Herschel-atlas: A binary HyLIRG pinpointing a cluster of starbursting protoellipticals

R. J. Ivison, A. M. Swinbank, Ian Smail, A. I. Harris, R. S. Bussmann, A. Cooray, P. Cox, H. Fu, A. Kovács, M. Krips, D. Narayanan, M. Negrello, R. Neri, J. Peñarrubia, J. Richard, D. A. Riechers, K. Rowlands, J. G. Staguhn, T. A. Targett, S. AmberAndrew Baker, N. Bourne, F. Bertoldi, M. Bremer, J. A. Calanog, D. L. Clements, H. Dannerbauer, A. Dariush, G. De Zotti, L. Dunne, S. A. Eales, D. Farrah, S. Fleuren, A. Franceschini, J. E. Geach, R. D. George, J. C. Helly, R. Hopwood, E. Ibar, M. J. Jarvis, J. P. Kneib, S. Maddox, A. Omont, D. Scott, S. Serjeant, M. W.L. Smith, M. A. Thompson, E. Valiante, I. Valtchanov, J. Vieira, P. Van Der Werf

Research output: Contribution to journalArticle

95 Scopus citations

Abstract

Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across an ≈100 kpc region - a cluster of starbursting protoellipticals. Via subarcsecond interferometric imaging we have measured accurate gas and star formation surface densities. The two brightest galaxies span ∼3 kpc FWHM in submillimeter/radio continuum and CO J = 4-3, and double that in CO J = 1-0. The broad CO line is due partly to the multitude of constituent galaxies and partly to large rotational velocities in two counter-rotating gas disks - a scenario predicted to lead to the most intense starbursts, which will therefore come in pairs. The disks have M dyn of several × 1011 M o, and gas fractions of ∼40%. Velocity dispersions are modest so the disks are unstable, potentially on scales commensurate with their radii: these galaxies are undergoing extreme bursts of star formation, not confined to their nuclei, at close to the Eddington limit. Their specific star formation rates place them ≳ 5 × above the main sequence, which supposedly comprises large gas disks like these. Their high star formation efficiencies are difficult to reconcile with a simple volumetric star formation law. N-body and dark matter simulations suggest that this system is the progenitor of a B(inary)-type ≈1014.6- o cluster.

Original languageEnglish (US)
Article number137
JournalAstrophysical Journal
Volume772
Issue number2
DOIs
StatePublished - Aug 1 2013

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • galaxies: high-redshift
  • galaxies: starburst
  • infrared: galaxies
  • radio continuum: galaxies
  • radio lines: galaxies
  • submillimeter: galaxies

Cite this

Ivison, R. J., Swinbank, A. M., Smail, I., Harris, A. I., Bussmann, R. S., Cooray, A., Cox, P., Fu, H., Kovács, A., Krips, M., Narayanan, D., Negrello, M., Neri, R., Peñarrubia, J., Richard, J., Riechers, D. A., Rowlands, K., Staguhn, J. G., Targett, T. A., ... Van Der Werf, P. (2013). Herschel-atlas: A binary HyLIRG pinpointing a cluster of starbursting protoellipticals. Astrophysical Journal, 772(2), [137]. https://doi.org/10.1088/0004-637X/772/2/137