Eclipsing damped Ly$\alpha$ systems in the Sloan Digital Sky Survey Data Release 12

Abstract

We present the results of our automatic search for proximate damped Ly$\alpha$ absorption (PDLA) systems in the quasar spectra from the Sloan Digital Sky Survey Data Release 12. We constrain our search to those PDLAs lying within 1500 km s${}^{-1}$ from the quasar to make sure that the broad DLA absorption trough masks most of the strong Ly$\alpha$ emission from the broad line region (BLR) of the quasar. When the Ly$\alpha$ emission from the BLR is blocked by these so-called eclipsing DLAs, narrow Ly$\alpha$ emission from the host galaxy could be revealed as a narrow emission line (NEL) in the DLA trough. We define a statistical sample of 399 eclipsing DLAs with log$N$(HI)$\ge$21.10. We divide our statistical sample into three subsamples based on the strength of the NEL detected in the DLA trough. By studying the stacked spectra of these subsamples, we found that absorption from high ionization species are stronger in DLAs with stronger NEL in their absorption core. Moreover, absorption from the excited states of species like SiII are also stronger in DLAs with stronger NEL. We also found no correlation between the luminosity of the Ly$\alpha$ NEL and the quasar luminosity. These observations are consistent with a scenario in which the DLAs with stronger NEL are denser and physically closer to the quasar. We propose that these eclipsing DLAs could be the product of the interaction between infalling and outflowing gas. High resolution spectroscopic observation would be needed to shed some light on the nature of these eclipsing DLAs.

arXiv commentAccepted for publication in MNRAS, 16 pages, 20 figures, 3 tables. Full version of Tables 1 and 2 can be accessed via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/MNRAS

References in corpus (62)

• How Do Galaxies Get Their Gas?
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• Virial shocks in galactic haloes?
• The Structure and Kinematics of the Circum-Galactic Medium from Far-UV Spectra of z~2-3 Galaxies
• The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• Column density distribution and cosmological mass density of neutral gas: Sloan Digital Sky Survey-III Data Release 9
• Absorption line systems in simulated galaxies fed by cold streams
• Evolution of the cosmological mass density of neutral gas from Sloan Digital Sky Survey II - Data Release 7
• Gas accretion as the origin of chemical abundance gradients in distant galaxies
• A Population of Faint Extended Line Emitters and the Host Galaxies of Optically Thick QSO Absorption Systems
• The Bimodal Metallicity Distribution of the Cool Circumgalactic Medium at z<1
• The circumgalactic medium of massive galaxies at z~3: a test for stellar feedback, galactic outflows, and cold streams
• Size and Structure of the Narrow-Line Region of Quasars
• The Small Covering Factor of Cold Accretion Streams
• The VLT-UVES survey for molecular hydrogen in high-redshift damped Lyman-alpha systems: Physical conditions in the neutral gas
• Properties of gas in and around galaxy haloes
• The Direct Detection of Cool, Metal-Enriched Gas Accretion onto Galaxies at z ~ 0.5
• Scaling Relations Between Warm Galactic Outflows and Their Host Galaxies
• Cold accretion flows and the nature of high column density HI absorption at redshift 3
• A Principal Component Analysis of quasar UV spectra at z~3
• Quasars Probing Quasars III: New Clues to Feedback, Quenching, and the Physics of Massive Galaxy Formation
• The Ucsd/Keck Damped Lya Abundance Database: A Decade of High Resolution Spectroscopy
• The large-scale Quasar-Lyman α Forest Cross-Correlation from BOSS
• MusE GAs FLOw and Wind (MEGAFLOW) I: First MUSE results on background quasars
• A Survey for NV Absorption at z~z_GRB in GRB Afterglow Spectra: Clues to Gas Near the Progenitor Star
• A connection between extremely strong Damped Lyman-alpha Systems and Lyman-alpha Emitting Galaxies at small impact parameters
• Physical conditions in QSO absorbers from fine-structure absorption lines
• EVLA Observations of Galactic Supernova Remnants: Wide-field Continuum and Spectral-index Imaging
• Observing the End of Cold Flow Accretion using Halo Absorption Systems
• The Cosmic Evolution of the Metallicity Distribution of Ionized Gas Traced by Lyman Limit Systems
• The SDSS Damped Lya Survey: Data Release 1
• Quasars probing intermediate redshift star-forming galaxies
• The nature of proximate damped Lyman alpha systems
• Low-metallicity Absorbers Account for Half of the Dense Circumgalactic Gas at z < 1
• Are cold flows detectable with metal absorption lines?
• Bimodality in Damped Lyman alpha Systems
• Discovery Of Cold, Pristine Gas Possibly Accreting Onto An Overdensity Of Star-Forming Galaxies At Redshift z ~ 1.6
• Resolving the optical emission lines of Lya blob 'B1' at z=2.38: another hidden quasar
• Observational signatures of a warped disk associated with cold-flow accretion
• A z = 3 Lyman Alpha Blob Associated with a Damped Lyman Alpha System Proximate to its Background Quasar
• The Keck+Magellan Survey for Lyman Limit Absorption III: Sample Definition and Column Density Measurements
• Galactic Winds with MUSE: A Direct Detection of FeII* Emission from a z = 1.29 Galaxy
• A near-solar metallicity damped Lyman-alpha system toward the BAL quasar Tol 1037-2703
• A glance at the host galaxy of high-redshift quasars using strong damped Lyman-alpha systems as coronagraphs
• A collimated flow driven by radiative pressure from the nucleus of quasar Q~1511+091
• Metal-Enriched Plasma in Protogalactic Halos: A Survey of N V Absorption in High-z Damped & Sub-Damped Lyman-alpha Systems
• The Incidence of Low-Metallicity Lyman-Limit Systems at z~3.5: Implications for the Cold-Flow Hypothesis of Baryonic Accretion
• Supernova-Driven Outflows in NGC 7552: A Comparison of H-alpha and UV Tracers
• On the evolution of gas clouds exposed to AGN radiation. I. Three-dimensional radiation hydrodynamic simulations
• Galaxy Outflows Without Supernovae
• A ghostly damped Ly$\alpha$ system revealed by metal absorption lines
• A New Constraint on the Physical Nature of Damped Lyman Alpha Systems
• Extended Ly$\alpha$ emission around quasars with eclipsing damped Ly$\alpha$ systems
• Predominantly Low Metallicities Measured in a Stratified Sample of Lyman Limit Systems at z=3.7
• Average [O II] nebular emission associated with Mg II absorbers: Dependence on Fe II absorption
• [O II] nebular emission from Mg II absorbers: Star formation associated with the absorbing gas
• A coronagraphic absorbing cloud reveals the narrow-line region and extended Lyman-$\alpha$ emission of QSO J0823+0529
• An investigation of the line of sight towards QSO PKS 0237-233
• Constraining the size of the narrow line region in distant quasars
• Spectral atlases of the Sun from 3980 to 7100 Å at the center and at the limb
• Understanding Lyman-alpha emitters

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• Proximate Molecular Quasar Absorbers: Excess of damped H2 systems at zabs~zQSO in SDSS DR14
• A giant Ly$\alpha$ nebula and a small-scale clumpy outflow in the system of the exotic quasar J0952+0114 unveiled by MUSE
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• Ghostly Damped Ly$\alpha$ Systems: Tracers of Gas Flows in the Close Vicinity of Quasars ?
• Deep Learning Prediction of Quasars Broad Ly$\alpha$ Emission Line
• Using Machine Learning to Find Ghostly Damped Ly$\alpha$ Systems in SDSS DR14
• HI gas playing hide-and-seek around a powerful FRI-type quasar at z$\sim$2.1
• Lyman-$\alpha$ emission from a WISE-selected optically faint powerful radio galaxy M151304.72-252439.7 at $z$ = 3.132
• Deep Hubble Space Telescope Imaging on the Extended Ly$\alpha$ Emission of a QSO at $z=2.19$ with Damped Lyman Alpha System as a Natural Coronagraph
• A Strange EUV Emission: Scattered Continuum in the Lymann Limit Absorption Edge toward the Quasar SDSS J125903.26+621211.5?
• Constraining the Metallicities of Damped Ly$\alpha$ Systems Using Extinction Curves