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相关论文: Mg II Selected Absorbers: Ionization structures an…

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We examine the properties of two galaxy "halos" at z ~ 0.7 in the TON 153 (z_em = 1.01) quasar field. The first absorber-galaxy pair (G1) is a z = 0.672, L_B = 4.3 L*_B, E/S0 galaxy probed at D = 58 kpc. G1 is associated with a remarkable…

天体物理学 · 物理学 2011-02-11 Christopher W. Churchill , Glenn G. Kacprzak , Charles C. Steidel , Jessica L. Evans

Measuring rest-frame ultraviolet rotational transitions from the Lyman and Werner bands in absorption against a bright background continuum is one of the few ways to directly measure molecular hydrogen (H2). Here we report the detection of…

We present observations of the O VI system at z_abs = 0.495096 toward PKS 0405-123 (z_em = 0.5726) obtained with FUSE and STIS. In addition to strong O VI, with log N(O VI) = 14.47+/-0.02, and moderate H I this absorber shows C III, N IV, O…

宇宙学与河外天体物理 · 物理学 2009-03-25 J. Christopher Howk , Joseph S. Ribaudo , Nicolas Lehner , J. Xavier Prochaska , Hsiao-Wen Chen

We explore the circumgalactic metal content traced by commonly observed low ion absorbers, including C II, Si II, Si III, Si IV, and Mg II. We use a set of cosmological hydrodynamical zoom simulations run with the EAGLE model and including…

星系天体物理 · 物理学 2018-08-29 Benjamin D. Oppenheimer , Joop Schaye , Robert A. Crain , Jessica K. Werk , Alexander J. Richings

We present a survey of MgII absorbing gas in the vicinity of 380 random galaxies, using 156 background quasi-stellar objects(QSOs) as absorption-line probes. The sample comprises 211 isolated (73 quiescent and 138 star-forming galaxies) and…

The interstellar medium (ISM) consists of highly ionized and neutral atomic, as well as molecular, components. Knowledge of their distribution is important for tracing the structure and lifecycle of the ISM. Here we determine the properties…

星系天体物理 · 物理学 2016-05-25 W. D. Langer , P. F. Goldsmith , J. L. Pineda

The physical origin of the large-scale conformity in the colours and specific star formation rates of isolated low mass central galaxies and their neighbours on scales in excess of 1 Mpc is still under debate. One possible scenario is that…

星系天体物理 · 物理学 2018-02-14 Guinevere Kauffmann

We investigate the effect of two important, but oft neglected, factors which can affect the detectability of HI 21-cm absorption in MgII absorption systems: The effect of line-of-sight geometry of the coverage of the background radio flux…

宇宙学与河外天体物理 · 物理学 2015-05-14 S. J. Curran

Damped Lyman-alpha absorbers (DLAs), seen in absorption against a background quasar, provide the most detailed probes available of element abundances in the Universe over > 90 % of its age. DLAs can be used to observationally measure the…

天体物理学 · 物理学 2009-11-11 C. Peroux , J. D. Meiring , V. P. Kulkarni , R. Ferlet , P. Khare , J. T. Lauroesch , G. Vladilo , D. G. York

We present a study of the cool gas ($\approx 10^4$ K) traced by MgII absorptions around groups of galaxies in the MEGAFLOW survey. Using a combination of two algorithms we blindly identify 32 groups of more than 5 galaxies at $0.3 < z <…

The bimodal absorption system imaging campaign (BASIC) aims to characterize the galaxy environments of a sample of 36 HI-selected partial Lyman limit systems (pLLSs) and Lyman limit systems (LLSs) in 23 QSO fields at $z \lesssim 1$. These…

We have serendipitously detected a strong O VI-bearing Lyman limit system at z_abs = 0.3558 toward the QSO J1009+0713 (z_em = 0.456) in our survey of low-redshift galaxy halos with the Hubble Space Telescope's Cosmic Origins Spectrograph.…

宇宙学与河外天体物理 · 物理学 2015-05-27 J. Tumlinson , J. K. Werk , C. Thom , J. D. Meiring , J. X. Prochaska , T. M. Tripp , J. M. O'Meara , M. Okrochkov , K. R. Sembach

We estimate the He II to H I column density ratio, \eta = N(He II)/N(H I), in the intergalactic medium towards the high redshift (z_{em} = 2.885) bright quasar QSO HE 2347-4342 using Voigt-profile fitting of the H I transitions in the Lyman…

宇宙学与河外天体物理 · 物理学 2015-05-19 Sowgat Muzahid , Raghunathan Srianand , Patrick Petitjean

The Mg II 2796,2803 doublet is often used to measure interstellar medium absorption in galaxies, thereby serving as a diagnostic for feedback and outflows. However, the interpretation of Mg II remains confusing, due to resonant trapping and…

星系天体物理 · 物理学 2018-03-29 Alaina Henry , Danielle Berg , Claudia Scarlata , Anne Verhamme , Dawn Erb

We test whether the Tinker & Chen model of MgII absorption due to the gaseous halo around a galaxy can reproduce absorption in quasar pairs (both lensed and physical) and lensed triples and quads from the literature. These quasars exhibit…

宇宙学与河外天体物理 · 物理学 2015-03-19 Jesse A. Rogerson , Patrick B. Hall

Using the SDSS spectra of quasars included in the DR7Q or DR12Q catalogs, we search for Mg II narrow absorption doublets in the spectra data around Mg II emission lines. We obtain 17,316 Mg II doublets, within the redshift range of 0.3299<=…

星系天体物理 · 物理学 2018-01-25 Chen Zhi-Fu , Huang Wei-Rong , Pang Ting-Ting , Huang Hong-Yan , Pan Da-Sheng , Yao Min , Nong Wei-Jing , Lu Mei-Mei

Ca II absorbers, characterized by dusty and metal-rich environments, provide unique insights into the interstellar medium of galaxies. However, their rarity and weak absorption features have hindered comprehensive studies. In this work, we…

星系天体物理 · 物理学 2025-10-17 Lucas Wang , Jian Ge , Kevin Willis

Metal absorption systems are products of star formation. They are believed to be associated with massive star forming galaxies, which have significantly enriched their surroundings. To test this idea with high column density CIV absorption…

We report results from a survey of MgII absorbers in the spectra of background QSOs that are within close angular distances to a foreground galaxy at z<0.5, using the Magellan Echellette Spectrograph. We have established a spectroscopic…

宇宙学与河外天体物理 · 物理学 2015-05-18 Hsiao-Wen Chen , Jennifer E. Helsby , Jean-Rene Gauthier , Stephen A. Shectman , Ian B. Thompson , Jeremy L. Tinker

We report the first comparative study of strong MgII absorbers seen towards radio-loud quasars of core-dominated (CDQs) and lobe-dominated (LDQs) types and normal QSOs. The MgII associated absorption systems having a velocity offset v <…

宇宙学与河外天体物理 · 物理学 2015-06-16 Ravi Joshi , Hum Chand , Gopal-Krishna