The Multi-phase Absorption Systems Toward PG 1206+459

Abstract

A high-resolution HST/STIS spectrum (R=30,000) is presented of the three MgII-selected absorption systems (A, B, and C, clustered within 1500km/s) at z~0.93 toward the quasar PG 1206+459. A WIYN Gunn i-band image of the quasar field and spectroscopy of two galaxy candidates are also presented. A multi-phase medium is seen in all three systems, consistent with smaller, denser clouds producing low-ionization transitions (MgII, FeII, and SiII) and larger, diffuse clouds giving rise to high-ionization transitions (CIV, NV, and/or OVI). (1) System A, a multi-cloud, weak MgII absorber at z=0.9254, requires a super-solar metallicity in both low- and high-ionization phases, unless an alpha-group enhancement is included. With the unusually complex velocity structure resolved in the NV profiles, this system is unlikely to represent a traditional galaxy disk/corona. The most likely candidate host galaxy is a ~2L^*, apparently warped, spiral at an impact parameter of 43h^-1 kpc. (2) System B, at z=0.9276, has the strongest MgII absorption and has an approximately solar metallicity in the low-ionization phase. The smooth, broad high-ionization profiles may indicate a coronal structure similar to that of the Milky Way. The redshift of an L^* galaxy (z=0.9289), at an impact parameter of 38h^-1 kpc is consistent with the redshift of this system. (3) System C, at z=0.9342, has a single component in MgII, separated from the other two systems by ~1000km/s. It lacks the small, low-ionization cloud characteristic of an isolated single-cloud, weak MgII absorber. Its absorption properties are similar to the ``satellite clouds'' of classic strong MgII absorbers, so this could be a high-velocity cloud in the galaxy group responsible for the systems, possibly related to a 0.2L^* galaxy at an impact parameter of 43h^-1 kpc.

52 pages, 9 figures; to appear in ApJ, June 20, 2003

References in corpus (8)

• The Kinematic Connection Between QSO-Absorbing Gas and Galaxies at Intermediate Redshift
• HIPASS High-Velocity Clouds: Properties of the Compact and Extended Populations
• The Origin of C IV Absorption Systems at Redshifts z<1---Discovery of Extended C IV Envelopes Around Galaxies
• The Population of Weak MgII Absorbers. II The Properties of Single-Cloud Systems
• The Ionization and Metallicity of the Intervening O VI Absorber at z = 0.1212 in the Spectrum of H1821+643
• The Kinematics of Intermediate Redshift Mg II Absorbers
• High Resolution STIS/HST and HIRES/Keck Spectra of Three Weak MgII Absorbers Toward PG 1634+706
• A Quadruple-Phase Strong Mg II Absorber at z~0.9902 Toward PG 1634+706

Cited by in corpus (36)

• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release
• The Hidden Mass and Large Spatial Extent of a Poststarburst Galaxy Outflow
• Halo Gas and Galaxy Disk Kinematics Derived from Observations and LCDM Simulations of MgII Absorption Selected Galaxies at Intermediate Redshift
• An Extreme Metallicity, Large-Scale Outflow from a Star-Forming Galaxy at z ~ 0.4
• AGN proximity zone fossils and the delayed recombination of metal lines
• The Most Metal-Rich Intervening Quasar Absorber Known
• A MIKE + UVES survey of Sub-Damped Lyman-Alpha Systems at z<1.5
• Direct Insights into Observational Absorption Line Analysis Methods of the Circumgalactic Medium Using Cosmological Simulations
• CaII and NaI absorption signatures from extraplanar gas in the halo of the Milky Way
• The nature of damped Lyman alpha and sub-damped Lyman alpha absorbers
• Do Damped and Sub-damped Lyman-alpha Absorbers Arise in Galaxies of Different Masses?
• The COS Absorption Survey of Baryon Harbors: Unveiling the Physical Conditions of Circumgalactic Gas through Multiphase Bayesian Ionization Modeling
• The Absorption Signatures of Dwarf Galaxies: The z=1.04 Multicloud Weak MgII Absorber toward PG 1634+706
• The High-Ion Content and Kinematics of Low-Redshift Lyman Limit Systems
• An absorption-selected survey of neutral gas in the Milky Way halo
• The chemical compositions of 10 new sub-DLAs and strong Lyman-limit systems at z < 1.5
• The Absorption Signature of Six MgII-Selected Systems Over 0.5<z<0.9
• Models of Five Absorption Line Systems Along the Line of Sight Toward PG0117+213
• Cosmic Origins Spectrograph Observations of Warm Intervening Gas Towards 3C263
• A Survey of Analogs to Weak MgII Absorbers in the Present
• Cloud-by-cloud, multiphase, Bayesian modeling: Application to four weak, low ionization absorbers
• On the Connection Between Metal Absorbers and Quasar Nebulae
• Understanding the strong intervening OVI absorber at z${}_{abs}$ ~0.93 towards PG1206+459
• A Census of Quasar-Intrinsic Absorption in the Hubble Space Telescope Archive: Systems from High Resolution Echelle Spectra
• Testing the Possible Intrinsic Origin of the Excess of Very Strong MgII Absorbers Along GRB Lines-of-Sight
• The Nature of Weak MgII Absorbing Structures
• Super-Solar Metallicity in Weak Mg II Absorption Systems at z ~ 1.7
• Abundances and kinematics of a candidate sub-damped Lyman-alpha galaxy toward PHL 1226
• Using cosmological simulations and synthetic absorption spectra to assess the accuracy of observationally derived CGM metallicities
• The COS-legacy survey of C IV absorbers: properties and origins of the intervening systems
• On the Covering Fraction Variability in an EUV Mini-BAL Outflow from PG 1206+459
• The UV spectrum of HS1700+6416 I. Predicting the metal line content of the far UV spectrum
• Detection of Low Metallicity Warm Plasma in a Galaxy Overdensity Environment at z ~ 0.2
• A Catalog of Absorption Lines in Eight HST/STIS E230M 1.0 < z < 1.7 Quasar Spectra
• Galactic Winds across the Gas-Rich Merger Sequence II. Lyman Alpha Emission and Highly Ionized O VI and N V Outflows in Ultraluminous Infrared Galaxies
• The Halo21 Absorption Modeling Challenge: Lessons From "Observing" Synthetic Circumgalactic Absorption Spectra