151. Extreme submillimetre starburst galaxies
- Author
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Duncan Farrah, David L. Clements, W. J. Pearson, Michael Rowan-Robinson, Lingyu Wang, Lucia Marchetti, Carlotta Gruppioni, Dimitra Rigopoulou, Mattia Vaccari, Astronomy, Kapteyn Astronomical Institute, ITA, USA, GBR, NLD, ZAF, Science and Technology Facilities Council (STFC), and Imperial College Trust
- Subjects
Hubble Deep Field ,galaxies: starburst ,Astrophysics ,01 natural sciences ,RADIO OBSERVATIONS ,Astrophysics::Solar and Stellar Astrophysics ,DEEP-FIELD ,NUMBER COUNTS ,010303 astronomy & astrophysics ,HYPERLUMINOUS INFRARED GALAXIES ,Physics ,FORMING GALAXIES ,quasars: supermassive black holes ,Physical Sciences ,Spectral energy distribution ,Astrophysics::Earth and Planetary Astrophysics ,galaxies: evolution ,ACTIVE GALACTIC NUCLEI ,Active galactic nucleus ,Stellar mass ,astro-ph.GA ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,SPECTRAL ENERGY-DISTRIBUTIONS ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astronomy & Astrophysics ,STAR-FORMATION RATES ,HIGH-REDSHIFT GALAXIES ,infrared: galaxies ,EXTRAGALACTIC SURVEY ,0103 physical sciences ,STAR-FORMING GALAXIES ,quasars: supermassive black holes galaxies: starburst ,Astrophysics::Galaxy Astrophysics ,Luminous infrared galaxy ,Science & Technology ,010308 nuclear & particles physics ,Star formation ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Redshift ,Galaxy ,0201 Astronomical And Space Sciences ,Space and Planetary Science ,LUMINOSITY FUNCTION ,Astrophysics of Galaxies (astro-ph.GA) ,galaxies: star formation ,cosmology: observations ,DEEP-FIELD-SOUTH ,FORMATION RATE DENSITY ,HIGH-REDSHIFT ,COSMOLOGY LEGACY SURVEY - Abstract
We use two catalogues, a Herschel catalogue selected at 500 mu (HerMES) and an IRAS catalogue selected at 60 mu (RIFSCz), to contrast the sky at these two wavelengths. Both surveys demonstrate the existence of extreme starbursts, with star-formation rates (SFRs) > 5000 Msun/yr. The maximum intrinsic star-formation rate appears to be ~30,000 Msun/yr. The sources with apparent SFR estimates higher than this are in all cases either lensed systems, blazars, or erroneous photometric redshifts. At redshifts of 3 to 5, the time-scale for the Herschel galaxies to make their current mass of stars at their present rate of formation ~ 10^8 yrs, so these galaxies are making a significant fraction of their stars in the current star-formation episode. Using dust mass as a proxy for gas mass, the Herschel galaxies at redshift 3 to 5 have gas masses comparable to their mass in stars. Of the 38 extreme starbursts in our Herschel survey for which we have more complete SED information, over 50% show evidence for QSO-like optical emission, or exhibit AGN dust tori in the mid-infrared SEDs. In all cases however the infrared luminosity is dominated by a starburst component. We derive a mean covering factor for AGN dust as a function of redshift and derive black hole masses and black hole accretion rates. There is a universal ratio of black-hole mass to stellar mass, ~ 10^{-3}, driven by the strong period of star-formation and black-hole growth at z = 1-5., 21 pages, 15 figures, accepted for publication in Astronomy and Astrophysics
- Published
- 2017