Open AccessThe K ‐band Hubble diagram of submillimetre galaxies and hyperluminous galaxies
Author(s) -
Serjeant Stephen,
Farrah Duncan,
Geach James,
Takagi Toshinobu,
Verma Aprajita,
Kaviani Ali,
Fox Matt
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2003.07305.x
Subject(s) - physics , astrophysics , luminous infrared galaxy , radio galaxy , peculiar galaxy , astronomy , elliptical galaxy , galaxy , redshift , galaxy formation and evolution , galaxy group
We present the K ‐band Hubble diagrams ( K – z relations) of submillimetre‐selected galaxies and hyperluminous galaxies (HLIRGs). We report the discovery of a remarkably tight K – z relation of HLIRGs, indistinguishable from that of the most luminous radio galaxies. Like radio galaxies, the HLIRG K – z relation at z ≲ 3 is consistent with a passively evolving ∼3 L * instantaneous starburst starting from a redshift of z ∼ 10 . In contrast, many submillimetre‐selected galaxies are ≳2 mag fainter, and the population has a much larger dispersion. We argue that dust obscuration and/or a larger mass range may be responsible for this scatter. The galaxies so far proved to be hyperluminous may have been biased towards higher AGN bolometric contributions than submillimetre‐selected galaxies due to the 60‐μm selection of some, so the location on the K – z relation may be related to the presence of the most massive active galactic nucleus. Alternatively, a particular host galaxy mass range may be responsible for both extreme star formation and the most massive active nuclei.