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Resource Record Summary

Catalog Service:
QPQ VI. HI absorption of z~2 quasars

Short name: J/ApJ/776/136
IVOA Identifier: ivo://CDS.VizieR/J/ApJ/776/136
DOI (Digital Object Identifier): 10.26093/cds/vizier.17760136
Publisher: CDSivo://CDS[Pub. ID]
More Info: https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/776/136
VO Compliance: Level 2: This is a VO-compliant resource.
Status: active
Registered: 2015 Apr 27 13:25:27Z
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Description


With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We use a sample of 650 projected quasar pairs to study the HI Ly{alpha} absorption transverse to luminous, z~2 quasars at proper separations of 30kpc<R_{perp}_<1Mpc. In contrast to measurements along the line-of-sight, regions transverse to quasars exhibit enhanced HI Ly{alpha} absorption and a larger variance than the ambient intergalactic medium, with increasing absorption and variance toward smaller scales. Analysis of composite spectra reveals excess absorption characterized by a Ly{alpha} equivalent width profile W=2.3{AA} (R_{perp}_/100kpc)^-0.46^. We also observe a high (=~60%) covering factor of strong, optically thick HI absorbers (HI column N_HI_>10^17.3^/cm2) at separations R_{perp}_<200kpc, which decreases to ~20% at R_{perp}_=~1Mpc, but still represents a significant excess over the cosmic average. This excess of optically thick absorption can be described by a quasar-absorber cross-correlation function {xi}_QA_(r)=(r/r_0_)^{gamma}^ with a large correlation length r_0_=12.5_-1.4_^+2.7^h^-1^Mpc (comoving) and {gamma}=1.68_-0.30_^+0.14^. The HI absorption measured around quasars exceeds that of any previously studied population, consistent with quasars being hosted by massive dark matter halos M_halo_{approx}10^12.5^M_{sun}_ at z~2.5. The environments of these massive halos are highly biased toward producing optically thick gas, and may even dominate the cosmic abundance of Lyman limit systems and hence the intergalactic opacity to ionizing photons at z~2.5. The anisotropic absorption around quasars implies the transverse direction is much less likely to be illuminated by ionizing radiation than the line-of-sight.

More About this Resource

About the Resource Providers

This section describes who is responsible for this resource

Publisher: CDSivo://CDS[Pub. ID]

Creators:
Prochaska J.X.Hennawi J.F.Lee K.-G.Cantalupo S.Bovy J.Djorgovski S.G.Ellison S.L.Lau M.W.Martin C.L.Myers A.Rubin K.H.R.Simcoe R.A.

Contact Information:
X CDS support team
Email: cds-question at unistra.fr
Address: CDS
Observatoire de Strasbourg
11 rue de l'Universite
F-67000 Strasbourg
France

Status of This Resource

This section provides some status information: the resource version, availability, and relevant dates.

Version: n/a
Availability: This is an active resource.
  • This service provides only public data.
Relevant dates for this Resource:
  • Updated: 2017 Jun 27 06:37:56Z
  • Created: 2015 Apr 27 13:25:27Z

This resource was registered on: 2015 Apr 27 13:25:27Z
This resource description was last updated on: 2021 Oct 21 00:00:00Z

What This Resource is About

This section describes what the resource is, what it contains, and how it might be relevant.

Resource Class: CatalogService
This resource is a service that provides access to catalog data. You can extract data from the catalog by issuing a query, and the matching data is returned as a table.
Resource type keywords:
  • Catalog
Subject keywords:
  • Line intensities
  • Quasars
  • Redshifted
  • Spectroscopy
Intended audience or use:
  • Research: This resource provides information appropriate for supporting scientific research.
More Info: https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/776/136 Literature Reference: 2013ApJ...776..136P

Related Resources:

Other Related Resources
TAP VizieR generic service(IsServedBy) ivo://CDS.VizieR/TAP [Res. ID]
Conesearch service(IsServedBy)
VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012) ivo://CDS.VizieR/VII/269 [Res. ID]

Data Coverage Information

This section describes the data's coverage over the sky, frequency, and time.

Wavebands covered:

  • Optical

Rights and Usage Information

This section describes the rights and usage information for this data.

Rights:

Available Service Interfaces

Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:
Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:
  • URL-based interface: http://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/776/136
Table Access Protocol - Auxiliary ServiceXX

This is a standard IVOA service that takes as input an ADQL or PQL query and returns tabular data.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for the standard interface:
  • http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Simple Cone SearchXXSearch Me

This is a standard IVOA service that takes as input a position in the sky and a radius and returns catalog records with positions within that radius.

VO Compliance: Level 2: This is a VO-compliant resource.
Description:
Cone search capability for table J/ApJ/776/136/qpq6 (Quasars Probing Quasars VI (QPQ6) redshifts and HI measurements)
Available endpoints for the standard interface:
  • http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/776/136/qpq6?
Maximum search radius accepted: 180.0 degrees
Maximum number of matching records returned: 50000
This service supports the VERB input parameter:
Use VERB=1 to minimize the returned columns or VERB=3 to maximize.
Simple Cone SearchXXSearch Me

This is a standard IVOA service that takes as input a position in the sky and a radius and returns catalog records with positions within that radius.

VO Compliance: Level 2: This is a VO-compliant resource.
Description:
Cone search capability for table J/ApJ/776/136/table2 (Journal of observations)
Available endpoints for the standard interface:
  • http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/776/136/table2?
Maximum search radius accepted: 180.0 degrees
Maximum number of matching records returned: 50000
This service supports the VERB input parameter:
Use VERB=1 to minimize the returned columns or VERB=3 to maximize.


Developed with the support of the National Science Foundation
under Cooperative Agreement AST0122449 with the Johns Hopkins University
The NAVO project is a member of the International Virtual Observatory Alliance

This NAVO Application is hosted by the Space Telescope Science Institute

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