Bibcode
Harris, K.; Farrah, Duncan; Schulz, Bernhard; Hatziminaoglou, Evanthia; Viero, Marco; Anderson, Nick; Béthermin, Matthieu; Chapman, Scott; Clements, David L.; Cooray, Asantha; Efstathiou, Andreas; Feltre, Anne; Hurley, Peter; Ibar, Eduardo; Lacy, Mark; Oliver, Sebastian; Page, Mathew J.; Pérez-Fournon, I.; Petty, Sara M.; Pitchford, Lura K.; Rigopoulou, Dimitra; Scott, Douglas; Symeonidis, Myrto; Vieira, Joaquin; Wang, Lingyu
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 457, Issue 4, p.4179-4194
Advertised on:
4
2016
Citations
51
Refereed citations
50
Description
We investigate the relation between star formation rates (dot{{M}}_s)
and AGN properties in optically selected type 1 quasars at 2 < z <
3 using data from Herschel and the SDSS. We find that dot{{M}}_s remains
approximately constant with redshift, at 300 ± 100
M⊙ yr-1. Conversely, dot{{M}}_s increases with
AGN luminosity, up to a maximum of ˜ 600 M⊙
yr-1, and with C IV FWHM. In context with previous results,
this is consistent with a relation between dot{{M}}_s and black hole
accretion rate (dot{{M}}_{bh}) existing in only parts of the
z-dot{{M}}s-dot{{M}}_{bh} plane, dependent on the free gas
fraction, the trigger for activity, and the processes that may quench
star formation. The relations between dot{{M}}_s and both AGN luminosity
and C IV FWHM are consistent with star formation rates in quasars
scaling with black hole mass, though we cannot rule out a separate
relation with black hole accretion rate. Star formation rates are
observed to decline with increasing C IV equivalent width. This decline
can be partially explained via the Baldwin effect, but may have an
additional contribution from one or more of three factors; Mi
is not a linear tracer of L2500, the Baldwin effect changes
form at high AGN luminosities, and high C IV EW values signpost a change
in the relation between dot{{M}}_s and dot{{M}}_{bh}. Finally, there is
no strong relation between dot{{M}}_s and Eddington ratio, or the
asymmetry of the C IV line. The former suggests that star formation
rates do not scale with how efficiently the black hole is accreting,
while the latter is consistent with C IV asymmetries arising from
orientation effects.