Mid-infrared evidence for accelerated evolution in compact group galaxies

Lisa May Walker, Kelsey E. Johnson, Sarah C. Gallagher, John E. Hibbard, Ann E. Hornschemeier, Panayiotis Tzanavaris, Jane Camilla Charlton, Thomas H. Jarrett

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Compact galaxy groups are at the extremes of the group environment, with high number densities and low velocity dispersions that likely affect member galaxy evolution. To explore the impact of this environment in detail, we examine the distribution in the mid-infrared (MIR) 3.6-8.0 μm color space of 42 galaxies from 12 Hickson compact groups (HCGs) in comparison with several control samples, including the LVL+SINGS galaxies, interacting galaxies, and galaxies from the Coma Cluster. We find that the HCG galaxies are strongly bimodal, with statistically significant evidence for a gap in their distribution. In contrast, none of the other samples show such a marked gap, and only galaxies in the Coma infall region have a distribution that is statistically consistent with the HCGs in this parameter space. To further investigate the cause of the HCG gap, we compare the galaxy morphologies of the HCG and LVL+SINGS galaxies, and also probe the specific star formation rate (SSFR) of the HCG galaxies. While galaxy morphology in HCG galaxies is strongly linked to position with MIR color space, the more fundamental property appears to be the SSFR, or star formation rate normalized by stellar mass. We conclude that the unusual MIR color distribution of HCG galaxies is a direct product of their environment, which is most similar to that of the Coma infall region. In both cases, galaxy densities are high, but gas has not been fully processed or stripped. We speculate that the compact group environment fosters accelerated evolution of galaxies from starforming and neutral gas-rich to quiescent and neutral gas-poor, leaving few members in the MIR gap at any time.

Original languageEnglish (US)
Pages (from-to)1254-1267
Number of pages14
JournalAstronomical Journal
Volume140
Issue number5
DOIs
StatePublished - Nov 1 2010

Fingerprint

galactic clusters
galaxies
gas
coma
star formation rate
neutral gases
color
probe
gases
distribution
compact galaxies
interacting galaxies
rate
stellar mass
low speed

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Walker, L. M., Johnson, K. E., Gallagher, S. C., Hibbard, J. E., Hornschemeier, A. E., Tzanavaris, P., ... Jarrett, T. H. (2010). Mid-infrared evidence for accelerated evolution in compact group galaxies. Astronomical Journal, 140(5), 1254-1267. https://doi.org/10.1088/0004-6256/140/5/1254
Walker, Lisa May ; Johnson, Kelsey E. ; Gallagher, Sarah C. ; Hibbard, John E. ; Hornschemeier, Ann E. ; Tzanavaris, Panayiotis ; Charlton, Jane Camilla ; Jarrett, Thomas H. / Mid-infrared evidence for accelerated evolution in compact group galaxies. In: Astronomical Journal. 2010 ; Vol. 140, No. 5. pp. 1254-1267.
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Walker, LM, Johnson, KE, Gallagher, SC, Hibbard, JE, Hornschemeier, AE, Tzanavaris, P, Charlton, JC & Jarrett, TH 2010, 'Mid-infrared evidence for accelerated evolution in compact group galaxies', Astronomical Journal, vol. 140, no. 5, pp. 1254-1267. https://doi.org/10.1088/0004-6256/140/5/1254

Mid-infrared evidence for accelerated evolution in compact group galaxies. / Walker, Lisa May; Johnson, Kelsey E.; Gallagher, Sarah C.; Hibbard, John E.; Hornschemeier, Ann E.; Tzanavaris, Panayiotis; Charlton, Jane Camilla; Jarrett, Thomas H.

In: Astronomical Journal, Vol. 140, No. 5, 01.11.2010, p. 1254-1267.

Research output: Contribution to journalArticle

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Walker LM, Johnson KE, Gallagher SC, Hibbard JE, Hornschemeier AE, Tzanavaris P et al. Mid-infrared evidence for accelerated evolution in compact group galaxies. Astronomical Journal. 2010 Nov 1;140(5):1254-1267. https://doi.org/10.1088/0004-6256/140/5/1254