Dissertations / Theses on the topic 'Quasar absorption lines'
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Crighton, Neil Physics Faculty of Science UNSW. "Cosmology with Quasar Absorption Lines." Awarded by:University of New South Wales. Physics, 2006. http://handle.unsw.edu.au/1959.4/30178.
Full textWebb, J. K. "QSO absorption lines." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234000.
Full textMurphy, Michael T. Physics Faculty of Science UNSW. "Probing variations in the fundamental constants with quasar absorption lines." Awarded by:University of New South Wales. School of Physics, 2002. http://handle.unsw.edu.au/1959.4/19062.
Full textBECHTOLD, JILL ELEANOR. "HIGH RESOLUTION SPECTROSCOPY OF QUASAR ABSORPTION LINES (INTERGALACTIC MEDIUM, EXTRAGALACTIC, GALAXIES)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188085.
Full textMorrison, Sean Stephen. "Using quasar absorption to study inhomogeneities in the UV background." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0501.
Full textThe study of the background radiation in the UV band is important for understanding the evolution of the Universe. The UV background (UVB) evolves and is inhomogeneous. It arises by virtue of quasars and star-forming galaxies, modifies the matter of the Universe by ionizing and heating gas. The focus of this thesis is the study of large-scale inhomogeneities in the extragalactic UVB and the modifications of metals by quasar proximity. We begin with the exploration of the dominant scales of inhomogeneities in the UVB by combining intergalactic absorption by hydrogen, helium (HeII), and oxygen in 2 quasar lines-of-sight. This combination was studied on various filtering scales and by comparing the lines-of-sight. It revealed inhomogeneities on scales of ~10cMpc and \gtrsim 200cMpc at \bar{z}\approx 2.6. This analysis was also applied to the HeII Gunn-Peterson trough, which showed no evidence of HeII reionization when compared to HeII forest data. We continue with an exploration of the direct relationship of quasars and metal ionization, by grouping intergalactic medium (IGM) absorbers by their proximity to their closest quasars in SDSS-IV/eBOSS. While this shows sensitivity to large-scale 3D quasar proximity, the current incomplete quasar samples limit detailed interpretation. It does demonstrate that the quasar contribution to the UVB can be explored by examining the metal absorption in the IGM. Finally, we discuss my contributions towards a complete quasar sample through validating the WEAVE reduction pipeline, as well assessing the expected quasar population and spectral quality. We close by discussing the potential impact of this sample on our analysis
Pieri, Matthew Michael. "Probing the metal enrichment of the intergalactic medium with quasar absorption lines." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416065.
Full textZou, Siwei. "Using quasar absorption lines to probe cold gas in high redshift galaxies." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS181/document.
Full textQuasar absorption lines are a powerful tool to study the interstellar medium(ISM) in the galaxies. We study a sample of 66 z >1.5 absorbers selected based on the presence of strong CI absorption lines in SDSS spectra and observed with the ESO-VLT spectrograph X-shooter/UVES. I study 17 systems that are re-observed by X-shooter. I derive metallicities, depletion onto dust, extinction by dust and analyse the absorption from MgII, MgI, CaII and NaI that are redshifted into the near infrared wavelength range. I detect 9 CaII absorptions with W(CaII λ3934) > 0.23 Å out of 14 systems. I detect 10 NaI absorptions in the 11 systems where we could observe this absorption. The median equivalent width (W(NaI λ5891) = 0.68 Å) is larger than what is observed in local clouds with similar HI column densities but also in z<0.7 CaII systems detected in the SDSS. The systematic presence of NaI absorption in these CI systems strongly suggests that the gas is neutral and cold, maybe part of the diffuse molecular gas in the ISM of high-redshift galaxies. The MgII absorptions are spread over more than Δv ~ 400 km/s for half of the systems; three absorbers have Δv > 500 km/s. The kinematics is strongly perturbed for most of these systems which probably do not arise in quiet disks and must be close to regions with intense star formation activity. All this suggests that a large fraction of the cold gas at high redshift arises in disturbed environments. We detect molecular hydrogen in all the systems within the detection limit
Xu, Xinfeng. "How Do Quasars Impact Their Host Galaxies? From the Studies of Quasar Outflows in Absorption and Emission." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98572.
Full textDoctor of Philosophy
Super massive black holes (SMBHs) are believed to exist in the center of almost all massive galaxies, where the brightest accreting ones are named ``quasars''. ``Quasar-mode feedback'' occurs when momentum and energy from the environment of accreting SMBHs couple to the host galaxy. One mechanism for such a coupling is by high-velocity (up to $sim$ 0.2c) quasar-driven ionized outflows, appearing as blue-shifted absorption and emission lines in quasar spectra. Given enough energy and momentum, these outflows are capable of affecting the evolution of their host galaxies. Such quasar outflows are invoked to explain a variety of observations, e.g., the chemical enrichment of the intergalactic medium (IGM), the shape of the observed quasar luminosity function, and the self-regulation of the growth of the SMBHs. In this dissertation, I focus on studying the emission and absorption outflows observed in quasars spectra, collected with the largest telescopes and most powerful instruments in the world. (1). By conducting large broad absorption line (BAL) quasar surveys in both Sloan Digital Sky Survey and Very Large Telescopes (VLT), we determined various physics properties of quasar absorption outflows, e.g., the electron number density (ne), the distance of outflows to the central quasar ($R$), and the kinetic energy carried by the outflow ($dot{E}_{k}$). We demonstrated that half of the typical BAL outflows are situated at $R$ $>$ 100 pc, i.e., having the potential to affect the host galaxies. (2). Our group carried out a Hubble Space Telescope program (PI: Arav) for studying the outflows in the Extreme-UV, collaborating with Dr. Gerard Kriss from Space Telescope Science Institute (STScI). We developed a novel method to fit the multitude of quasar absorption troughs efficiently and accurately. We have identified the most energetic quasar-driven outflows on record and discovered the largest acceleration and velocity-shift for a quasar absorption outflow. (3). By using the VLT data, Xu led the project to study the relationships between BAL outflows and emission line outflows. We found possible connections between these two types of quasar outflows, e.g., the luminosity of the [oiii] ly 5007 emission profile decreases with increasing ne derived from the BAL outflow in the same quasar. These findings are consistent with BAL and emission outflows being different manifestations of the same wind, and the observed relationships are likely a reflection of the outflow density distribution.
Krogager, J. K., J. P. U. Fynbo, K. E. Heintz, S. Geier, C. Ledoux, P. Møller, P. Noterdaeme, B. P. Venemans, and M. Vestergaard. "THE EXTENDED HIGH A(V) QUASAR SURVEY: SEARCHING FOR DUSTY ABSORBERS TOWARD MID-INFRARED-SELECTED QUASARS." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/624064.
Full textLiu, Wen-Juan, Hong-Yan Zhou, Ning Jiang, Xufen Wu, Jianwei Lyu, Xiheng Shi, Xinwen Shu, et al. "SDSS J163459.82+204936.0: A RINGED INFRARED-LUMINOUS QUASAR WITH OUTFLOWS IN BOTH ABSORPTION AND EMISSION LINES." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621240.
Full textPerrotta, S., V. D'Odorico, J. X. Prochaska, S. Cristiani, G. Cupani, S. Ellison, S. López, et al. "Nature and statistical properties of quasar associated absorption systems in the XQ-100 Legacy Survey." OXFORD UNIV PRESS, 2016. http://hdl.handle.net/10150/621733.
Full textOppenheimer, Benjamin Darwin. "The History of Enrichment of the Intergalactic Medium Using Cosmological Simulations." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194237.
Full textFord, Amanda Brady. "Understanding the Circumgalactic Medium Through Hydrodynamic Simulations and Hubble's Cosmic Origins Spectrograph." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/332661.
Full textMcGraw, Sean Michael. "Outflow and Accretion Physics in Active Galactic Nuclei." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1469701247.
Full textFu, Hai, J. F. Hennawi, J. X. Prochaska, R. Mutel, C. Casey, A. Cooray, D. Kereš, et al. "THE CIRCUMGALACTIC MEDIUM OF SUBMILLIMETER GALAXIES. I. FIRST RESULTS FROM A RADIO-IDENTIFIED SAMPLE." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/623949.
Full textMudd, Dale Montaine. "Understanding Supermassive Black Holes Using the Dark Energy Survey and OzDES." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500305577021114.
Full textYi, Weimin, Richard Green, Jin-Ming Bai, Tinggui Wang, Catherine J. Grier, Jonathan R. Trump, William N. Brandt, et al. "The Physical Constraints on a New LoBAL QSO at z = 4.82." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623841.
Full textDunn, Jay Patrick. "Intrinsic Absorption with the Far Ultraviolet Spectroscopic Explorer." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/phy_astr_diss/21.
Full textCai, Zheng, Xiaohui Fan, Sebastien Peirani, Fuyan Bian, Brenda Frye, Ian McGreer, J. Xavier Prochaska, et al. "MAPPING THE MOST MASSIVE OVERDENSITY THROUGH HYDROGEN (MAMMOTH). I. METHODOLOGY." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622671.
Full textChristensen, L., S. D. Vergani, S. Schulze, N. Annau, J. Selsing, J. P. U. Fynbo, Ugarte Postigo A. de, et al. "Solving the conundrum of intervening strong Mg II absorbers towards gamma-ray bursts and quasars." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/626409.
Full textBowen, David V., Doron Chelouche, Edward B. Jenkins, Todd M. Tripp, Max Pettini, Donald G. York, and Brenda L. Frye. "THE STRUCTURE OF THE CIRCUMGALACTIC MEDIUM OF GALAXIES: COOL ACCRETION INFLOW AROUND NGC 1097." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621229.
Full textKollmeier, Juna Ariele. "The intergalactic medium absorption, emission, disruption /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1153856075.
Full textZahedy, Fakhri S., Hsiao-Wen Chen, Michael Rauch, and Ann Zabludoff. "HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625809.
Full textBurchett, Joseph N., Todd M. Tripp, Rongmon Bordoloi, Jessica K. Werk, J. Xavier Prochaska, Jason Tumlinson, C. N. A. Willmer, John O’Meara, and Neal Katz. "A DEEP SEARCH FOR FAINT GALAXIES ASSOCIATED WITH VERY LOW REDSHIFT C iv ABSORBERS. III. THE MASS- AND ENVIRONMENT-DEPENDENT CIRCUMGALACTIC MEDIUM." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622446.
Full textZahedy, Fakhri S., Hsiao-Wen Chen, Michael Rauch, Michelle L. Wilson, and Ann Zabludoff. "Probing the cool interstellar and circumgalactic gas of three massive lensing galaxies at z = 0.4–0.7." OXFORD UNIV PRESS, 2016. http://hdl.handle.net/10150/614764.
Full textBoissé, Patrick. "Systemes de raies d'absorption des quasars. Transfert de rayonnement dans un milieu inhomogene." Paris 7, 1987. http://www.theses.fr/1987PA077095.
Full textBerg, Trystyn Andrew Munro. "Probing galaxy evolution with quasar absorption lines." Thesis, 2018. https://dspace.library.uvic.ca//handle/1828/9612.
Full textGraduate
Murphy, Michael T. "Probing variations in the fundamental constants with quasar absorption lines /." 2002. http://www.library.unsw.edu.au/~thesis/adt-NUN/public/adt-NUN20030919.083142/index.html.
Full textYork, Brian A. "The search for diffuse interstellar bands in quasar absorption line systems." Thesis, 2008. http://hdl.handle.net/1828/1074.
Full textRichards, Gordon Todd. "Intrinsic absorption lines in radio-selected quasars /." 2000. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9965146.
Full textBerg, Trystyn Andrew Munro. "Metal Strong Damped Lyman Alpha Systems And Their Context With The Local Group." Thesis, 2014. http://hdl.handle.net/1828/5308.
Full textGraduate
0606
Tepper-García, Thorsten. "The Stochastic Intergalactic Attenution and its Impact on High-Redshift Galaxies." Doctoral thesis, 2007. http://hdl.handle.net/11858/00-1735-0000-0006-B462-A.
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