J/MNRAS/495/3943 Hard-X-ray-selected AGNs I (Chiaraluce+, 2020)
Hard-X-ray-selected active galactic nuclei.
I. A radio view at high frequencies.
Chiaraluce E., Panessa F., Bruni G., Baldi R.D., Behar E., Vagnetti F.,
Tombesi F., McHardy I.
<Mon. Not. R. Astron. Soc., 495, 3943-3960 (2020)>
=2020MNRAS.495.3943C 2020MNRAS.495.3943C (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; Interferometry ;
Radio sources ; X-ray sources
Keywords: techniques: interferometric - galaxies: active - galaxies: nuclei -
galaxies: Seyfert - radio continuum: galaxies - X-rays: galaxies
Abstract:
A thorough study of radio emission in active galactic nuclei (AGNs) is
of fundamental importance to understand the physical mechanisms
responsible for the emission and the interplay between accretion and
ejection processes. High-frequency radio observations can target the
nuclear contribution of smaller emitting regions and are less affected
by absorption. We present JVLA 22 and 45GHz observations of 16 nearby
(0.003=<z=<0.3) hard-X-ray-selected AGNs at the (sub)-kpc scale with
tens µJy/beam sensitivity. We detected 15/16 sources, with flux
densities ranging from hundreds µJy to tens Jy (specific
luminosities from ∼1020 to ∼1025W/Hz at 22GHz). All detected
sources host a compact core, with eight being core-dominated at either
frequencies, the others exhibiting also extended structures. Spectral
indices range from steep to flat/inverted. We interpret this evidence
as either due to a core+jet system (6/15), a core accompanied by
surrounding star formation (1/15), to a jet oriented close to the line
of sight (3/15), to emission from a corona or the base of a jet
(1/15), although there might be degeneracies between different
processes. Four sources require more data to shed light on their
nature. We conclude that, at these frequencies, extended, optically
thin components are present together with the flat-spectrum core. The
LR/LX∼10-5 relation is roughly followed, indicating a possible
contribution to radio emission from a hot corona. A weakly significant
correlation between radio core (22 and 45GHz) and X-ray luminosities
is discussed in the light of an accretion-ejection framework.
Description:
The starting point of our work is the sample of 140 extragalactic
objects observed by INTEGRAL/Imager on Board the Integral Satellite
(IBIS) in the 20-40keV range (Bird et al. 2007ApJS..170..175B 2007ApJS..170..175B, Cat.
J/ApJS/170/175).
Malizia et al. (2009MNRAS.399..944M 2009MNRAS.399..944M) applied a Schmitt V/Vmax test
to the IBIS AGN with a significance threshold of ∼5σ, obtaining
a sample of 88 AGNs, which comprises 41 Seyfert-1 objects, 5
narrow-line Seyfert 1 (NLS1), 33 Seyfert-2, and 9 Blazars.
In this picture, our group has started a wide-band radio
characterization with the JVLA for the part of visible sources in our
sample, i.e. north of -30° in declination (44 sources), with a
separate characterization at high frequencies (i.e. 22 and 45GHz) and
low frequencies (i.e. 5, 10, and 15GHz), matched in resolution thanks
to the different requested JVLA configurations (C and B,
respectively).
In this work, we report observations for 16 objects out of 44, which
have been observed by the JVLA at the high frequencies K and Q (22 and
45GHz, respectively, VLA project 18B-163) in C configuration. The
reason for which only 16/44 sources have been observed is because
these sources could be observed in the VLA LST range 0-12 in which the
scheduling pressure (i.e. the number of sessions desiring per hour) is
lower.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 164 82 Imaging results for the sources in our sample
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See also:
J/ApJS/186/1 : The 4th IBIS/ISGRI soft gamma-ray survey catalog (Bird+, 2010)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Source name
16- 24 A9 --- Band Frequency band (K, Q or Q-tapered)
26- 30 I5 uJy/beam sigimage Image noise rms
32- 36 A5 --- Comp Component (only for the resolved sources)
38 A1 --- l_Ftotal Limit flag on Ftotal
40- 48 F9.3 mJy Ftotal ? Integrated flux density
50- 56 F7.2 mJy e_Ftotal ? Error on Ftotal
58 A1 --- l_Fpeak Limit flag on Fpeak
60- 68 F9.3 mJy/beam Fpeak ? Peak density
70- 76 F7.2 mJy/beam e_Fpeak ? Error on Fpeak
78 A1 --- l_thetaM Limit flag on thetaM
80- 85 F6.1 mas thetaM ? Deconvolved FWHM major axis determined
from an elliptical Gaussian fit
87- 89 I3 mas e_thetaM ? Error on thetaM
91 A1 --- l_thetam Limit flag on thetam
93- 98 F6.1 mas thetam ? Deconvolved FWHM minor axis determined
from an elliptical Gaussian fitExplain
100- 102 I3 mas e_thetam ? Error on thetam
104- 108 F5.1 deg PA ? Position angle
110- 113 F4.1 deg e_PA ? Error on PA
115- 116 I2 h RAh ? Right ascension (J2000)
118- 119 I2 min RAm ? Right ascension (J2000)
121- 127 F7.4 s RAs ? Right ascension (J2000)
129- 133 F5.3 s e_RAs ? Error on RAs
135 A1 --- DE- Declination sign (J2000)
136- 137 I2 deg DEd ? Declination (J2000)
139- 140 I2 arcmin DEm ? Declination (J2000)
142- 147 F6.3 arcsec DEs ? Declination (J2000)
149- 153 F5.3 arcsec e_DEs ? Error on DEs
155- 159 F5.2 --- alpha ? Spectral index calculated from the 22GHz
and the 45GHz naturally weighted, tapered
maps (1)
161- 164 F4.2 --- e_alpha ? Error on alpha
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Note (1): For NGC 5252 only the spectral index of the southern (core) component
is shown as the northern component is not associated with the AGN
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History:
From electronic version of the journal
References:
Panessa et al., Paper II 2022MNRAS.515..473P 2022MNRAS.515..473P
(End) Ana Fiallos [CDS] 22-Jun-2023