Galaxy evolution in a complex environment

A multi-wavelength study of HCG 7

I. S. Konstantopoulos, S. C. Gallagher, K. Fedotov, P. R. Durrell, A. Heiderman, D. M. Elmegreen, Jane Camilla Charlton, J. E. Hibbard, P. Tzanavaris, R. Chandar, K. E. Johnson, A. Maybhate, A. E. Zabludoff, Caryl Ann Gronwall, D. Szathmary, A. E. Hornschemeier, J. English, B. Whitmore, C. Mendes De Oliveira, J. S. Mulchaey

Research output: Contribution to journalArticle

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Abstract

The environment where galaxies are found heavily influences their evolution. Close groupings, like the ones in the cores of galaxy clusters or compact groups, evolve in ways far more dramatic than their isolated counterparts. We have conducted a multi-wavelength study of Hickson Compact Group 7 (HCG 7), consisting of four giant galaxies: three spirals and one lenticular. We use Hubble Space Telescope (HST) imaging to identify and characterize the young and old star cluster populations. We find young massive clusters (YMCs) mostly in the three spirals, while the lenticular features a large, unimodal population of globular clusters (GCs) but no detectable clusters with ages less than a few Gyr. The spatial and approximate age distributions of the ∼300 YMCs and ∼150 GCs thus hint at a regular star formation history in the group over a Hubble time. While at first glance the HST data show the galaxies as undisturbed, our deep ground-based, wide-field imaging that extends the HST coverage reveals faint signatures of stellar material in the intragroup medium (IGM). We do not, however, detect the IGM in HI or Chandra X-ray observations, signatures that would be expected to arise from major mergers. Despite this fact, we find that the HI gas content of the individual galaxies and the group as a whole are a third of the expected abundance. The appearance of quiescence is challenged by spectroscopy that reveals an intense ionization continuum in one galaxy nucleus, and post-burst characteristics in another. Our spectroscopic survey of dwarf galaxy members yields a single dwarf elliptical galaxy in an apparent stellar tidal feature. Based on all this information, we suggest an evolutionary scenario for HCG 7, whereby the galaxies convert most of their available gas into stars without the influence of major mergers and ultimately result in a dry merger. As the conditions governing compact groups are reminiscent of galaxies at intermediate redshift, we propose that HCGs are appropriate for studying galaxy evolution at z ∼ 1-2.

Original languageEnglish (US)
Pages (from-to)197-217
Number of pages21
JournalAstrophysical Journal
Volume723
Issue number1
DOIs
StatePublished - Nov 1 2010

Fingerprint

merger
galaxies
wavelength
wavelengths
space use
Hubble Space Telescope
gas
age structure
ionization
spectroscopy
dwarf galaxies
globular clusters
history
signatures
young
elliptical galaxies
star clusters
gases
star formation
bursts

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Konstantopoulos, I. S., Gallagher, S. C., Fedotov, K., Durrell, P. R., Heiderman, A., Elmegreen, D. M., ... Mulchaey, J. S. (2010). Galaxy evolution in a complex environment: A multi-wavelength study of HCG 7. Astrophysical Journal, 723(1), 197-217. https://doi.org/10.1088/0004-637X/723/1/197
Konstantopoulos, I. S. ; Gallagher, S. C. ; Fedotov, K. ; Durrell, P. R. ; Heiderman, A. ; Elmegreen, D. M. ; Charlton, Jane Camilla ; Hibbard, J. E. ; Tzanavaris, P. ; Chandar, R. ; Johnson, K. E. ; Maybhate, A. ; Zabludoff, A. E. ; Gronwall, Caryl Ann ; Szathmary, D. ; Hornschemeier, A. E. ; English, J. ; Whitmore, B. ; Mendes De Oliveira, C. ; Mulchaey, J. S. / Galaxy evolution in a complex environment : A multi-wavelength study of HCG 7. In: Astrophysical Journal. 2010 ; Vol. 723, No. 1. pp. 197-217.
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Konstantopoulos, IS, Gallagher, SC, Fedotov, K, Durrell, PR, Heiderman, A, Elmegreen, DM, Charlton, JC, Hibbard, JE, Tzanavaris, P, Chandar, R, Johnson, KE, Maybhate, A, Zabludoff, AE, Gronwall, CA, Szathmary, D, Hornschemeier, AE, English, J, Whitmore, B, Mendes De Oliveira, C & Mulchaey, JS 2010, 'Galaxy evolution in a complex environment: A multi-wavelength study of HCG 7', Astrophysical Journal, vol. 723, no. 1, pp. 197-217. https://doi.org/10.1088/0004-637X/723/1/197

Galaxy evolution in a complex environment : A multi-wavelength study of HCG 7. / Konstantopoulos, I. S.; Gallagher, S. C.; Fedotov, K.; Durrell, P. R.; Heiderman, A.; Elmegreen, D. M.; Charlton, Jane Camilla; Hibbard, J. E.; Tzanavaris, P.; Chandar, R.; Johnson, K. E.; Maybhate, A.; Zabludoff, A. E.; Gronwall, Caryl Ann; Szathmary, D.; Hornschemeier, A. E.; English, J.; Whitmore, B.; Mendes De Oliveira, C.; Mulchaey, J. S.

In: Astrophysical Journal, Vol. 723, No. 1, 01.11.2010, p. 197-217.

Research output: Contribution to journalArticle

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T2 - A multi-wavelength study of HCG 7

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AU - Gallagher, S. C.

AU - Fedotov, K.

AU - Durrell, P. R.

AU - Heiderman, A.

AU - Elmegreen, D. M.

AU - Charlton, Jane Camilla

AU - Hibbard, J. E.

AU - Tzanavaris, P.

AU - Chandar, R.

AU - Johnson, K. E.

AU - Maybhate, A.

AU - Zabludoff, A. E.

AU - Gronwall, Caryl Ann

AU - Szathmary, D.

AU - Hornschemeier, A. E.

AU - English, J.

AU - Whitmore, B.

AU - Mendes De Oliveira, C.

AU - Mulchaey, J. S.

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Konstantopoulos IS, Gallagher SC, Fedotov K, Durrell PR, Heiderman A, Elmegreen DM et al. Galaxy evolution in a complex environment: A multi-wavelength study of HCG 7. Astrophysical Journal. 2010 Nov 1;723(1):197-217. https://doi.org/10.1088/0004-637X/723/1/197