A Candidate for an Intrinsic Dusty Absorber with a Metal-rich Damped Lyα Absorption Line System in the Quasar J170542.91+354340.2

Journal Article · Wed Feb 01 04:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/835/2/218· OSTI ID:22869457

Pan, Xiang; Zhou, Hongyan; Jiang, Peng; Lu, Honglin; Ji, Tuo ^[1]; Ge, Jian ^[2]; Yang, Bin ^[3]; Zhang, Shaohua; Shi, Xiheng ^[4]

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1. Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Sciences and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China)
2. Astronomy Department, University of Florida, 211 Bryant Space Science Center, P.O. Box 112055, Gainesville, FL 32611 (United States)
3. National Astronomical Observatories, Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)
4. Polar Research Institute of China, 451 Jinqiao Road, Shanghai 200136 (China)

We present a detailed analysis of the unusual damped Lyα absorption line system (DLA) toward the quasar SDSS J170542.91+354340.2 at a redshift of 2, previously reported by Noterdaeme et al. as one of the very few CO absorbers known to date at high z. This DLA is exceptional in that: (1) its extinction curve is similar to peculiar Milky Way sightlines penetrating star formation regions; (2) its absorption components are redshifted at a speed of several hundred km s{sup −1} compared to broad Balmer emission lines; (3) its gas-phase metallicity is super-solar as evaluated from more than 30 absorption lines; (4) detection of residual flux in the DLA trough and variability of C IV absorption is possible. Based on these facts, we argue that this dusty DLA is a good candidate for an intrinsic quasar 2175 Å absorber, and can originate from star formation regions of the quasar’s host galaxy. We discuss in detail the gas and dust properties, and the dust depletion. Follow-up observations, such as spectropolarimetry and optical/infrared spectroscopy, will help to confirm the system’s intrinsic nature and to explore how dust grains behave in the extreme environments proximate to quasars.

• OSTI ID: 22869457
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 835; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ABSORPTION SPECTROSCOPY
CARBON MONOXIDE
COMPARATIVE EVALUATIONS
COSMIC DUST
DETECTION
EMISSION
INFRARED SPECTRA
LYMAN LINES
METALLICITY
MILKY WAY
QUASARS
RED SHIFT
STARS
VELOCITY