A Study of Lyman-Alpha Quasar Absorbers in the Nearby Universe

Abstract

Spectroscopy of ten quasars obtained with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) is presented. A clustering analysis reveals an excess of nearest neighbor line pairs on velocity scales of 250-750 km/s at a 95-98% confidence level. The hypothesis that the absorbers are randomly distributed in velocity space can be ruled out at the 99.8% confidence level. No two-point correlation power is detected (xi < 1 with 95% confidence). Lyman-alpha absorbers have correlation amplitudes on scales of 250-500 km/s at least 4-5 times smaller than the correlation amplitude of bright galaxies. A detailed comparison between absorbers in nearby galaxies is carried out on a limited subset of 11 Lyman- alpha absorbers where the galaxy sample in a large contiguous volume is complete to M_B = -16. Absorbers lie preferentially in regions of intermediate galaxy density but it is often not possible to uniquely assign a galaxy counterpart to an absorber. This sample provides no explicit support for the hypothesis that absorbers are preferentially associated with the halos of luminous galaxies. We have made a preliminary comparison of the absorption line properties and environments with the results of hydrodynamic simulations. The results suggest that the Lyman-alpha absorbers represent diffuse or shocked gas in the IGM that traces the cosmic web of large scale structure. (abridged)

36 pages of text, 15 figures, 4 tables, 36 files

Cited by in corpus (42)

• A high velocity ionised outflow and XUV photosphere in the narrow emission line quasar PG1211+143
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy
• The Local Ly-alpha Forest IV: STIS G140M Spectra and Results on the Distribution and Baryon Content of HI Absorbers
• The Gaseous Extent of Galaxies and the Origin of Lya Absorption Systems. V. Optical and Near-Infrared Photometry of Lya-absorbing Galaxies at z < 1
• Physical Properties, Baryon Content, and Evolution of the LyαForest: New Insights from High Resolution Observations at z < 0.4
• The physical properties of the Ly-Alpha forest at z > 1.5
• The Galaxy Environment of O VI Absorption Systems
• The Local Lya Forest. III. Relationship between Lya Absorbers and Galaxies, Voids and Superclusters
• The Relationship Between Intergalactic HI/OVI and Nearby (z<0.017) Galaxies
• The Lyman-Alpha Forest at 1.5 < z < 4
• The Local Lyman-alpha Forest. II: Distribution of HI Absorbers, Doppler Widths, and Baryon Content
• Discovery of a Primitive Damped Lyman alpha Absorber Near an X-ray Bright Galaxy Group in the Virgo Cluster
• The Heavy Element Enrichment of Lyman alpha Clouds in the Virgo Supercluster
• A Uniform Analysis of the Ly-alpha Forest at z=0 - 5: V. The extragalactic ionizing background at low redshift
• The Hot Intergalactic Medium - Galaxy Connection: Two Strong Absorbers in the Sightline Toward PG 1211+143
• The Local Lyman-alpha Forest. I: Observations with the GHRS/G160M on the Hubble Space Telescope
• The Evolution of Lyman alpha Absorbers in the Redshift Range 0.5<z<1.9
• On the connection between the intergalactic medium and galaxies: The HI-galaxy cross-correlation at z < 1
• Probing the IGM/Galaxy Connection Toward PKS0405-123 III: The Galaxy Survey and Correlations with OVI Absorbers
• The Connection between a Lyman Limit System, a very strong OVI Absorber, and Galaxies at z~0.203
• High Metallicity, Photoionised Gas in Intergalactic Large-Scale Filaments
• Warm Gas in the Virgo Cluster: I. Distribution of Lya Absorbers
• HST/COS Spectra of Three QSOs That Probe The Circumgalactic Medium of a Single Spiral Galaxy: Evidence for Gas Recycling and Outflow
• Discovery of a Dwarf Post-Starburst Galaxy Near a High Column Density Ly-alpha Absorber
• The Low Surface Brightness Extent of the Fornax Cluster
• Cross correlation of Lyman-alpha absorbers with gas-rich galaxies
• The Low-Redshift Lyman Alpha Forest toward PKS 0405-123
• The Local Lyman-Alpha Forest: Absorbers in Galaxy Voids
• An Intrinsic Absorption Complex Toward RXJ1230.8+0115: Geometry and Photoionization Conditions
• Intense look at Virgo Southern Extension
• Evidence for Large Scale Structure in the Lyman alpha Forest at z>2.6
• The association between gas and galaxies I: CFHT spectroscopy and pair analysis
• A uniform analysis of the Lyman alpha forest at z = 0-5: IV. The clustering and evolution of clouds at z < 1.7
• Discovery of a Metal-Line Absorber Associated with a Local Dwarf Starburst Galaxy
• The Low-Redshift Lyman Alpha Forest toward 3C 273
• Lyman-Alpha Absorption in the Quasar Triplet Q0107-025A, Q0107-025B, and Q0107-0232: Data Calibration and Line Selection
• QSOs and Absorption Line Systems Surrounding the Hubble Deep Field
• The Relationship Between Baryons and Dark Matter in Extended Galaxy Halos
• The strange case of a sub-DLA with very little HI
• Quasars as Absorption Probes of the J0053+1234 Region
• Low Redshift QSO Lyman alpha Absorption Line Systems Associated with Galaxies
• Line versus Flux Statistics -- Considerations for the Low Redshift Lyman-alpha Forest