J/A+A/650/A84 QSO type 2 VLA images (Villar-Martin+, 2021)
Interactions between large-scale radio structures and gas in a sample of
optically selected type 2 quasars.
Villar-Martin M., Emonts B.H.C., Cabrera Lavers A., Bellocchi E.,
Alonso Herrero A., Humphrey A., Dall'Agnol de Oliveira B.,
Storchi-Bergmann T.
<Astron. Astrophys. 650, A84 (2021)>
=2021A&A...650A..84V 2021A&A...650A..84V (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Radio sources
Keywords: quasars: general - galaxies: jets - galaxies: active -
galaxies: evolution
Abstract:
The role of radio mode feedback in non radio-loud quasars needs to be
explored in depth to determine its true importance. Its effects can be
identified based on the evidence of interactions between the radio
structures and the ambient ionised gas.
We investigate this in a sample of 13 optically selected type-2
quasars (QSO2) at z<0.2 with Very Large Array (VLA) FIRST Survey
radio detections. None are radio loud. The ranges of
[OIII]c1lλ5007 and monochromatic radio luminosities are
log(L[OIII]=erg/s)∼42.08-42.79 and
log(P1.4GHz/erg/s/Hz)∼30.08-31.76. All show complex optical
morphologies, with signs of distortion across tens of kpc due to
mergers/interactions.
We have searched for evidence of interactions between the radio
structures and the ionised gas by characterising and comparing their
morphologies. The first is traced by narrow band H images obtained
with the GTC 10.4m Spanish telescope and the Osiris instrument. The
second is traced by VLA radio maps obtained with A and B
configurations to achieve both high resolution and brightness
sensitivity.
The radio luminosity has an active galatic nucleus (AGN) component in
11/13 QSO2, which is spatially extended in our radio data in 9 of them
(jets/lobes/other). The relative contribution of the extended radio
emission to the total P1.4GHz is in most cases in the range 30% to
90%. The maximum sizes are in the range dRmax∼few-500kpc. QSO2
undergoing interaction/merger events appear to be invariably
associated with ionised gas spread over large spatial scales with
maximum distances from the AGN in the range rmax∼12-90kpc. The
morphology of the ionised gas at <30kpc is strongly influenced by AGN
related processes.
Evidence for radio-gas interactions exist in 10/13 QSO2; that is, all
but one with confirmed AGN radio components. The interactions are
identified across different spatial scales, from the nuclear narrow
line region up to tens of kpc.
Although this sample cannot be considered representative of the
general population of QSO2, it supports the idea that large scale
low/modest power radio sources can exist in radio-quiet QSO2, which
can provide a source of feedback on scales of the spheroidal component
of galaxies and well into the circumgalactic medium, in systems where
radiative mode feedback is expected to dominate.
Description:
The VLA sample consists of 12 objects from the SDSS catalogue of QSO2
at z<0.2 by Reyes et al. (2008, Cat. J/AJ/136/2373) (Table 1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 13 The sample general properties
list.dat 109 48 List of fits images
fits/* . 48 Individual fits images
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See also:
J/AJ/136/2373 : Type 2 quasars from SDSS (Reyes+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Source Source name
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 20 F5.2 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 38 F5.3 --- z Redshift
40- 44 F5.3 kpc/arcsec Scale Scale
46- 50 F5.2 [-] log(L[OIII]) Luminosity of [OIII]5007 line
52- 56 F5.2 [10-7W/Hz] log(P1.4GHz) Monochromatic luminosity at 1.4GHz
inferred from the NVSS flux
58- 61 F4.2 --- q ?=- Quantitative measure of the
FIR/radio flux-density ratio (1)
63- 66 F4.2 --- e_q ? rms uncertainty on q
68- 71 A4 ---- Class [RQ/I ] Classification (2)
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Note (1): q≤1.8, suggests that the the radio flux has a significant AGN
contribution (see text).
Note (2): Classification code as follows:
RQ = radio quiet (RQ) or
RI = radio intermediate (RI)
RQ/I = ambiguous classification of several targets reflects the vague
division between classes
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 52 A23 "datime" Obs.date Observation date
54- 60 F7.5 GHz Freq ? Observed frequency
62- 66 I5 Kibyte size Size of FITS file
68-109 A42 --- FileName Name of FITS file, in subdirectory fits
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Acknowledgements:
Montserrat Villar Martin, villarmm(at)cab.inta-csic.es
(End) Patricia Vannier [CDS] 02-Jun-2021