The Ultraviolet Detection of Diffuse Gas in Galaxy Groups

John T. Stocke, Brian A. Keeney, Charles W. Danforth, Benjamin D. Oppenheimer, Cameron T. Pratt, Andreas A. Berlind, Christopher D Impey, Buell Tomasson Jannuzi

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 virial radii) to a group galaxy, to ensure absorber association with the group as a whole. Deeper galaxy redshift observations are used both to search for closer galaxies and also to characterize these 10 13.5 -10 14.5 M o groups, the most massive of which are highly virialized with numerous early-type galaxies (ETGs). This sample also includes two spiral-rich groups, not yet fully virialized. At group-centric impact parameters of 0.3-2 Mpc, these signal-to-noise ratios = 15-30 spectra detected H i absorption in 7 of 12 groups; high (O vi) and low (Si iii) ion metal lines are present in two-thirds of the absorption components. None of the three most highly virialized, ETG-dominated groups are detected in absorption. Covering fractions 50% are seen at all impact parameters probed, but do not require large filling factors despite an enormous extent. Unlike halo clouds in individual galaxies, group absorbers have radial velocities that are too low to escape the group potential well without doubt. This suggests that these groups are "closed boxes" for galactic evolution in the current epoch. Evidence is presented that the cool and warm group absorbers are not a pervasive intra-group medium (IGrM), requiring a hotter (T ∼ 10 6 -10 7 K) IGrM to be present to close the baryon accounting.

Original languageEnglish (US)
Article number15
JournalAstrophysical Journal, Supplement Series
Volume240
Issue number1
DOIs
StatePublished - Jan 1 2019

Fingerprint

galactic clusters
gases
gas
signal-to-noise ratio
absorbers
ion
metal
galaxies
detection
visual perception
galactic evolution
parameter
Hubble Space Telescope
radial velocity
escape
spectrographs
boxes
baryons
halos
metal ions

Keywords

  • galaxies: evolution
  • galaxies: groups: general
  • galaxies: halos
  • intergalactic medium
  • quasars: absorption lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Stocke, J. T., Keeney, B. A., Danforth, C. W., Oppenheimer, B. D., Pratt, C. T., Berlind, A. A., ... Jannuzi, B. T. (2019). The Ultraviolet Detection of Diffuse Gas in Galaxy Groups. Astrophysical Journal, Supplement Series, 240(1), [15]. https://doi.org/10.3847/1538-4365/aaf73d

The Ultraviolet Detection of Diffuse Gas in Galaxy Groups. / Stocke, John T.; Keeney, Brian A.; Danforth, Charles W.; Oppenheimer, Benjamin D.; Pratt, Cameron T.; Berlind, Andreas A.; Impey, Christopher D; Jannuzi, Buell Tomasson.

In: Astrophysical Journal, Supplement Series, Vol. 240, No. 1, 15, 01.01.2019.

Research output: Contribution to journalArticle

Stocke, JT, Keeney, BA, Danforth, CW, Oppenheimer, BD, Pratt, CT, Berlind, AA, Impey, CD & Jannuzi, BT 2019, 'The Ultraviolet Detection of Diffuse Gas in Galaxy Groups', Astrophysical Journal, Supplement Series, vol. 240, no. 1, 15. https://doi.org/10.3847/1538-4365/aaf73d
Stocke JT, Keeney BA, Danforth CW, Oppenheimer BD, Pratt CT, Berlind AA et al. The Ultraviolet Detection of Diffuse Gas in Galaxy Groups. Astrophysical Journal, Supplement Series. 2019 Jan 1;240(1). 15. https://doi.org/10.3847/1538-4365/aaf73d
Stocke, John T. ; Keeney, Brian A. ; Danforth, Charles W. ; Oppenheimer, Benjamin D. ; Pratt, Cameron T. ; Berlind, Andreas A. ; Impey, Christopher D ; Jannuzi, Buell Tomasson. / The Ultraviolet Detection of Diffuse Gas in Galaxy Groups. In: Astrophysical Journal, Supplement Series. 2019 ; Vol. 240, No. 1.
@article{39e627221e9e48f9b1909684dc212558,
title = "The Ultraviolet Detection of Diffuse Gas in Galaxy Groups",
abstract = "A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 virial radii) to a group galaxy, to ensure absorber association with the group as a whole. Deeper galaxy redshift observations are used both to search for closer galaxies and also to characterize these 10 13.5 -10 14.5 M o groups, the most massive of which are highly virialized with numerous early-type galaxies (ETGs). This sample also includes two spiral-rich groups, not yet fully virialized. At group-centric impact parameters of 0.3-2 Mpc, these signal-to-noise ratios = 15-30 spectra detected H i absorption in 7 of 12 groups; high (O vi) and low (Si iii) ion metal lines are present in two-thirds of the absorption components. None of the three most highly virialized, ETG-dominated groups are detected in absorption. Covering fractions 50{\%} are seen at all impact parameters probed, but do not require large filling factors despite an enormous extent. Unlike halo clouds in individual galaxies, group absorbers have radial velocities that are too low to escape the group potential well without doubt. This suggests that these groups are {"}closed boxes{"} for galactic evolution in the current epoch. Evidence is presented that the cool and warm group absorbers are not a pervasive intra-group medium (IGrM), requiring a hotter (T ∼ 10 6 -10 7 K) IGrM to be present to close the baryon accounting.",
keywords = "galaxies: evolution, galaxies: groups: general, galaxies: halos, intergalactic medium, quasars: absorption lines",
author = "Stocke, {John T.} and Keeney, {Brian A.} and Danforth, {Charles W.} and Oppenheimer, {Benjamin D.} and Pratt, {Cameron T.} and Berlind, {Andreas A.} and Impey, {Christopher D} and Jannuzi, {Buell Tomasson}",
year = "2019",
month = "1",
day = "1",
doi = "10.3847/1538-4365/aaf73d",
language = "English (US)",
volume = "240",
journal = "Astrophysical Journal, Supplement Series",
issn = "0067-0049",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - The Ultraviolet Detection of Diffuse Gas in Galaxy Groups

AU - Stocke, John T.

AU - Keeney, Brian A.

AU - Danforth, Charles W.

AU - Oppenheimer, Benjamin D.

AU - Pratt, Cameron T.

AU - Berlind, Andreas A.

AU - Impey, Christopher D

AU - Jannuzi, Buell Tomasson

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 virial radii) to a group galaxy, to ensure absorber association with the group as a whole. Deeper galaxy redshift observations are used both to search for closer galaxies and also to characterize these 10 13.5 -10 14.5 M o groups, the most massive of which are highly virialized with numerous early-type galaxies (ETGs). This sample also includes two spiral-rich groups, not yet fully virialized. At group-centric impact parameters of 0.3-2 Mpc, these signal-to-noise ratios = 15-30 spectra detected H i absorption in 7 of 12 groups; high (O vi) and low (Si iii) ion metal lines are present in two-thirds of the absorption components. None of the three most highly virialized, ETG-dominated groups are detected in absorption. Covering fractions 50% are seen at all impact parameters probed, but do not require large filling factors despite an enormous extent. Unlike halo clouds in individual galaxies, group absorbers have radial velocities that are too low to escape the group potential well without doubt. This suggests that these groups are "closed boxes" for galactic evolution in the current epoch. Evidence is presented that the cool and warm group absorbers are not a pervasive intra-group medium (IGrM), requiring a hotter (T ∼ 10 6 -10 7 K) IGrM to be present to close the baryon accounting.

AB - A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 virial radii) to a group galaxy, to ensure absorber association with the group as a whole. Deeper galaxy redshift observations are used both to search for closer galaxies and also to characterize these 10 13.5 -10 14.5 M o groups, the most massive of which are highly virialized with numerous early-type galaxies (ETGs). This sample also includes two spiral-rich groups, not yet fully virialized. At group-centric impact parameters of 0.3-2 Mpc, these signal-to-noise ratios = 15-30 spectra detected H i absorption in 7 of 12 groups; high (O vi) and low (Si iii) ion metal lines are present in two-thirds of the absorption components. None of the three most highly virialized, ETG-dominated groups are detected in absorption. Covering fractions 50% are seen at all impact parameters probed, but do not require large filling factors despite an enormous extent. Unlike halo clouds in individual galaxies, group absorbers have radial velocities that are too low to escape the group potential well without doubt. This suggests that these groups are "closed boxes" for galactic evolution in the current epoch. Evidence is presented that the cool and warm group absorbers are not a pervasive intra-group medium (IGrM), requiring a hotter (T ∼ 10 6 -10 7 K) IGrM to be present to close the baryon accounting.

KW - galaxies: evolution

KW - galaxies: groups: general

KW - galaxies: halos

KW - intergalactic medium

KW - quasars: absorption lines

UR - http://www.scopus.com/inward/record.url?scp=85062622037&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062622037&partnerID=8YFLogxK

U2 - 10.3847/1538-4365/aaf73d

DO - 10.3847/1538-4365/aaf73d

M3 - Article

AN - SCOPUS:85062622037

VL - 240

JO - Astrophysical Journal, Supplement Series

JF - Astrophysical Journal, Supplement Series

SN - 0067-0049

IS - 1

M1 - 15

ER -