Global properties of neutral hydrogen in compact groups

Lisa May Walker, Kelsey E. Johnson, Sarah C. Gallagher, George C. Privon, Amanda A. Kepley, David G. Whelan, Tyler D. Desjardins, Ann I Zabludoff

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Compact groups of galaxies provide a unique environment to study the evolution of galaxies amid frequent gravitational encounters. These nearby groups have conditions similar to those in the earlier universe when galaxies were assembled and give us the opportunity to witness hierarchical formation in progress. To understand how the compact group environment affects galaxy evolution, we examine the gas and dust in these groups. We present new single-dish GBT neutral hydrogen (H i) observations of 30 compact groups and define a new way to quantify the group H i content as the H i-to-stellar mass ratio of the group as a whole. We compare the H i content with mid-IR indicators of star formation and optical [g - r] color to search for correlations between group gas content and star formation activity of individual group members. Quiescent galaxies tend to live in H i-poor groups, and galaxies with active star formation are more commonly found in H i-rich groups. Intriguingly, we also find "rogue" galaxies whose star formation does not correlate with group H i content. In particular, we identify three galaxies (NGC 2968 in RSCG 34, KUG 1131+202A in RSCG 42, and NGC 4613 in RSCG 64) whose mid-IR activity is discrepant with the H i. We speculate that this mismatch between mid-IR activity and H i content is a consequence of strong interactions in this environment that can strip H i from galaxies and abruptly affect star formation. Ultimately, characterizing how and on what timescales the gas is processed in compact groups will help us understand the interstellar medium in complex, dense environments similar to the earlier universe.

Original languageEnglish (US)
Article number30
JournalAstronomical Journal
Volume151
Issue number2
DOIs
StatePublished - Feb 1 2016

Fingerprint

hydrogen
galaxies
gas
star formation
dust
timescale
universe
gases
parabolic reflectors
stellar mass
encounters
mass ratios
strip
color
indicator

Keywords

  • galaxies: evolution
  • galaxies: groups: general
  • galaxies: interactions
  • galaxies: ISM
  • intergalactic medium
  • ISM: general

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Walker, L. M., Johnson, K. E., Gallagher, S. C., Privon, G. C., Kepley, A. A., Whelan, D. G., ... Zabludoff, A. I. (2016). Global properties of neutral hydrogen in compact groups. Astronomical Journal, 151(2), [30]. https://doi.org/10.3847/0004-6256/151/2/30

Global properties of neutral hydrogen in compact groups. / Walker, Lisa May; Johnson, Kelsey E.; Gallagher, Sarah C.; Privon, George C.; Kepley, Amanda A.; Whelan, David G.; Desjardins, Tyler D.; Zabludoff, Ann I.

In: Astronomical Journal, Vol. 151, No. 2, 30, 01.02.2016.

Research output: Contribution to journalArticle

Walker, LM, Johnson, KE, Gallagher, SC, Privon, GC, Kepley, AA, Whelan, DG, Desjardins, TD & Zabludoff, AI 2016, 'Global properties of neutral hydrogen in compact groups', Astronomical Journal, vol. 151, no. 2, 30. https://doi.org/10.3847/0004-6256/151/2/30
Walker LM, Johnson KE, Gallagher SC, Privon GC, Kepley AA, Whelan DG et al. Global properties of neutral hydrogen in compact groups. Astronomical Journal. 2016 Feb 1;151(2). 30. https://doi.org/10.3847/0004-6256/151/2/30
Walker, Lisa May ; Johnson, Kelsey E. ; Gallagher, Sarah C. ; Privon, George C. ; Kepley, Amanda A. ; Whelan, David G. ; Desjardins, Tyler D. ; Zabludoff, Ann I. / Global properties of neutral hydrogen in compact groups. In: Astronomical Journal. 2016 ; Vol. 151, No. 2.
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