J/MNRAS/477/830 Radio flux density of extremely red quasars (Hwang+, 2018)
Winds as the origin of radio emission in z = 2.5 radio-quiet extremely red
quasars.
Hwang H.-C., Zakamska N.L., Alexandroff R.M., Hamann F., Greene J.E.,
Perrotta S., Richards G.T.
<Mon. Not. R. Astron. Soc., 477, 830-844 (2018)>
=2018MNRAS.477..830H 2018MNRAS.477..830H (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Radio sources
Keywords: galaxies: active - quasars: general - radio continuum: galaxies
Abstract:
Most active galactic nuclei (AGNs) are radio quiet, and the origin of
their radio emission is not well understood. One hypothesis is that
this radio emission is a byproduct of quasar-driven winds. In this
paper, we present the radio properties of 108 extremely red quasars
(ERQs) at z=2-4. ERQs are among the most luminous quasars
(Lbol∼1047-48erg/s^) in the Universe, with signatures of extreme
(≫1000km/s) outflows in their [OIII]λ5007Å emission,
making them the best subjects to seek the connection between radio and
outflow activities. All ERQs but one are unresolved in the radio on
∼10kpc scales, and the median radio luminosity of ERQs is
νLν[6GHz]= 1041.0erg/s, in the radio-quiet regime, but 1-2
orders of magnitude higher than that of other quasar samples. The
radio spectra are steep, with a mean spectral index <α≥-1.0. In
addition, ERQs neatly follow the extrapolation of the low-redshift
correlation between radio luminosity and the velocity dispersion of
[OIII]-emitting ionized gas. Uncollimated winds, with a power of one
per cent of the bolometric luminosity, can account for all these
observations. Such winds would interact with and shock the gas around
the quasar and in the host galaxy, resulting in acceleration of
relativistic particles and the consequent synchrotron emission
observed in the radio. Our observations support the picture in which
ERQs are signposts of extremely powerful episodes of quasar feedback,
and quasar-driven winds as a contributor of the radio emission in the
intermediate regime of radio luminosity
νLν=1039-1042erg/s.
Description:
We present radio follow-up observations of 101 extremely red quasars
(ERQs) with VLA which we combine with detections in the FIRST survey.
The observations were carried out using the VLA B configuration in the
C band (∼4-8GHz; Program 16A-108, PI: Zakamska), which provides
a resolution of 1.3-arcsec, or ∼10kpc at z=2.5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 54 101 Radio flux densities and luminosities of
extremely red quasars (ERQs)
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See also:
VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)
J/MNRAS/464/3431 : Extremely red quasars in BOSS (Hamann+, 2017)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- SDSS SDSS name (SDSS JHHMMSS.ss+DDMMSS.s)
26- 29 A4 --- Type ERQ type (1)
31- 35 F5.3 --- z Emission-line redshift from DR12Q
37 A1 --- l_F6.2GHz Limit flag on F6.2GHz
38- 41 I4 uJy F6.2GHz Flux density observed at 6.2GHz
43- 44 I2 uJy e_F6.2GHz ?=0 rms uncertainty on flux density (2)
46 A1 --- l_Lradio Limit flag on Lradio
47- 54 E8.3 10-7W Lradio Radio luminosity at rest-frame 6GHz
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Note (1): ERQ type as follows:
like = sources are ERQ-like objects in both Hamann et al.
(2017MNRAS.464.3431H 2017MNRAS.464.3431H, Cat. J/MNRAS/464/3431)
main = sources are refer to ERQs in this paper
Note (2): 0 for non-detections
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-May-2021