Journal articles: 'Optical emission and absorption spectroscopy'

1

Hearnshaw, J. B., and V. J. McIntyre. "Optical spectroscopy of SN 1987A." Publications of the Astronomical Society of Australia 7, no. 4 (1988): 424–30. http://dx.doi.org/10.1017/s132335800002258x.

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AbstractMt John Observatory photographic spectra of SN 1987A have been obtained on 111 nights during the first year at resolutions of 1.1 Å (blue) and 1.6 Å (red). The early spectra are dominated by broad P Cygni profiles from neutral or singly ionised species. Ba absorption lines may be present. After six months nebular emission features emerged, including [OI] 630, 636 nm and two unidentified UV lines (367, 375 nm) in the previously dark region below 380 nm. Absorption line radial velocities show steep declines in the first month, but are almost constant or only slowly decline after 100 days. For the Hα absorption minimum the initial decline rate was 690 ± 70 km s−1d−1 and the initial velocity was −20.2±0.5 Mm s−1 (LMC frame). By 1988 Feb the slowest material in absorption was at −2.2 Mm s−1.The emission maxima of Hα and NaID show anomalous redshifts of about 1.0 Mm s−1. The [OI] lines show no such redshift. Recent [OI] and Hα spectra at higher resolution show ‘fine structure’ in the profiles, indicating inhomogeneity in the ejecta. Hβ, Hγ and Hδ (but not Hα) were all weaker or absent from 1987 late March to early May, but strong thereafter. From about 1987 Mar 18 to Apr 17 Hα showed a bump on the blue side of the emission at 647 nm and a double peak (658 and 668 nm). Absorption bumps in the Hα profile in early spectra (1987 Feb) may be due to circumstellar water vapour.

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Kang, S. J., and V. M. Donnelly. "Optical absorption and emission spectroscopy studies of ammonia-containing plasmas." Plasma Sources Science and Technology 16, no. 2 (February 15, 2007): 265–72. http://dx.doi.org/10.1088/0963-0252/16/2/008.

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Rogoff, Gerald L. "Optical probe for spatially resolved plasma emission and absorption spectroscopy." Applied Optics 24, no. 12 (June 15, 1985): 1733. http://dx.doi.org/10.1364/ao.24.001733.

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Shtan’ko, Viktor, Evgeny Chinkov, Viktor Kolomin, Tatyana Ivanova, and Sergey Stepanov. "Optical Spectroscopy of Barium Fluoride Crystals under Simultaneous Pulsed Excitation." Key Engineering Materials 712 (September 2016): 338–42. http://dx.doi.org/10.4028/www.scientific.net/kem.712.338.

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This paper reports optical absorption spectra and rapidly decaying luminescence of BaF2 crystals measured at 295 K under excitation pulse of accelerated electrons and excited simultaneous stimulated emission of CdSe crystal. It is shown that the simultaneous excitation of the crystals BaF2 pulse accelerated and SE semiconductors in electronic components STE absorption leads to a reduction efficiency of creation of STE and the appearance of fast decaying emission in the UV region of the spectrum.

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Cao, Ping, Yue Bai, and Zhi Qu. "The Structural and Optical Properties of Al Doped ZnO Thin Film." Applied Mechanics and Materials 727-728 (January 2015): 280–83. http://dx.doi.org/10.4028/www.scientific.net/amm.727-728.280.

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Al doped ZnO thin film have been prepared by a sol-gel method. The structural, and optical properties of the sample were investigated. X-ray diffraction and X-ray absorption spectroscopy analyses and UV absorption spectroscopy analyses indicate that Al3+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

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Hui, Qin, John L. Persson, Jaap H. M. Beijersbergen, and Michio Takami. "Laser Spectroscopy of Neutral Atoms in Superfluid Helium: New Environment For Spectroscopy and Chemistry." Laser Chemistry 15, no. 2-4 (January 1, 1995): 221–28. http://dx.doi.org/10.1155/1995/71705.

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The optical spectra of neutral atoms are studied in superfluid helium (HeII). Neutral atoms are dispersed into HeII by laser ablation of solid samples immersed in HeII. Absorption and emission spectra of dispersed atoms are studied with pulsed dye lasers. Ytterbium is found to be a typical bubble atom which resides in a bubble-like cavity formed by a strong repulsive force against the surrounding He atoms. Resonance quenching of LIF by accidental overlap of the resonant induced emission and broad absorption lines is observed.

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Torres, R. M., A. Damineli-Neto, and J. A. de Freitas Pacheco. "Infrared spectroscopy of Be stars." Symposium - International Astronomical Union 162 (1994): 412–13. http://dx.doi.org/10.1017/s0074180900215507.

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FeII emission lines are present in a variety of astrophysical objects and, in particular, in Be stars, where in some situations they can also be seen in absorption. Selvelli & Araujo (1984) studied a sample of classical Be stars that have FeII emission lines in the optical region. The analysis of IUE spectra of those stars revealed that, for the majority of the objects, neither absorption nor emission FeII features were present in the UV. The conclusion was that their data could not support excitation of FeII by continuum fluorescence. On the other hand, FeIII of circumstellar origin is often seen in absorption in the UV spectra of Be stars (Snow & Stalio 1987 and references therein). This could be an indication that the optical FeII emission lines are originated from recombination and cascade. However, Selvelli & Araujo (1984) argued that, since the multiplet UV 191 of FeII does not appear in emission, that mechanism is probably not relevant. In the present work we report new spectroscopic observations in the near infrared of a sample of 60 Be stars, including the prominent FeII 999.7 nm emission line. This line is also present in the spectra of superluminous B stars for which mass loss rates have recently been estimated (Lopes, Damineli-Neto & Freitas Pacheco 1992). We derived mass loss rates from the infrared line luminosities, in agreement with those derived by other methods. We also found a new evidence of the Be envelope flattening through the FeII/Paδ line ratio.

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Schmidt, Timothy W., and Robert G. Sharp. "The Optical Spectroscopy of Extraterrestrial Molecules." Australian Journal of Chemistry 58, no. 2 (2005): 69. http://dx.doi.org/10.1071/ch04269.

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The ongoing quest to identify molecules in the interstellar medium by their electronic spectra in the visible region is reviewed. Identification of molecular absorption is described in the context of the elucidation of the carriers of the unidentified Diffuse Interstellar Bands, and molecular emission is discussed with reference to the unidentified Red Rectangle bands. The experimental techniques employed in undertaking studies on the optical spectroscopy of extraterrestrial molecules are described and critiqued in the context of their application.

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Cazzoli, Sara, Isabel Márquez, Josefa Masegosa, Ascensión del Olmo, Mirjana Pović, Omaira González-Martín, Barbara Balmaverde, Lorena Hernández-García, and Santiago García-Burillo. "Optical spectroscopy of nearby type1-LINERs." Proceedings of the International Astronomical Union 15, S356 (October 2019): 87–92. http://dx.doi.org/10.1017/s174392132000263x.

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AbstractWe present the highlights from our recent study of 22 local (z < 0.025) type-1 LINERs from the Palomar Survey, on the basis of optical long-slit spectroscopic observations taken with TWIN/CAHA, ALFOSC/NOT and HST/STIS. Our goals were threefold: (a) explore the AGN-nature of these LINERs by studying the broad (BLR-originated) Hαλ 6563 component; (b) derive a reliable interpretation for the multiple narrow components of emission lines by studying their kinematics and ionisation mechanism (via standard BPTs); (c) probe the neutral gas in the nuclei of these LINERs for the first time. Hence, kinematics and fluxes of a set of emission lines, from Hβ λ4861 to [SII]λλ 716,6731, and the NaDλλ5890,5896 doublet in absorption have been modelled and measured, after the subtraction of the underlying light from the stellar component.

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Pressel, K., K. Thonke, A. Dörnen, and G. Pensl. "Optical studies on InP:Fe by Fourier-transform emission and absorption spectroscopy." Physical Review B 43, no. 3 (January 15, 1991): 2239–45. http://dx.doi.org/10.1103/physrevb.43.2239.

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Rogoff, Gerald L. "Optical probe for spatially resolved plasma emission and absorption spectroscopy: erratum." Applied Optics 24, no. 17 (September 1, 1985): 2755. http://dx.doi.org/10.1364/ao.24.002755.

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Ab Rasid, Atiqah, Husin Wagiran, Suhairul Hashim, Rosli Hussin, and Zuhairi Ibrahim. "Optical Properties of Undoped and Dy³⁺-Doped Boro-Tellurite Glass." Advanced Materials Research 895 (February 2014): 194–99. http://dx.doi.org/10.4028/www.scientific.net/amr.895.194.

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A series of undoped and Dy3+-doped boro-tellurite glasses were prepared, and their optical properties have been studied through XRD, absorption, optical band gap energy and photoluminescence. The XRD pattern has been used to confirm the amorphous nature of the prepared glass. The optical absorption spectra showed eight absorption bands which corresponded to 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6F11/2 and 6H11/2 transitions from the ground state, 6H15/2. The optical band gap energy, Eopt for undoped glass was 3.08 eV and the Dy3+-doped glasses Eopt values varied from 3.16 3.24 eV. The emission spectra from photoluminescence spectroscopy showed two dominant emission peaks at 483 nm and 574 nm with an excitation wavelength of 325 nm (3.82 eV). Keywords: X-ray diffraction, boro-tellurite glass, photoluminescence, absorption spectrum, UV-Vis spectroscopy, energy band gap.

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Galtier, Sandrine, Christophe Anselmo, Jean-Yves Welschinger, Jean-Pierre Cariou, Jean-François Sivignon, Alain Miffre, and Patrick Rairoux. "Remote sensing of methane emissions by combining optical similitude absorption spectroscopy (OSAS) and lidar." EPJ Web of Conferences 176 (2018): 01010. http://dx.doi.org/10.1051/epjconf/201817601010.

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Monitoring the emission of gases is difficult to achieve in industrial sites and in environments presenting poor infrastructures. Hence, robust methodologies should be developed and coupled to Lidar technology to allow remote sensing of gas emission. OSAS is a new methodology to evaluate gas concentration emission from spectrally integrated differential absorption measurements. Proof of concept of OSAS-Lidar for CH4 emission monitoring is here presented.

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Lauster, Bianca, Steffen Dörner, Steffen Beirle, Sebastian Donner, Sergey Gromov, Katharina Uhlmannsiek, and Thomas Wagner. "Estimating real driving emissions from multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements at the A60 motorway near Mainz, Germany." Atmospheric Measurement Techniques 14, no. 1 (February 1, 2021): 769–83. http://dx.doi.org/10.5194/amt-14-769-2021.

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Abstract. In urban areas, road traffic is a dominant source of nitrogen oxides (NOx=NO+NO2). Although the emissions from individual vehicles are regulated by the European emission standards, real driving emissions often exceed these limits. In this study, two multi-axis differential optical absorption spectroscopy (MAX-DOAS) instruments on opposite sides of the motorway were used to measure the NO2 absorption caused by road traffic at the A60 motorway close to Mainz, Germany. In combination with wind data, the total NOx emissions for the occurring traffic volume can be estimated. Hereto, the ozone-dependent photochemical equilibrium between NO and NO2 is considered. We show that for 10 May 2019 the measured emissions exceed the maximum expected emissions calculated from the European emission standards for standardised test cycles by a factor of 11±7. One major advantage of the method used here is that MAX-DOAS measurements are very sensitive to the integrated NO2 concentration close to the surface. Thus, all emitted NO2 molecules are detected independently from their altitude, and therefore the whole emission plume originating from the nearby motorway is captured, which is a key advantage compared to other approaches such as in situ measurements.

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Santos, Carla I. M., Inês F. A. Mariz, Sandra N. Pinto, Gil Gonçalves, Igor Bdikin, Paula A. A. P. Marques, Maria Graça P. M. S. Neves, José M. G. Martinho, and Ermelinda M. S. Maçôas. "Selective two-photon absorption in carbon dots: a piece of the photoluminescence emission puzzle." Nanoscale 10, no. 26 (2018): 12505–14. http://dx.doi.org/10.1039/c8nr03365j.

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Saturni, F. G., M. Bischetti, E. Piconcelli, A. Bongiorno, C. Cicone, C. Feruglio, F. Fiore, et al. "Restframe UV-to-optical spectroscopy of APM 08279+5255." Astronomy & Astrophysics 617 (September 2018): A118. http://dx.doi.org/10.1051/0004-6361/201832794.

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We present the analysis of the restframe optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at z = 3.911. The spectroscopic data were taken with the optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between C III] λ1910 and [O III] λλ4959,5007. We have investigated the possible presence of multiple BALs by computing “balnicity” and absorption indexes (i.e., BI, BI0, and AI) for the transitions Si IV λ1400, C IV λ1549, Al III λ1860, and Mg II λ2800. No clear evidence for the presence of absorption features is found in addition to the already known, prominent BAL associated to C IV, which supports a high-ionization BAL classification for APM 08279+5255. We also studied the properties of the [O III], Hβ, and Mg II emission lines. We find that [O III] is intrinsically weak (F[OIII]∕FHβ ≲ 0.04), as it is typically found in luminous quasars with a strongly blueshifted C IV emission line (~2500 km s−1 for APM 08279+5255). We computed the single-epoch black hole mass based on Mg II and Hβ broad emission lines, finding MBH = (2 ÷ 3) × 1010μ−1 M⊙, with the magnification factor μ that can vary between 4 and 100 according to CO and restframe UV-to-mid-IR imaging respectively. Using a Mg II equivalent width (EW)-to-Eddington ratio relation, the EWMgII ~ 27 Å measured for APM 08279+5255 translates into an Eddington ratio of ~0.4, which is more consistent with μ = 4. This magnification factor also provides a value of MBH that is consistent with recent reverberation-mapping measurements derived from C IV and Si IV.

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Viswanath, Ranganaik, Halehatty Seethya Bhojya Naik, Yashavanth Kumar Gubbihally Somalanaik, Prashanth Kumar Parlesed Neelanjeneallu, Khandugadahalli Nagarajappa Harish, and Mustur Channabasappa Prabhakara. "Studies on Characterization, Optical Absorption, and Photoluminescence of Yttrium Doped ZnS Nanoparticles." Journal of Nanotechnology 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/924797.

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Pure ZnS and ZnS:Y nanoparticles were synthesized by a chemical coprecipitation route using EDTA-ethylenediamine as a stabilizing agent. X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry (FTIR), thermogravimetric-differential scanning calorimetry (TG-DSC), and UV-visible and photoluminescence (PL) spectroscopy were employed to characterize the as-synthesized ZnS and ZnS:Y nanoparticles, respectively. XRD and TEM studies show the formation of cubic ZnS:Y particles with an average size of ~4.5 nm. The doping did not alter the phase of the zinc sulphide, as a result the sample showed cubic zincblende structure. The UV-visible spectra of ZnS and ZnS:Y nanoparticles showed a band gap energy value, 3.85 eV and 3.73 eV, which corresponds to a semiconductor material. A luminescence characteristics such as strong and stable visible-light emissions in the orange region alone with the blue emission peaks were observed for doped ZnS nanoparticles at room temperature. The PL intensity of orange emission peak was found to be increased with an increase in yttrium ions concentration by suppressing blue emission peaks. These results strongly propose that yttrium doped zinc sulphide nanoparticles form a new class of luminescent material.

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Banerjee, Gourav, Blesson Mathew, K. T. Paul, Annapurni Subramaniam, Suman Bhattacharyya, and R. Anusha. "Optical spectroscopy of Galactic field classical Be stars." Monthly Notices of the Royal Astronomical Society 500, no. 3 (November 10, 2020): 3926–43. http://dx.doi.org/10.1093/mnras/staa3469.

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ABSTRACT In this study, we analyse the emission lines of different species present in 118 Galactic field classical Be stars in the wavelength range of 3800–9000 Å. We re-estimated the extinction parameter (AV) for our sample stars using the newly available data from Gaia DR2 and suggest that it is important to consider AV while measuring the Balmer decrement (i.e. D34 and D54) values in classical Be stars. Subsequently, we estimated the Balmer decrement values for 105 program stars and found that ≈20 per cent of them show D34 ≥ 2.7, implying that their circumstellar disc are generally optically thick in nature. One program star, HD 60855 shows H α in absorption – indicative of disc-less phase. From our analysis, we found that in classical Be stars, H α emission equivalent width values are mostly lower than 40 Å, which agrees with that present in literature. Moreover, we noticed that a threshold value of ∼10 Å of H α emission equivalent width is necessary for Fe ii emission to become visible. We also observed that emission line equivalent widths of H α, P14, Fe ii 5169, and O i 8446 Å for our program stars tend to be more intense in earlier spectral types, peaking mostly near B1-B2. Furthermore, we explored various formation regions of Ca ii emission lines around the circumstellar disc of classical Be stars. We suggest the possibility that Ca ii triplet emission can originate either in the circumbinary disc or from the cooler outer regions of the disc, which might not be isothermal in nature.

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Tan, Ting Feng, Bian Peng Wu, Li Gang Bai, Yan Xia Li, and Ming Jie Zhang. "Synthesis and Optical Properties of Asymmetric Naphthylmethylene 1,3,4-Oxadiazole Derivatives." Advanced Materials Research 1033-1034 (October 2014): 1109–13. http://dx.doi.org/10.4028/www.scientific.net/amr.1033-1034.1109.

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Asymmetric 2-p-nitrophenyl-5-naphthylmethylene-1,3,4-oxadiazole and 2-p-aminophenyl-5-naphthylmethylene-1,3,4-oxadiazole were synthesized and characterized by IR、1HNMR and MS analysis, and their optical properties were detected using UV-vis absorption spectroscopy and fluorescence spectroscopy. The existence of electron-withdrawing oxadiazole units causes a significant bathochromic shift of the UV absorption maximum. The largest UV-absorption peak of target compounds is in the range of 298-317 nm, and a new emission band at 402 nm is formed. The fluorescence intensity is gradually enhanced, which strengthens the intramolecular charge transfer effect between the electron-withdrawing oxadiazole and electron-donating aniline.

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Sola, Daniel, Adrián Miguel, Eduardo Arias-Egido, and Jose I. Peña. "Spectroscopy and Near-Infrared to Visible Upconversion of Er3+ Ions in Aluminosilicate Glasses Manufactured with Controlled Optical Transmission." Applied Sciences 11, no. 3 (January 26, 2021): 1137. http://dx.doi.org/10.3390/app11031137.

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In this work we report on the spectroscopic properties and the near-infrared to visible upconversion of Er3+ ions in aluminosilicate glasses manufactured by directionally solidification with the laser floating zone technique. Glasses were manufactured in a controlled oxidizing atmosphere to provide them with high optical transmission in the visible spectral range. Absorption and emission spectra, and lifetimes were assessed in both the visible and the near infrared spectral range. Green upconversion emissions of the 2H11/2→4I15/2 and 4S3/2→4I15/2 transitions at 525 nm and 550 nm attributed to a two-photon process were observed under excitation at 800 nm. Mechanisms responsible for the upconversion luminescence were discussed in terms of excited state absorption and energy transfer upconversion processes. Excitation spectra of the upconverted emission suggest that energy transfer upconversion processes are responsible for the green upconversion luminescence.

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Wang, Zhiqiang, Xiaoxuan Guo, and Tsun-Kong Sham. "2D XANES-XEOL mapping: observation of enhanced band gap emission from ZnO nanowire arrays." Nanoscale 6, no. 12 (2014): 6531–36. http://dx.doi.org/10.1039/c4nr01049c.

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Using two-dimensional X-ray absorption near-edge structure-X-ray excited optical luminescence (2D XANES-XEOL) spectroscopy, it is found that the band gap emission of ZnO nanowire arrays is substantially enhancedi.e.that the intensity ratio between the band gap and defect emissions increases by more than an order of magnitude when the excitation energy is scanned across the O K-edge. Possible mechanisms are discussed.

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Paiano, Simona, Renato Falomo, Aldo Treves, and Riccardo Scarpa. "Optical spectroscopy of BL Lac objects: TeV candidates." Monthly Notices of the Royal Astronomical Society 497, no. 1 (June 27, 2020): 94–108. http://dx.doi.org/10.1093/mnras/staa1840.

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ABSTRACT We investigate the spectroscopic optical properties of gamma-ray sources detected with high significance above 50 GeV in the Third Catalog of Hard Fermi-LAT Sources and that are good candidates as TeV emitters. We focus on the 91 sources that are labelled by the Fermi team as BL Lac (BLL) objects or blazar candidates of uncertain type (BCUs), are in the Northern hemisphere, and are with unknown or uncertain redshift. We report here on GTC (Gran Telescopio Canarias) spectra (in the spectral range 4100–7750 Å) of 13 BCUs and 42 BLL objects. We are able to classify the observed targets as BLL objects and each source is briefly discussed. The spectra allowed us to determine the redshift of 25 objects on the basis of emission and/or absorption lines, finding 0.05 < z < 0.91. Most of the emission lines detected are due to forbidden transition of [O iii] and [N ii]. The observed line luminosity is found to be lower than that of quasi-stellar objects (QSOs) at similar continuum and could be reconciled with the line–continuum luminosity relationship of QSOs if a significant beaming factor is assumed. Moreover, for five sources we found intervening absorption lines that allow to set a spectroscopic lower limit of the redshift. For the remaining 25 sources, for which the spectra are lineless, a lower limit to z is given, assuming that the host galaxies are giant ellipticals.

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Ando, Kazuko, Naoya Fukuda, Hidehiko Akazawa, Bunei Sato, Ryo Hasegawa, Yohei Koizumi, Masashi Omiya, et al. "Optical spectroscopic monitoring of the symbiotic star MWC 560 before and after the 2018 unpredicted brightening." Publications of the Astronomical Society of Japan 73, no. 3 (March 25, 2021): L1—L5. http://dx.doi.org/10.1093/pasj/psab016.

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Abstract MWC 560 (V694 Mon) is classified as a symbiotic binary consisting of a white dwarf and an M5III red giant. In this object, a very- high-speed component, thought to be a jet, has been reported in the hydrogen Balmer line. We have been conducting long-term spectroscopic monitoring since the brightening in 2016 February. An irregular rebrightening was reported by Goranskij et al. (2018, Astronomer’s Telegram, 12227), who also showed that the high-velocity absorption component was not seen on 2018 November 16. Our low-resolution spectroscopic observations showed no high-velocity absorption component on 2018 November 14, and wide emission lines in Balmer line region (Hα, Hβ). However, high-resolution spectroscopy revealed the presence of slow, weak absorbing components and an emission wing on 2018 December 25. MWC 560 began to brighten in 2018 November, and it is gradually brightening as of 2020 April 14. For the absorption component, we propose a shell expansion of a classical symbiotic nova that occurred in 2016. During the 2018 brightening a new emission wing with vFWHM ≈ 700 km s−1 was confirmed, which could be triggered by disk instability like a dwarf nova. This paper summarizes the results of long-term monitoring observations and the recent changes in MWC 560.

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Chinchilla, P., V. J. S. Béjar, N. Lodieu, M. R. Zapatero Osorio, and B. Gauza. "Strong Hα emission in the young planetary mass companion 2MASS J0249−0557 c." Astronomy & Astrophysics 645 (December 22, 2020): A17. http://dx.doi.org/10.1051/0004-6361/202038731.

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Aims. Our objective is the optical and near-infrared spectroscopic characterisation of 2MASS J0249−0557 c, a recently discovered young planetary mass companion to the β Pictoris (~25 Myr) member 2MASS J0249−0557. Methods. Using the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey and the Two Micron All Sky Survey (2MASS) data, we independently identified the companion 2MASS J0249−0557 c. We also obtained low-resolution optical spectroscopy of this object using the Optical System for Imaging and low-intermediate-Resolution Integrated Spectroscopy spectrograph at the Gran Telescopio Canarias, and near-infrared spectroscopy using the Son of Isaac spectrograph on the New Technology Telescope. Results. We classified 2MASS J0249−0557 c with a spectral type of L2.5 ± 0.5 in the optical and L3 ± 1 in the near-infrared. We identified several spectroscopic indicators of youth both in the optical and in the near-infrared that are compatible with the age of the β Pictoris moving group: strong absorption due to oxides, weak alkaline atomic lines, and a triangular shape of the H-band pseudo-continuum. We also detect a strong Hα emission, with a pseudo-equivalent width (pEW) of −90−40+20 Å, which seems persistent at timescales from several days to a few years. This indicates strong chromospheric activity or disk accretion. Although many M-type brown dwarfs have strong Hα emission, this target is one of the very few L-type planetary mass objects in which this strong Hα emission has been detected. Lithium absorption at 6708 Å is observed with pEW ≲5 Å. We also computed the binding energy of 2MASS J0249−0557 c and obtained an (absolute) upper limit of U = (−8.8 ± 4.4) × 1032 J. Conclusions. Similarly to other young brown dwarfs and isolated planetary mass objects, strong Hα emission due to accretion or chromospheric activity is also present in young planetary mass companions at ages of some dozen million years. We also found that 2MASS J0249−0557 c is one of the wide substellar companions with the lowest binding energy known to date.

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Hutchings, J. B., and S. G. Neff. "Morphology and Spectroscopy of Markarian 231." Symposium - International Astronomical Union 121 (1987): 399–401. http://dx.doi.org/10.1017/s007418090015541x.

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Deep optical imaging of Mkn 231 reveals twin (tidal?) tails, a linear nuclear feature at green wavelengths, and a very blue region 4 arcsec south of the nucleus. Much of the central part of the galaxy is red, but there are complex areas of blue luminosity outside this, and a sharp edge to the luminosity at a distance of ~16 arcsec from the centre. Overall, the host galaxy appears to have a normal optical luminosity and blue colour (B-R ~0.7) despite being one of the most luminous galaxies known in the infrared. Radio emission in the system is extended on one side on a similar scale to the optical tails, but shows no detailed correspondence with optical structure; in particular there is no radio counterpart to the optical ‘jet’. Examination of IUE archival data indicate that the UV flux is very weak and the UV spectrum is peculiar for a Seyfert galaxy. The UV observations provide evidence for considerable nuclear extinction in the system, in accordance with previously published optical and infrared work, but the UV extinction is unlike Galactic absorption and may be more similar to that seen in the LMC. Recent optical spectra of Mkn 231 show changes in both the emission line spectrum and in the strong broad absorption lines (BAL), compared with previously published observations. This places strong limitations on the size of the nuclear continuum source. We suggest that Mkn 221 is a recently merged system which is currently undergoing star-formation, and discuss the connection with BAL QSOs.

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Zhai, Bao-gai, Long Yang, and Yuan Huang. "Intrinsic Defect Engineering in Eu3+ Doped ZnWO4 for Annealing Temperature Tunable Photoluminescence." Nanomaterials 9, no. 1 (January 15, 2019): 99. http://dx.doi.org/10.3390/nano9010099.

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Eu3+ doped ZnWO4 phosphors were synthesized via the co-precipitation technique followed by subsequent thermal annealing in the range of 400–1000 °C. The phase, morphology, elemental composition, chemical states, optical absorption, and photoluminescence (PL) of the phosphors were characterized by X-ray diffraction, scanning electron microscopy, dispersive X-ray spectroscopy, X-ray photoelectron spectrometry, diffuse UV–vis reflectance spectroscopy, PL spectrophotometry, and PL lifetime spectroscopy, respectively. It is found that the PL from Eu3+ doped ZnWO4 is tunable through the control of the annealing temperature. Density functional calculations and optical absorption confirm that thermal annealing created intrinsic defects in ZnWO4 lattices play a pivotal role in the color tunable emissions of the Eu3+ doped ZnWO4 phosphors. These data have demonstrated that intrinsic defect engineering in ZnWO4 lattice is an alternative and effective strategy for tuning the emission color of Eu3+ doped ZnWO4. This work shows how to harness the intrinsic defects in ZnWO4 for the preparation of color tunable light-emitting phosphors.

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Matsumoto, Fukashi, and Yoshiki Chujo. "Chiral π-conjugated organoboron polymers." Pure and Applied Chemistry 81, no. 3 (January 1, 2009): 433–37. http://dx.doi.org/10.1351/pac-con-08-08-01.

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A novel π-conjugated organoboron polymer with a chiral side chain was prepared by way of hydroboration polymerization between an optically active diyne monomer and triisopropylphenylborane. The achiral analog of this organoboron polymer was also prepared as reference material. Optical properties and optical activity were investigated by UV-vis absorption, fluorescence emission, and circular dichroism (CD) spectroscopy. Concentration dependence and the influence of solvent effects upon chiroptical activity are described.

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Duan, Jun Hong, Zhen Ya Xu, and Hao Feng. "The Growth and Optical Properties of CdS Nanorods via Solvent-Thermal Route." Advanced Materials Research 652-654 (January 2013): 647–53. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.647.

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CdS nanocrystals were synthesized by a solvent-thermal method in ethylenediamine at different temperature and time. The samples were investigated by XRD, TEM, Uv-vis absorption and PL spectroscopy. The solvent-thermal temperature at 200 °C is an optimal reaction temperature for preparing CdS nanorods with high crystallinity. The PL spectra exhibited two typical emissions: near band edge emission (centered at ~520nm) and defect emission (a broad peak in the range of 550-750nm). The defect emission decreased gradually and disappeared finally with the reaction time increasing from 1 to 12h, but the near band edge emission increased. This revealed that the quality of the CdS samples improved by degrees as the reaction time increased. The growth of single-crystalline CdS nanorods followed three steps; (a) CdS nuclei formed by reacting Cadmium chloride dihydrate and thiourea in ethylenediamine at 200 °C, (b) CdS nuclei grew into thin nanowhiskers after 1h reaction, (c) the growth of CdS nanorods based on nanowhiskers via a Ostwald ripening process.

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Archana, L. S., and Deepthi N. Rajendran. "Structural and Optical Properties of Ce3+ Doped ZnS Nanoparticles." Advanced Science Letters 24, no. 8 (August 1, 2018): 5994–99. http://dx.doi.org/10.1166/asl.2018.12233.

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ZnS nanoparticles doped with various concentration of Cerium were synthesized by solid state reaction method. The presence of Ce3+ ions in the synthesized samples were verified using X-ray powder diffraction and energy-dispersive X-ray spectrum. XRD analysis showed that sample prepared were hexagonal zinc sulphide with particles’ size in the ranges 36 nm–45 nm. The crystallite size of the particles increases with Ce3+ doping. UV-Vis absorption spectroscopy measurements have shown that the strongest absorption peak of nano ZnS is blue shifted compared to bulk ZnS. The strongest absorption peak of Ce3+ doped nano ZnS is red shifted with respect to parent nano ZnS. The existence of functional groups was identified using Fourier transform infrared spectrometer. The PL emission studies of Ce3+ doped ZnS revealed good emission at 422 nm and 459 nm when excited with wavelength 290 nm.

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Cao, Ping, and Yue Bai. "Structural and Optical Properties of Al Co-Doped ZnCoO Thin Film." Advanced Materials Research 989-994 (July 2014): 656–59. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.656.

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Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

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Humaida, Hanik. "SO₂ EMISSION MEASUREMENT BY DOAS (DIFFERENTIAL OPTICAL ABSORPTION SPECTROSCOPY) AND COSPEC (CORRELATION SPECTROSCOPY) AT MERAPI VOLCANO (INDONESIA)." Indonesian Journal of Chemistry 8, no. 2 (June 17, 2010): 151–57. http://dx.doi.org/10.22146/ijc.21617.

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The SO2 is one of the volcanic gases that can use as indicator of volcano activity. Commonly, SO2 emission is measured by COSPEC (Correlation Spectroscopy). This equipment has several disadvantages; such as heavy, big in size, difficulty in finding spare part, and expensive. DOAS (Differential Optical Absorption Spectroscopy) is a new method for SO2 emission measurement that has advantages compares to the COSPEC. Recently, this method has been developed. The SO2 gas emission measurement of Gunung Merapi by DOAS has been carried out at Kaliadem, and also by COSPEC method as comparation. The differences of the measurement result of both methods are not significant. However, the differences of minimum and maximum result of DOAS method are smaller than that of the COSPEC. It has range between 51 ton/day and 87 ton/day for DOAS and 87 ton/day and 201 ton/day for COSPEC. The measurement of SO2 gas emission evaluated with the seismicity data especially the rockfall showed the presence of the positive correlation. It may cause the gas pressure in the subsurface influencing instability of 2006 eruption lava. Keywords: SO2 gas, Merapi, DOAS, COSPEC

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Khan, Ziaul Raza, Anver Aziz, Mohd Shahid Khan, and M. U. Khandaker. "Influence of zinc concentration on band gap and sub-band gap absorption on ZnO nanocrystalline thin films sol-gel grown." Materials Science-Poland 35, no. 1 (February 24, 2017): 246–53. http://dx.doi.org/10.1515/msp-2017-0039.

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AbstractZnO thin films were fabricated on quartz substrates at different zinc acetate molar concentrations using sol-gel spin coating method. The samples were characterized using X-ray diffraction, field emission scanning electron microscope, UV-Vis spectroscopy, FT-IR spectroscopy and photoluminescence spectroscopy. Sub-band gap absorption of ZnO thin films in the forbidden energy region was carried out using highly sensitive photothermal deflection spectroscopy (PDS). The absorption coefficients of ZnO thin films increased in the range of 1.5 eV to 3.0 eV, upon increasing zinc concentration. The optical band gaps were evaluated using Tauc’s plots and found to be in the range of 3.31 eV to 3.18 eV. They showed the red shift in the band edge on increase in zinc concentration. The PL spectra of ZnO thin films revealed the characteristic band edge emission centered at the 396 nm along with green emission centered at the 521 nm.

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Dey, R. K., M. A. H. Chowdury, N. Chawdhury, and A. P. Monkman. "Report on Optical Absorption, Steady-state Emission and Time-resolved Emission Spectroscopy of Carbazole-based Conjugated Polymers." Journal of Scientific Research 3, no. 1 (December 17, 2010): 13. http://dx.doi.org/10.3329/jsr.v3i1.4666.

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Opto-electronic properties of three new carbazole based co-polymers were investigated. The decay kinetics of triplet emission of the co-polymers was observed. Several findings such as optical band-gap, singlet to singlet transition energies, triplet to singlet transition energies, exchange energies (?EST) have been presented. In comparison to the other material carbazole-oxadiazole based polymer with OMe, P1, H21C10, P2 and H12C10O, P3 exchange energy is below 0.5 eV and triplet energy is significantly higher. The energy gaps between singlet and triplet excited states are 0.44-0.47 eV. From decay kinetics the triplet excited state life-times were found to be several orders of ms at 10-13 K that reduces to less than 3 ms at room temperature.Keywords: Time resolved emission spectroscopy; Carbazole; Conjugated polymers.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i1.4666 J. Sci. Res. 3 (1), 13-24 (2011)

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Pandiyarajan, Thangaraj, and B. Karthikeyan. "Structural, Thermal and Optical Properties of PVP Capped ZnO Films." Advanced Materials Research 678 (March 2013): 253–57. http://dx.doi.org/10.4028/www.scientific.net/amr.678.253.

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In the present work we report, synthesis, structural, thermal and optical properties of ZnO incorporated PVP films. To prepare Polyvinylpyrolidone (PVP) capped ZnO films, simple room temperature sol gel method was adopted. Prepared PVP capped ZnO films were annealed at 800 C for 15 min and 30 min. X ray diffraction pattern shows prepared particles are in hexagonal wurtzite structure. Optical absorption measurements show an exciton absorption peak around ~ 370 nm. Emission spectra shows strong peaks around 329 and 333 nm are attributed to the band edge emission and broad peak found at 432 nm is attributed to the defect related emission. Thermal properties of the prepared films were studied by thermo gravimetric analysis. Interaction between the ZnO nanoparticles and PVP were investigated by Fourier Transform Infrared Spectroscopy (FTIR), it shows band at 441 cm-1 is attributed to Zn-O bond.

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Mennickent, Ronald E., Zbigniew Kołaczkowski, Gojko Djurasevic, M. Diaz, and Ewa Niemczura. "Optical Spectroscopy of V393 Scorpii During its Long Cycle." Proceedings of the International Astronomical Union 7, S282 (July 2011): 317–18. http://dx.doi.org/10.1017/s1743921311027694.

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AbstractV393 Scorpii is a bright Galactic Double Periodic Variable showing a long photometric cycle of ≈253 days. The ASAS V-band light curve has been disentangled into an orbital and long cycle component. The orbital light curve was modeled with two stellar components and a circumprimary accretion disk. Based on this model, and the careful choice of a template spectrum for the donor, the contribution of the donor to the line+continuum spectrum was removed at every orbital phase. The remaining residual spectra were analyzed. Notable findings are the larger line emissivity observed during the long cycle maximum that is concentrated to low velocities and the presence of discrete absorption components in the wings of the OI 7773 line, whose visibility strongly depends on the orbital phase. In addition, weak emission is observed in donor metallic absorption lines. Finally, we present the first Hα Doppler map for V 393 Scorpii. A modulated wind explains many observational features.

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Kafka, S., C. Tappert, R. K. Honeycutt, and A. Bianchini. "Time-Resolved Spectroscopy of Q CYG." International Astronomical Union Colloquium 194 (July 2004): 237. http://dx.doi.org/10.1017/s0252921100152820.

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A time-resolved optical spectroscopic study of the long-period (P=10.08h) old nova Q Cyg has revealed persistent yet erratic absorption features indicating the presence of a wind, while the system was rising to one of its stunded outbursts. Data taken with the WIYN 3.5m telescope show P Cygni profiles in the He I triplet lines at 5876Å and 7065Å, which are absent in the He I singlet emission line at 6678Å, despite the fact that the relevant energy levels of those three lines are at very similar excitation levels. The Hα line often has a red ward emission tail, characteristic of a receding outflow, and it possess a blueward absorption profile during only one wind event. Kafka et al. (2003) argued that this behavior is due to the strongly metastable 2 3S effective ground state of the He I triplets, which becomes over-populated in conditions of low density and a dilute radiation field, over-populating in turn the 23P common lower level of He I 5876Å and 7065Å, leading to absorption from a low density wind. Therefore, the triplet/singlet lines trace two different parts of the system: the wind and the disk respectively.

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Balsukuri, Naresh, Shigeki Mori, and Iti Gupta. "Donor acceptor type ferrocene substituted aza-BODIPYs: Synthesis, optical and electrochemical studies." Journal of Porphyrins and Phthalocyanines 20, no. 06 (June 2016): 719–29. http://dx.doi.org/10.1142/s1088424616500693.

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Two ferrocene substituted aza-BODIPYs and their corresponding aza-dipyrrins were synthesized and studied. All the compounds were characterized by HRMS, NMR, IR, absorption spectroscopy and cyclic voltammetry techniques. Absorption spectra indicated intramolecular electron transfer from the ferrocene to the aza-BODIPY core. The X-ray crystal structure of 1,7-bisferrocenyl-aza-BODIPY suggested moderate interactions between the ferrocene moieties and aza-BODIPYs core. Ferrocenyl-aza-BODIPYs were non-emissive due to electron transfer from ferrocene moieties to boron aza-dipyrrin core. However the emission of these compounds was dramatically enhanced by oxidizing the ferrocene moieties to ferrocenium ions, which prevents electron transfer between these moieties. Cyclic voltammetry studies suggested that aza-BODIPYs were easier to be reduced as compared to their corresponding aza-dipyrrins.

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Agrawalla, Rajesh K., Rima Paul, Amit K. Chakraborty, and Apurba K. Mitra. "Synthesis and Optical Characterization of Sulfonated Polyaniline/Single-Walled Carbon Nanotube/Zinc Sulphide Nanocomposite." ISRN Nanotechnology 2013 (November 4, 2013): 1–6. http://dx.doi.org/10.1155/2013/253016.

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Polyaniline functionalized with sulfonate groups (SPANI) shows excellent solubility in water. Single-walled carbon nanotubes functionalized with carboxylic groups (f-SWCNTs) and then hybridized with freshly prepared zinc sulphide (ZnS) nanocrystals have been found to be good luminescent material with tuned emission properties. Nanocomposite of sulfonated polyaniline with embedded SWCNT/ZnS nanohybrid fibers has been prepared by a simple solution mixing process and characterized by using high resolution transmission electron microscopy (HRTEM), X-ray diffractometry, Raman spectroscopy, FTIR spectroscopy, and thermogravimetric analysis (TGA). The study of optical properties by UV-vis absorption and photoluminescence spectroscopy reveals that the composite is a luminescent material of enhanced emission intensity in the visible region of the spectrum.

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Hickson, Paul, and J. B. Hutchings. "Resolved imaging and spectroscopy of QSOs." Symposium - International Astronomical Union 119 (1986): 117–19. http://dx.doi.org/10.1017/s0074180900152428.

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We have obtained direct images and off-nuclear spectra for five QSOs having a wide range of radio, optical and X-ray luminosity. Four objects show absorption features identified with stars in a host galaxy, and off-nuclear changes in emission line wavelengths. All objects show off-nuclear changes in continuum coulour, and in emission line intensities and ratios. The radio loud objects have more luminous galaxies, strong and extended [OII] and [OIII], and UV-bright nuclei. They tend to have luminous nuclei, high nuclear to galaxy luminosity ratio, and blue host galaxies. This paper is a brief summary of results that will appear in more detail elsewhere.

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Methling, R., St Franke, N. Götte, S. Wetzeler, and D. Uhrlandt. "Analysis of C2 Swan Bands in Ablation-Dominated Arcs in CO2 Atmosphere." PLASMA PHYSICS AND TECHNOLOGY 6, no. 1 (2019): 82–86. http://dx.doi.org/10.14311/ppt.2019.1.82.

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A model circuit breaker in a high-pressure chamber filled with CO2 atmosphere is used to operate a wall-stabilized arc of several kilo-amperes between tungsten-copper electrodes surrounded by polytetrafluoroethylene nozzles. Optical emission spectroscopy (OES) is carried out via quartz plates inserted into the nozzles using a combination of an imaging spectrometer either with a high-speed video camera or with an ICCD camera. Depending on the nozzle geometry and the current, continuum from C2 Swan bands was detected as absorption as well as emission pattern. After current zero, optical absorption spectroscopy (OAS) using a xenon flashlamp as broadband background radiator was applied. An absorption around 493 nm was detected and attributed to CuF molecules. The study proofs the existence of C2 in the active phase and the formation of CuF near to current zero.

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Deshpande, M. P., Kiran N. Patel, Vivek P. Gujarati, Kamakshi Patel, and S. H. Chaki. "Structural, Thermal and Optical Properties of Nickel Oxide (NiO) Nanoparticles Synthesized by Chemical Precipitation Method." Advanced Materials Research 1141 (August 2016): 65–71. http://dx.doi.org/10.4028/www.scientific.net/amr.1141.65.

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Nanocrystalline NiO has been prepared successfully by chemical precipitation route using nickel nitrate hexahydrate (Ni (NO3)2·6H2O) and sodium hydroxide (NaOH) aqueous solution at a temperature of 60 ̊C. Their compositional, structural, morphological, thermal and optical properties were studied using energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectroscopy and Raman spectroscopy. From XRD pattern we confirmed the face centered cubic (fcc) structure of the synthesized NiO nanoparticles. The selected area electron diffraction (SAED) pattern indicated the same crystalline planes as seen in XRD pattern. TGA indicates good thermal stability of synthesized NiO nanoparticles and the optical absorption spectrum of NiO nanoparticles shows the strong absorption edge at 235nm (4.10eV). PL spectra of NiO nanoparticles shows two wide emission peaks at 420nm (2.95eV) and 440nm (2.82eV) and a strong–broad peak at 460nm (2.70eV) in violet emission band whereas the Raman peak observed at 518cm-1 shows the Ni-O stretching mode of vibration.

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GUO, SHENG-LI, ZHUN GUO, T. SUSDORF, and TIAN-DE CAO. "ABSORPTION, EMISSION AND NONLINEAR SPECTROSCOPIC CHARACTERIZATION OF REACTIVE DYE." Journal of Nonlinear Optical Physics & Materials 15, no. 04 (December 2006): 481–90. http://dx.doi.org/10.1142/s0218863506003414.

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An optical spectroscopic characterization is carried out on a reactive dye (reactive orange 1). This dye is widely applied in textile coloration. It is a potential candidate for photonics applications. Its absorption cross-section spectra are measured. A fluorescence spectroscopic characterization is undertaken by measuring the fluorescence quantum distributions and fluorescence quantum yields. The saturable absorption is studied by nonlinear transmission measurements with intense picosecond laser pulses (second harmonic pulses of a mode-locked Nd :glass laser). The nonlinear optical absorption and refraction coefficients are measured by using the top-hat Z-scan technique at a wavelength of 532 nm with 35 ps duration pulses. Reactive orange 1 has the two-photon absorption coefficient of 1.20 cm/GW and the nonlinear refraction coefficient of -7.33 × 10-6 cm2/GW, respectively. In reactive orange 1, there occurs fast ground-state recovery by internal conversion likely via conical intersections. Low excited-state absorption and fast ground-state absorption recovery make it an ideal candidate for passive mode-locking of picosecond and femtosecond lasers as well as for fast nonlinear optical gating.

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Lu, Huihui, Francesco Floris, Marc Rensing, and Stefan Andersson-Engels. "Fluorescence Spectroscopy Study of Protoporphyrin IX in Optical Tissue Simulating Liquid Phantoms." Materials 13, no. 9 (May 2, 2020): 2105. http://dx.doi.org/10.3390/ma13092105.

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Fluorescence spectroscopy has been extensively investigated for disease diagnosis. In this framework, optical tissue phantoms are widely used for validating the biomedical device system in a laboratory environment outside of clinical procedures. Moreover, it is fundamental to consider that there are several scattering components and chromophores inside biological tissues and the interplay between scattering and absorption may result in a distortion of the emitted fluorescent signal. In this work, the photophysical behaviour of a set of liquid, tissue-like phantoms containing different compositions was analysed: phosphate buffer saline (PBS) was used as the background medium, low fat milk as a scatterer, Indian ink as an absorber and protoporphyrin IX (PpIX) dissolved in dimethyl formamide (DMF) as a fluorophore. We examined the collected data in terms of the impact of surfactant Tween-20 on the background medium, scattering effects and combination of scattering and absorption within a luminescent body on PpIX. The results indicated that the intrinsic emission peaks are red shifted by the scattering particles or surfactant, whilst the scattering agent and the absorbent can alter the emission intensity substantially. We corroborated that phantoms containing higher surfactant content (>0.5% Tween 20) are essential to prepare stable aqueous phantoms.

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da Rocha-Poppe, P. C., V. A. Fernandes-Martin, M. Faúndez-Abans, M. de Oliveira-Abans, G. A. Silva, P. Freitas-Lemes, and C. Lima-Dias. "Optical long-slit spectroscopy in the cluster Abell S0805." Monthly Notices of the Royal Astronomical Society 488, no. 3 (July 5, 2019): 3685–715. http://dx.doi.org/10.1093/mnras/stz1833.

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ABSTRACT This contribution aims to study the nature (kinematic, nuclear activity, and stellar population) of a sample of 10 galaxies in the poor cluster Abell S0805. As no detailed optical spectroscopy for some members has been published yet, the selected sample makes this study ideal for investigating the properties of the following objects: ESO 104- G(002, 006, 007, 008, 009, 010, 013), Fairall 0187, and PGC (062384, 062391). Our main results were obtained after subtraction of the underlying stellar population with the spectral synthesis code starlight. The residual spectra reveal seven galaxies with only absorption lines [ESO 104- G(002, 007, 008, 009), Fairall 0187 and PGC (062384, 062391)], and three galaxies with emission lines [ESO 104- G(006, 010, 013)]. According to the boundaries in the diagnostic diagrams, the intensities of H α and the low-ionization lines ([N ii] λ6584 Å and [S ii] λλ6716,6731 Å) suggest the following results: (i) the brightest cluster galaxy (ESO 104- G006, an elliptical cD galaxy) shows low-ionization nuclear emission-line region (LINER)-like excitation, quite common in ‘cool core clusters’; (ii) the ESO 104- G010 (‘X-Galaxy’ or ‘Crystal Frog’) shows an excess of the nitrogen emission-line [N ii] λ6584 Å not yet reported. We also suggest this object as a LINER; (iii) the spiral ESO 104- G013 is a star-forming galaxy with typical emission lines. No obvious signs of interaction were observed in this study. The heliocentric velocities agree within 1σ with the most recent values. The stellar population, rotation curves, and velocity dispersions are also discussed for the first time for some objects.

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Darma, Yudi, and Andrivo Rusydi. "Optical Band Transitions and Excitonic States in ZnO:Cu Films." Advanced Materials Research 1112 (July 2015): 3–6. http://dx.doi.org/10.4028/www.scientific.net/amr.1112.3.

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Photoluminescence (PL), ultraviolet-visible (UV-VIS) absorption spectroscopy and spectroscopic ellipsometry (SE) are combining to study the optical transitions and electronic structures of Cu doped ZnO films with Cu concentration of 0, 2 and 8 at. %. By increasing Cu concentration, PL spectra show the enhancement of optical transition through the significantly increase of the green emission. Correspondingly, the in-plane UV visible absorption spectra show the redshift of first interband transition as the evidence of ZnO film become less insulating. More interestingly, extracted optical properties such asnandkclearly shows the mid-gap optical states, interband transitions and excitons. The excitonic peak decrease by increasing Cu concentration accompanied by a new broad structure assigned as a mid-gap state located under the conduction band area. Excitonic states are screened as decreasing its intensities by increasing Cu doping. Our results are beneficial to define interband transition and explain the mid-gap state in the oxide based semiconductor.

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Gaillard, M., N. Britun, Yong M. Kim, and Jeon G. Han. "Titanium density analysed by optical absorption and emission spectroscopy in a dc magnetron discharge." Journal of Physics D: Applied Physics 40, no. 3 (January 19, 2007): 809–17. http://dx.doi.org/10.1088/0022-3727/40/3/018.

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Jentschke, H., U. Schumacher, and K. Hirsch. "Studies of Silicon Erosion in Plasma-Target-Interaction from Optical Emission and Absorption Spectroscopy." Contributions to Plasma Physics 38, no. 4 (1998): 501–12. http://dx.doi.org/10.1002/ctpp.2150380404.

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Wang, Ru-Wen, Pin-Hua Xie, Jin Xu, and Ang Li. "Novel infrared differential optical absorption spectroscopy remote sensing system to measure carbon dioxide emission." Chinese Physics B 28, no. 1 (January 2019): 013301. http://dx.doi.org/10.1088/1674-1056/28/1/013301.

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Pommeret, Stanislas, Thomas Gustavsson, Ryszard Naskrecki, Gérard Baldacchino, and Jean-Claude Mialocq. "Femtosecond absorption and emission spectroscopy of the DCM laser dye." Journal of Molecular Liquids 64, no. 1-2 (August 1995): 101–12. http://dx.doi.org/10.1016/0167-7322(95)92824-u.

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Mikhail, Patric, Reto Basler, and Jürg Hulliger. "Czochralski growth and spectroscopic investigations of Yb3+, La3+:Na2SO4(I) and Nd3+:Na2SO4(I)." Journal of Materials Research 14, no. 10 (October 1999): 4093–97. http://dx.doi.org/10.1557/jmr.1999.0552.

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Ln3+-stabilized Na2SO4 (phase I) single crystals were grown by the Czochralski method. Differential thermal analysis revealed the influence of the ionic radius of Ln3+ on the stabilization of Na2SO4(I). Distribution coefficients (∼0.8–1.1) were measured by the inductively coupled plasma optical emission spectroscopy method and x-ray fluorescence spectroscopy. Spectroscopic investigations yielded absorption cross sections of 0.6 × 10−20 cm2 (π-polarized, 928.5 nm) and 1.5 × 10−20 cm2 (π-polarized, 797.3 nm) for Yb3+, La3+:Na2SO4 and Nd3+:Na2SO4, respectively. Crystal growth of Gd3+-stabilized Na2SO4(I) provides an interesting new material for stimulated Raman scattering experiments.

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Journal articles on the topic 'Optical emission and absorption spectroscopy'

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