J/MNRAS/513/1254 Red and control X-shooter QSO composites (Fawcett+, 2022)
Fundamental differences in the properties of red and blue quasars:
measuring the reddening and accretion properties with X-shooter.
Fawcett V.A., Alexander D.M., Rosario D.J., Klindt L., Lusso E.,
Morabito L.K., Calistro Rivera G.
<Mon. Not. R. Astron. Soc. 513, 1254-1274 (2022)>
=2022MNRAS.513.1254F 2022MNRAS.513.1254F (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Spectroscopy
Keywords: accretion - accretion discs - galaxies: active - galaxies: evolution -
quasars: emission lines - quasars: general
Abstract:
We have recently found fundamental differences in the radio properties
of red quasars when compared to typical blue quasars. In this paper we
use data from the X-shooter spectrograph on the Very Large Telescope,
providing spectral coverage from ∼3000-25000Å, of a sample of 40
red and blue luminous quasars at 1.45<z<1.65 to explore the
connections between the radio, emission-line, and accretion-disc
properties. We fit various dust-extinction curves to the data and find
that dust reddening can fully explain the observed colours for the
majority of the red quasars in our sample, with moderate extinctions
ranging from AV∼0.06-0.7mags. We confront our spectra with a simple
thin accretion-disc model and find this can describe the continua of
both the blue and red quasars, once corrected for dust extinction; we
also find no significant differences in the accretion properties. We
detect ionized outflows in a number of red and blue quasars, but do
not find any significant evidence that they are more prevalent in the
red quasar population. Overall our findings imply that the radio
emission is more closely connected to circumnuclear/ISM opacity rather
than accretion disc or outflow differences.
Description:
VLT/X-shooter spectral composites for a sample of 12 red QSOs and 28
control QSOs, as described in the paper. Composites span a rest
wavelength of 1250-9000Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
red-spec.dat 60 9810 Red QSO VLT/X-shooter composite
con-spec.dat 60 9810 Control QSO VLT/X-shooter composite
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Byte-by-byte Description of file: red-spec.dat con-spec.dat
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Bytes Format Units Label Explanations
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1- 18 F18.13 0.1nm lambda Rest wavelength array for composite
20- 39 F20.17 --- Flux Flux normalized at 6000Å (1)
41- 60 F20.17 --- e_Flux Error relative to the normalized flux
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Note (1): Consistuent spectra are corrected for galactic extinction using their
coordinates and the extinctions map from
http://irsa.ipac.caltech.edu/applications/DUST/
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Acknowledgements:
Victoria Fawcett, victoria.fawcett(at)durham.ac.uk
(End) Patricia Vannier [CDS] 31-Mar-2022