calculations of isotopic abundances in ONe novae ejecta.
APA, Harvard, Vancouver, ISO, and other styles
4

Liu, Hang. "Studies of the Nuclear Three-Body System with Three Dimensional Faddeev Calculations." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1127332785.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Hubbard, Nicolas. "Studies of the nuclear structure of 12C and the astrophysical production of 23Na." Thesis, University of York, 2018. http://etheses.whiterose.ac.uk/20690/.

Full text
Abstract:
Nuclear reactions can be used to study both the structure of the atomic nucleus, and to study the evolution of stars and the Universe. In this thesis two experiments are presented: one studying the astrophysical impact of the 23Na(a,p)26Mg reaction, and one studying the nuclear structure of 12C near the proton separation energy of 16 MeV. The 23Na(a,p)26Mg reaction is an important reaction affecting the abundances of 23Na and the radioisotope 26Al in massive stars. Before 2014 experimental and theoretical data on this reaction was of unknown uncertainty. A new direct measurement of the 23Na(a,p)26Mg reaction was performed at Aarhus University and with two other independent modern measurements of the 23Na(a,p)26Mg reaction a new combined experimental reaction rate has been calculated with an uncertainty of 30%, and the impact on 23Na and 26Al production has been modelled and the abundances constrained by this reaction. 12C is a light, stable, and well-studied nucleus with current research generally on clustering phenomena. It is therefore unusual that a narrow shell-model predicted state with spin-parity 0- has not been experimentally observed already. Excited states of 12C were populated via the 11B(3He,d)12C reaction at iThemba LABS in South Africa, and analysed through R-matrix theory. No 0- state was observed in the region predicted by the shell-model, but a likely 0- state has been identified above the proton separation energy, and a detailed analysis of its properties using R-matrix theory is presented.
APA, Harvard, Vancouver, ISO, and other styles
6

Marta, Michele. "The 14N(p,γ)O15 reaction studied at low and high beam energy." Forschungszentrum Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-93642.

Full text
Abstract:
The Bethe-Weizsäcker cycle consists of a set of nuclear reactions that convert hydrogen into helium and release energy in the stars. It determines the luminosity of low-metal stars at their turn-off from the main-sequence in the Hertzsprung-Russel diagram, so its rate enters the calculation of the globular clusters’ age, an independent lower limit on the age of the universe. The cycle contributes less than 1% to our Sun’s luminosity, but it produces neutrinos that can in principle be measured on Earth in underground experiments and bring direct information of the physical conditions in the solar core, provided that the nuclear reaction rate is known with sufficient precision. The 14N(p,γ)15O reaction is the slowest reaction of the Bethe-Weizs¨acker cycle and establishes its rate. Its cross section is the sum of the contributions by capture to different excited levels and to the ground state in 15O. Recent experiments studied the region of the resonance at Ep = 278 keV. Only one modern data set from an experiment performed in 1987 is available for the high-energy domain. Both energy ranges are needed to constrain the fit of the excitation function in the R-matrix framework and to obtain a reliable extrapolated S-factor at the very low astrophysical energies. The present research work studied the 14N(p,γ)15O reaction in the LUNA (Laboratory for Underground Nuclear Astrophysics) underground facility at three proton energies 0.36, 0.38, 0.40MeV, and in Dresden in the energy range Ep = 0.6 - 2MeV. In both cases, an intense proton beam was sent on solid titanium nitride sputtered targets, and the prompt photons emitted from the reaction were detected with germanium detectors. At LUNA, a composite germanium detector was used. This enabled a measurement with dramatically reduced summing corrections with respect to previous studies. The cross sections for capture to the ground state and to the excited states at 5181, 6172, and 6792 keV in 15O have been determined. An R-matrix fit was performed for capture to the ground state, that resolved the literature discrepancy of a factor two on the extrapolated S-factor. New precise branching ratios for the decay of the Ep = 278 keV resonance were measured. In Dresden, the strength of the Ep = 1058 keV resonance was measured relative to the well-known resonance at Ep = 278 keV, after checking the angular distribution. Its uncertainty is now half of the error quoted in literature. The branching ratios were also measured, showing that their recommended values should be updated. Preliminary data for the two most intense transitions off resonance are provided. The presence in the targets of the other stable nitrogen isotope 15N with its well- known isotopic abundance, allowed to measure the strength of two resonances at Ep = 430 and 897 keV of the 15N(p,αγ)12 C reaction, improving the precision for hydrogen depth profiling.
APA, Harvard, Vancouver, ISO, and other styles
7

Schmidt, Alex Andre. "Stellar population studies in galaxy nuclei : a practical approach to the population synthesis problem." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334676.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Sinclair, Laura. "Decay studies of proton-rich nuclei in the mass 70 region and investigating their effects on the astrophysical rp-process." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/17298/.

Full text
Abstract:
Proton-rich A~70 nuclei have been subject to many experimental investigations due to their accessibility since the advent of radioactive ion beams and improved experimental developments in sensitive tagging techniques. Nuclear structure data in this region are also of astrophysical significance since the (rapid proton capture) rp-process, which is believed to take place in X-ray bursts, occurs in the vicinity of the N=Z line, with rapid proton-capture chains and subsequent beta-decays allowing for the seeding of heavy elements in the A~100 region. Therefore the structure and decay properties of N~Z nuclei can have an impact on rp-process reaction rate calculations. The nuclide 72Kr, with a beta-decay half-life of 17.1(2) s, is a potential waiting point of the rp-process. However, its lifetime in a stellar environment is reduced by the two-proton capture reaction 72Kr(p,g)73Rb(p,g)74Sr. One of the main goals of the experiment was to measure the proton-separation energy, Sp, of 73Rb, by extracting the beta-delayed spectrum following the decay of 73Sr. To gain a complete picture of the two-proton capture branch for the 72Kr waiting point in the rp-process the half-life of 74Sr needs to be measured. An experiment was carried out at the Radioactive Isotope Beam Factory, RIKEN. The nuclei of interest were produced by the fragmentation of a 345 MeV/nucleon 124Xe beam on a 555 mg/cm^2 9Be target. The effects of the half-lives and proton-separation energy measured, in this work, on the effective lifetime of 72Kr have been explored using one-zone, one-dimensional reaction network calculations for the astrophysical rp-process. At the proton drip-line, a search for new isotopes and the nature of the decay of 76Y was conducted. The location of the drip line is of important interest for the rp-process. An estimate of the half-life and an upper limit of the half-life for 72Rb and 73Rb have been determined, respectively. Following these measurements, proton emission calculations have been performed by L.S. Ferreria and E. Maglione and the results are discussed in this work.
APA, Harvard, Vancouver, ISO, and other styles
9

Marta, Michele. "The 14N(p,γ)15O reaction studied at low and high beam energy." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-87464.

Full text
Abstract:
The CNO cycle consists of a set of nuclear reactions that convert hydrogen into helium and releases energy in stars. The cycle contributes less than 1% to our Sun's luminosity, but it is responsible for detectable neutrino fluxes that can bring direct information of the physical conditions in the solar core, provided that the nuclear reaction rate is known with sufficient precision. The 14N(p,γ)15O is the slowest reaction in the CNO cycle and estabilishes its rate. The experimental study has been performed both at the LUNA 400 kV accelerator deep underground in the Gran Sasso mountain in Italy and at a 3 MV Tandetron in the Helmholtz-Zentrum Dresden-Rossendorf. A proton beam was sent on solid TiN targets and the prompt photons were collected by a composite HPGe detector (at LUNA) or by up to four HPGe detectors (Dresden). The obtained results improve the fit of the excitation function in the R-matrix framework, that is used to extrapolate the S-factor at the very low astrophysical energies. In addition, the strength of two resonances at Ep = 430 and 897 keV of the 15N(p,αγ)12C reaction were measured, improving the precision for hydrogen depth profiling.
APA, Harvard, Vancouver, ISO, and other styles
10

D'AMMANDO, FILIPPO. "Multiwavelength studies of the blazars detected by AGILE." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1199.

Full text
Abstract:
La scoperta dell’emissione nei raggi gamma da parti di numerosi Nuclei Galattici Attivi (AGN) con EGRET ed i telescopi Cherenkov è stata una delle più rivoluzionarie scoperte di astrofisica delle alte energie degli ultimi 20 anni, portando all’identificazione di una nuova classe di AGN: i blazar. I blazar sono la sottoclasse più estrema di AGN, caratterizzata da forte emissione di radiazione non-termica attraverso l'intero spettro elettromagnetico. Questa emissione è interpretata come il risultato della radiazione elettromagnetica da un getto relativistico allineato alla linea di vista dell'osservatore, causando una forte amplificazione relativistica dell’emissione osservata. Considerando che la maggiore frazione della potenza totale dei blazar è emessa nei raggi gamma, le informazioni in questa banda energetica sono fondamentali per studiare i diversi modelli di radiazione. Oltre dieci anni dopo l'epoca di EGRET, il satellite AGILE (e successivamente anche il satellite Fermi) ha colmato la lacuna nella banda MeV-GeV dando ulteriore impulso allo studio dei fenomeni di astrofisica delle alte energie nei blazar. Tuttavia, nonostante l'importanza delle informazioni fornite dalle osservazioni nei raggi gamma, studi correlati multifrequenza sono la chiave per raggiungere una migliore comprensione della struttura interna del getto, l'origine dei fotoni seme per il processo di Compton inverso ed i meccanismi di emissione che agiscono nei blazar. Dal suo lancio in Aprile 2007, il satellite AGILE ha rilevato diversi blazar in stato di alta attività: PKS 1510-089, S5 0716+714, 3C 454.3, 3C 273, 3C 279, W Comae, Mrk 421 e PG 1553+113. In questa Tesi saranno presentati i risultati più interessanti dell'analisi multifrequenza di queste sorgenti rilevate da AGILE in raggi gamma, insieme ai dati multifrequenza forniti da altri osservatori come Spitzer, Swift, RXTE, Suzaku, INTEGRAL, MAGIC, VERITAS, nonché dalle osservazioni dal radio all’ottico ottenute da GASP-WEBT e REM. Questa ampia copertura multifrequenza mi ha offerto l'opportunità di studiare le distribuzioni spettrali di energia di queste sorgenti dal radio ai raggi gamma, le variabilità correlata in diverse bande di energia e di indagare i meccanismi responsabili per la loro emissione, scoprendo in alcuni casi un comportamento più complesso rispetto ai modelli standard.
The discovery of emission in the gamma-ray domain from many Active Galactic Nuclei (AGNs) by EGRET onboard Compton Gamma-Ray Observatory and the Cherenkov Telescopes was one of the most breakthrough of high energy astrophysics in the last 20 years, leading to the identification of a new class of AGNs: the blazars. Blazars are the most extreme subclass of AGNs, characterized by the emission of strong non-thermal radiation across the entire electromagnetic spectrum, from radio to very high gamma-ray energies. This emission is interpreted as the result of the electromagnetic radiation from a relativistic jet that is viewed closely aligned to the line of sight of the observer, thus causing strong relativistic amplification. Considering that the large fraction of the total power of blazars is emitted in the gamma-rays, information in this energy band is crucial to study the different radiation models. More than ten years after the EGRET era, the AGILE satellite (and subsequently also the Fermi satellite) filled the gap in the MeV-GeV band giving further impulse to the study of the high-energy astrophysics phenomena in blazars. However, notwithstanding the importance of the information provided by the gamma-ray observations, correlated multiwavelength studies are the key to achieve a better understanding of the structure of the inner jet, the origin of the seed photons for the inverse Compton process and the emission mechanisms at work in blazars. Since its launch in April 2007, the AGILE satellite detected several blazars in high activity state: PKS 1510–089, S5 0716+714, 3C 454.3, 3C 273, 3C 279, W Comae, Mrk 421 and PG 1553+113. In this Thesis I will present the most interesting results on multifrequency analysis of these sources detected by AGILE in gamma-rays, together with the multiwavelength data from other observatories such as Spitzer, Swift, RXTE, Suzaku, INTEGRAL, MAGIC, VERITAS, as well as radio-to-optical coverage by means of GASP-WEBT and REM. This large multifrequency coverage gave me the opportunity to study the Spectral Energy Distributions (SEDs) of these sources from radio to gamma-rays, the correlated variability in different energy bands and to investigate the mechanisms responsible for their emission, uncovering in some cases a more complex behaviour with respect to the standard models. The intense gamma-ray flares of S5 0716+714 observed by AGILE in September and October 2007 are among the highest fluxes detected by a BL Lac object and considering the redshift of the source (z = 0.31) the total power transported in the jet during these episodes approaches or slightly exceeds the maximum power generated by a spinning black hole of 10^9 solar masses, challenging the Blandford-Znajek mechanism and confirming the extreme energetics during these flares. The modeling of the SEDs of S5 0716+714 indicated as, even if the broad band emission appears in agreement with the synchrotron self Compton (SSC) paradigm, a more complex model with two SSC components is needed to interpret our data. The case of S5 0716+714 is not unique among the BL Lac objects, also for the multifrequency observation of Mrk 421 and W Comae in June 2008 a one-zone SSC model seems to be a good representation of the broad band spectrum, but the observations collected during the multiwavelength campaigns seem to open to more complex interpretations of the data. Moreover, the dominant emission mechanism in the gamma-ray band for Flat Spectrum Radio Quasars (FSRQs) is the inverse Compton scattering of external photons from the broad line region, but in some particular states also the contribution of seed photons from a hot corona (3C 454.3 in December 2007) or the accretion disk (3C 279) are shown to be important. Therefore, from the modeling of the different SEDs of BL Lacs and FSRQs observed by AGILE seems to emerge that the SSC and the external Compton (EC) frameworks, respectively, are good approximation for describing on average the high activity states of the two flavours of blazars, but going into details of the single observation more complex scenarios sometimes are requested. The possibility to obtain information over the entire electromagnetic spectrum during the multifrequency campaigns organized by AGILE gave me also the opportunity to investigate in some blazars the presence of Seyfert-like features, such as the little and big blue bumps (PKS 1510-089) and the Compton reflection component (3C 273). Moreover, we revealed in the FSRQ PKS 1510-089 some features typical of High-frequency peaked BL Lac objects, such a X-ray harder-when-brighter behaviour during March 2008 and a shift of the synchrotron peak towards higher frequencies during the huge flare of March 2009. Emission in optical and gamma-ray bands seems to be correlated during high activity states of blazars, but not strongly, with a possible lag of the gamma-ray flux with respect to optical one less than one day, both for FSRQs (e.g. 3C 454.3) and BL Lacs (S5 0716+714). On the other hand, during March 2009 a possible delay of the optical emission with respect to the gamma-ray one is detected for PKS 1510-089, suggesting a more complex behaviour in the optical/gamma-ray correlation, especially for FSRQs, where also a contribution of the thermal disk emission is clearly visible.
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Nuclear Astrophysics studies"

1

Urry, Claudia Megan. X-ray temporal and spectral studies of blazars with the Ginga satellite: Final report for NASA grant, NAG8-697. Baltimore, MD: Space Telescope Science Institute, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

M, Dirac P. A. High-Energy Physics: In Honor of P.A.M. Dirac in His Eightieth Year (Studies in the Natural Sciences, Vol 20). Plenum Pub Corp, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

(Editor), H. V. Klapdor-Kleingrothaus, and I. V. Krivosheina (Editor), eds. Lepton and Baryon Number Violation in Particle Physics, Astrophysics and Cosmology: Proceedings of the First International Symposium on Lepton and Baryon ... Theoretical Studies (ECT), Trento, Italy, 2. Taylor & Francis, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Klapdor-Kleingrothaus, H. V., and I. V. Krivosheina. Lepton and Baryon Number Violation in Particle Physics, Astrophysics and Cosmology: Proceedings of the First International Symposium on Lepton and Baryon Number Violation , European Centre for Theoretical Studies , Trento, Italy, 2. Taylor & Francis Group, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lepton and Baryon Number Violation in Particle Physics, Astrophysics and Cosmology: Proceedings of the First International Symposium on Lepton and Baryon Number Violation , European Centre for Theoretical Studies , Trento, Italy, 2. Taylor & Francis Group, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Danilov, V. M. Non-stationarity of Open Star Clusters. Ural University Press, 2021. http://dx.doi.org/10.15826/b978-5-7996-3173-4.

Full text
Abstract:
The monograph poses issues related to the study of the non-stationarity of open star clusters (OSCs), starting with an analysis of the properties of the trajectories of individual stars to the study of collective motion of stars. A discussion of the dynamics of correlations and wave processes in such clusters is presented. The mechanisms of the dynamic evolution of OSCs, the gravitational instability of OSC nuclei, the spectra of frequencies and wavenumbers for oscillations of numerical models of OSCs, astrophysical applications of the results of studies of the dynamics of OSCs are considered. We address the monograph to academic researchers (astronomers and physicists) who are interested in astrophysics, the dynamics of stellar systems, and PhD and senior students of relevant specialities.
APA, Harvard, Vancouver, ISO, and other styles
7

United States. National Aeronautics and Space Administration., ed. X-ray temporal and spectral studies of blazars with the Ginga satellite: Final report for NASA grant, NAG8-697. Baltimore, MD: Space Telescope Science Institute, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

United States. National Aeronautics and Space Administration., ed. X-ray temporal and spectral studies of blazars with the Ginga satellite: Final report for NASA grant, NAG8-697. Baltimore, MD: Space Telescope Science Institute, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Nuclear Astrophysics studies"

1

Laird, A. M., L. Buchmann, and T. Davinson. "Charged-particle reaction studies for nuclear astrophysics." In ISAC and ARIEL: The TRIUMF Radioactive Beam Facilities and the Scientific Program, 207–14. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7963-1_23.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Frogel, Jay A. "Optical and Infrared Studies of Stellar Populations: The Galactic Nuclear Bulge." In Astrophysics and Space Science Library, 1–14. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2919-7_1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Rolfs, C. "Data Needs in Astrophysical Studies." In Nuclear Data for Science and Technology, 625–28. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-58113-7_178.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Saavedra, Oscar. "Cosmic Ray Studies at High Mountain Altitude Laboratories." In Nuclei Far from Stability and Astrophysics, 385–96. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0708-5_33.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Casten, R. F. "Initial Studies of Neutron-Rich Nuclei with Next-Generation Radioactive Beam Facilities." In Nuclei Far from Stability and Astrophysics, 19–29. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0708-5_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Mele, Filippo. "Application Specific Integrated Circuits for High Resolution X and Gamma Ray Semiconductor Detectors." In Special Topics in Information Technology, 31–42. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-85918-3_3.

Full text
Abstract:
AbstractThe increasing demand for performance improvements in radiation detectors, driven by cutting-edge research in nuclear physics, astrophysics and medical imaging, is causing not only a proliferation in the variety of the radiation sensors, but also a growing necessity of tailored solutions for the front-end readout electronics. Within this work, novel solutions for application specific integrated circuits (ASICs) adopted in high-resolution X and $$\upgamma $$ γ ray spectroscopy applications are studied. In the first part of this work, an ultra-low noise charge sensitive amplifier (CSA) is presented, with specific focus on sub-microsecond filtering, addressing the growing interest in high-luminosity experiments. The CSA demonstrated excellent results with Silicon Drift Detectors (SDDs), and with room temperature Cadmium-Telluride (CdTe) detectors, recording a state-of-the-art noise performance. The integration of the CSA within two full-custom radiation detection instruments realized for the ELETTRA (Trieste, Italy) and SESAME (Allan, Jordan) synchrotrons is also presented. In the second part of this work, an ASIC constellation designed for X-Gamma imaging spectrometer (XGIS) onboard of the THESEUS space mission is described. The presented readout ASIC has a highly customized distributed architecture, and integrates a complete on-chip signal filtering, acquisition and digitization with an ultra-low power consumption.
APA, Harvard, Vancouver, ISO, and other styles
7

G. Abrahamyan, Martin. "Vortices in Rotating and Gravitating Gas Disk and in a Protoplanetary Disk." In Vortex Dynamics Theories and Applications. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.92028.

Full text
Abstract:
Nonlinear equations describing dynamics of 2D vortices are very important in the physics of the ocean and the atmosphere and in plasma physics and Astrophysics. Here linear and nonlinear 2D vortex perturbations of gravitating and light gaseous disks are examined in the geostrophic and post-geostrophic approximations. In the frame of geostrophic approximation, it is shown that the vortex with positive velocity circulation is characterized by low pressure with negative excess mass density of substance. Vortex with negative circulation has higher pressure and is a relatively tight formation with the positive excess mass density. In the post-geostrophic approximation, structures of the isolated monopole and dipole vortex (modons) solutions of these equations are studied. Two types of mass distributions in dipole vortices are found. The first type of modon is characterized by an asymmetrically positioned single circular densification and one rarefaction. The second type is characterized by two asymmetrically positioned densifications and two rarefactions, where the second densification-rarefaction pair is crescent shaped. The constant density contours of a dipole vortex in a light gas disk coincide with the streamlines of the vortex; in a self-gravitating disk, the constant density contours in the vortex do not coincide with streamlines. Possible manifestations of monopole and dipole vortices in astrophysical objects are discussed. Vortices play decisive role in the process of planet formation. Gas in a protoplanetary disk practically moves on sub-Keplerian speeds. Rigid particles, under the action of a head wind drags, lose the angular momentum and energy. As a result, the ~10 cm to meter-sized particles drift to the central star for hundreds of years. Long-lived vortical structures in gas disk are a possible way to concentrate the ~10 cm to meter sized particles and to grow up them in planetesimal. Here the effect of anticyclonic Burgers vortex on formation of planetesimals in a protoplanetary dusty disc in local approach is also considered. It is shown that the Burgers vortex with homogeneously rotating kernel and a converging radial stream of substance can effectively accumulate in its nuclear area the meter-sized rigid particles of total mass ∼1028 g for characteristic time ∼106 year.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Nuclear Astrophysics studies"

1

Rehm, K. E. "Reaction Studies in Nuclear Astrophysics." In FUSION06: Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier. AIP, 2006. http://dx.doi.org/10.1063/1.2338401.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Aprahamian, Ani. "Nuclear Astrophysics and Nuclear Structure." In NUCLEAR PHYSICS, LARGE AND SMALL: International Conference on Microscopic Studies of Collective Phenomena. AIP, 2004. http://dx.doi.org/10.1063/1.1805934.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Woods, Philip J. "Reaction Studies for Explosive Nuclear Astrophysics." In Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016). Journal of the Physical Society of Japan, 2017. http://dx.doi.org/10.7566/jpscp.14.010502.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

MATOS, M., J. C. BLACKMON, H. E. GARDINER, L. E. LINHARDT, K. T. MACON, L. L. MONDELLO, L. BABY, et al. "THE ARRAY FOR NUCLEAR ASTROPHYSICS STUDIES WITH EXOTIC NUCLEI (ANASEN)." In Proceedings of the Fourteenth International Symposium. WORLD SCIENTIFIC, 2013. http://dx.doi.org/10.1142/9789814383646_0065.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Matos, Milan, Jeff C. Blackmon, Laura E. Linhardt, Laura L. Mondello, Eric Johnson, Grigory ROGACHEV, and Ingo Wiedenhoever. "The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN)*." In 11th Symposium on Nuclei in the Cosmos. Trieste, Italy: Sissa Medialab, 2011. http://dx.doi.org/10.22323/1.100.0226.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Almaraz-Calderon, S., B. Asher, N. Gerken, K. Hanselman, K. E. Rehm, M. Avila, B. P. Kay, et al. "Nuclear Astrophysics Studies with an Isomeric 26Alm Beam." In Sixth International Conference on Fission and Properties of Neutron-Rich Nuclei (ICFN6). WORLD SCIENTIFIC, 2017. http://dx.doi.org/10.1142/9789813229426_0087.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Olin, Art. "Nuclear Astrophysics at ISAC with DRAGON: Initial Studies." In CLASSICAL NOVA EXPLOSIONS: International Conference on Classical Nova Explosions. AIP, 2002. http://dx.doi.org/10.1063/1.1518188.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Bertulani, C. A., Claudi Spitaleri, Claus Rolfs, and Rosario G. Pizzone. "Nuclear astrophysics studies with ultra-peripheral heavy-ion collisions." In FIFTH EUROPEAN SUMMER SCHOOL ON EXPERIMENTAL NUCLEAR ASTROPHYSICS. AIP, 2010. http://dx.doi.org/10.1063/1.3362598.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Yoneda, K. "Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF." In ORIGIN OF MATTER AND EVOLUTION OF GALAXIES 2011. AIP, 2012. http://dx.doi.org/10.1063/1.4763402.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Ejiri, Hiroyasu, Livius Trache, Alexei Smirnov, and Sabin Stoica. "Neutrino Nuclear Responses for Neutrino Studies in Nuclear Femto Laboratories." In EXOTIC NUCLEI AND NUCLEAR∕PARTICLE ASTROPHYSICS (III): From Nuclei to Stars. AIP, 2010. http://dx.doi.org/10.1063/1.3527207.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Nuclear Astrophysics studies"

1

Uwe, Greife. Development of a high-density gas-jet target for nuclear astrophysics and reaction studies with rare isotope beams. Final Report. Office of Scientific and Technical Information (OSTI), August 2014. http://dx.doi.org/10.2172/1149459.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Nuclear Astrophysics studies' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography