Star formation rates in luminous quasars at 2 < z < 3
File(s)MNRAS-2016-Harris-4179-94.pdf (1.47 MB)
Published version
Author(s)
Type
Journal Article
Abstract
We investigate the relation between star formation rates (M˙sM˙s) and AGN properties in optically selected type 1 quasars at 2 < z < 3 using data from Herschel and the SDSS. We find that M˙sM˙s remains approximately constant with redshift, at 300 ± 100 M⊙ yr−1. Conversely, M˙sM˙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 M˙sM˙s and black hole accretion rate (M˙bhM˙bh) existing in only parts of the z−M˙s−M˙bhz−M˙s−M˙bh plane, dependent on the free gas fraction, the trigger for activity, and the processes that may quench star formation. The relations between M˙sM˙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 M˙sM˙s and M˙bhM˙bh. Finally, there is no strong relation between M˙sM˙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.
Date Issued
2016-04-21
Date Acceptance
2016-02-02
Citation
Monthly Notices of the Royal Astronomical Society, 2016, 457 (4), pp.4179-4194
ISSN
1365-2966
Publisher
Oxford University Press (OUP)
Start Page
4179
End Page
4194
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
457
Issue
4
Copyright Statement
© 2016 The Authors
Published by Oxford University Press on behalf of the Royal Astronomical Society
Published by Oxford University Press on behalf of the Royal Astronomical Society
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/K001051/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
galaxies: evolution
quasars: general
galaxies: starburst
galaxies: star formation
infrared: galaxies
ACTIVE GALACTIC NUCLEI
SPECTRAL ENERGY-DISTRIBUTIONS
DIGITAL-SKY-SURVEY
BLACK-HOLE ACCRETION
SDSS STRIPE 82
OSCILLATION SPECTROSCOPIC SURVEY
ULTRALUMINOUS INFRARED GALAXIES
SUBMILLIMETER NUMBER COUNTS
RADIATIVE-TRANSFER MODELS
EMISSION-LINE PROPERTIES
Publication Status
Published