English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  The evolution of O i over 3.2 < z < 6.5: reionization of the circumgalactic medium

Becker, G. D., Pettini, M., Rafelski, M., D’Odorico, V., Boera, E., Christensen, L., et al. (2019). The evolution of O i over 3.2 < z < 6.5: reionization of the circumgalactic medium. The Astrophysical Journal, 883(2): 163. doi:10.3847/1538-4357/ab3eb5.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0005-59D2-A Version Permalink: http://hdl.handle.net/21.11116/0000-0005-59D3-9
Genre: Journal Article

Files

show Files
hide Files
:
The Evolution of O i over 3.2 z 6.5 Reionization of the Circumgalactic Medium.pdf (Any fulltext), 13MB
 
File Permalink:
-
Name:
The Evolution of O i over 3.2 z 6.5 Reionization of the Circumgalactic Medium.pdf
Description:
-
Visibility:
Private
MIME-Type / Checksum:
application/pdf
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Becker, George D., Author
Pettini, Max, Author
Rafelski, Marc, Author
D’Odorico, Valentina, Author
Boera, Elisa, Author
Christensen, Lise, Author
Cupani, Guido, Author
Ellison, Sara L., Author
Farina, Emanuele Paolo1, Author              
Fumagalli, Michele, Author
López, Sebastian, Author
Neeleman, Marcel, Author
Ryan-Weber, Emma V., Author
Worseck, Gábor, Author
Affiliations:
1Cosmology, MPI for Astrophysics, Max Planck Society, ou_159876              

Content

show
hide
Free keywords: -
 Abstract: We present a survey for metal absorption systems traced by neutral oxygen over 3.2 < z < 6.5. Our survey uses Keck/ESI and VLT/X-Shooter spectra of 199 QSOs with redshifts up to 6.6. In total, we detect 74 O i absorbers, of which 57 are separated from the background QSO by more than 5000 km s−1. We use a maximum likelihood approach to fit the distribution of O i λ1302 equivalent widths in bins of redshift and from this determine the evolution in number density of absorbers with W 1302 > 0.05 Å, of which there are 49 nonproximate systems in our sample. We find that the number density does not monotonically increase with decreasing redshift, as would naively be expected from the buildup of metal-enriched circumgalactic gas with time. The number density over 4.9 < z < 5.7 is a factor of 1.7–4.1 lower (68% confidence) than that over 5.7 < z < 6.5, with a lower value at z < 5.7 favored with 99% confidence. This decrease suggests that the fraction of metals in a low-ionization phase is larger at z ~ 6 than at lower redshifts. Absorption from highly ionized metals traced by C iv is also weaker in higher-redshift O i systems, supporting this picture. The evolution of O i absorbers implies that metal-enriched circumgalactic gas at z ~ 6 is undergoing an ionization transition driven by a strengthening ultraviolet background. This in turn suggests that the reionization of the diffuse intergalactic medium may still be ongoing at or only recently ended by this epoch.

Details

show
hide
Language(s):
 Dates: 2019-10-01
 Publication Status: Published online
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: DOI: 10.3847/1538-4357/ab3eb5
Other: LOCALID: 3181930
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: The Astrophysical Journal
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Bristol; Vienna : IOP Publishing; IAEA
Pages: - Volume / Issue: 883 (2) Sequence Number: 163 Start / End Page: - Identifier: ISSN: 0004-637X
CoNE: https://pure.mpg.de/cone/journals/resource/954922828215_3