J/A+A/630/A110 SDSS-FIRST quasar sample study (Ganci+, 2019)
Radio-loudness along the quasar main sequence.
Ganci V., Marziani P., D'Onofrio M., del Olmo A., Bon E., Bon N.,
Negrete C.A.
<Astron. Astrophys. 630, A110 (2019)>
=2019A&A...630A.110G 2019A&A...630A.110G (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Active gal. nuclei ; Radio sources ; Redshifts
Keywords: Galaxy: evolution - quasars: general - quasars: emission lines -
quasars: supermassive black holes - accretion, accretion disks -
galaxies: jets
Abstract:
When can an active galactic nucleus (AGN) be considered radio-loud?
Following the established view of the AGNs inner workings, an AGN is
radio-loud if associated with relativistic ejections emitting a radio
synchrotron spectrum (i.e., it is a "jetted" AGN). In this paper
we exploit the AGN main sequence that offers a powerful tool to
contextualize radio properties.
If large samples of optically-selected quasars are considered, AGNs
are identified as radio-loud if their Kellermann's radio loudness
ratio RK>10. Our aims are to characterize the optical properties
of different classes based on radioloudness within the main sequence
and to test whether the condition RK>10 is sufficient for the
identification of RL AGNs, since the origin of relatively strong radio
emission may not be necessarily due to relativistic ejection.
A sample of 355 quasars was selected by cross-correlating the FIRST
survey with the SDSS DR14 quasar catalog. We classified the optical
spectra according to their spectral types along the main sequence of
quasars. For each spectral type, we distinguished compact and extended
morphology (providing a FIRST-based atlas of radio maps in the latter
case), and three classes of radio-loudness: detected (specific flux
ratio in the g band and at 1.4GHz, RK'<10), intermediate
(10RK'<70), and radio loud (RK'≥70).
The analysis revealed systematic differences between radio-detected
(i.e., radio-quiet), radio-intermediate, and radio-loud in each
spectral type along the main sequence. We show that spectral bins that
contain the extreme Population A sources have radio power compatible
with emission by mechanisms ultimately due to star formation
processes. Radio-loud sources of Population B are characteristically
jetted. Their broad Hβ profiles can be interpreted as due to a
binary broad-line region. We suggest that RL Population B sources
should be preferential targets for the search of black hole binaries,
and present a sample of binary black hole AGN candidates.
The validity of the Kellermann's criterion may be dependent on the
source location along the quasar main sequence. The consideration of
the MS trends allowed to distinguish between sources whose radio
emission mechanisms is "jetted" from the ones where the mechanism
is likely to be fundamentally different.
Description:
The AGNs studied in this work were selected from the twelfth release
of the Sloan Digital Sky Survey (SDSS) Quasar Catalog published in
2017 (Paris et al., 2017A&A...597A..79P 2017A&A...597A..79P, Cat. VII/279). The selected
objects have an i-band magnitude mi value below 19.5 and a Baryon
Oscillation Spectroscopic Survey (BOSS, Dawson et al.,
2013AJ....145...10D 2013AJ....145...10D) pipeline redshift value z≲1.0.
Photometric and spectroscopic parameters for 355 low redshift Type-1
Active galactic nuclei (AGNs) are presented. For each AGN the
following parameters are given: SDSS identification, redshift, g-band
specific flux density, 1.4GHz peak specific flux density (only for
core- dominated, CD, sources), 1.4GHz integrated specific flux
density (only for source for which the integrated specific flux
density is higher of 10% than the peak specific flux density), decimal
logarithm of Kellerman's parameter, decimal logarithm of luminosity at
5100 Angstrom, decimal logarithm of 1.4 GHz radio power (for FRII the
radio power is the sum of the lobes and core radio power), FWHM of
Hbeta, ratio of the integrated flux of the FeII λ 4570 blend of
multiplets and that of the Hbeta full broad component (R_FeII), and a
classification code. Moreover, for FRII the following parameters are
given: right ascension and declination (J2000) of the SDSS AGN (the
core) and that of the two lobes, the separations of the lobes to the
core, and the angle between the lobes as seen from the SDSS AGN
position. The derivation of the effective parameters takes the
K-correction and g-band galactic extinction into account.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 102 289 CD AGNs sample
tablea2.dat 91 66 FRII coordinates
tablea3.dat 88 66 FRII parameters
--------------------------------------------------------------------------------
See also:
VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- SDSS SDSS identification (JHHMMSS.ss+DDMMSS.s)
21- 28 F8.6 --- z Redshift
30- 35 F6.4 mJy Fg g-band specific flux density
37- 46 F10.5 mJy Fpeak1.4 1.4GHz peak specific flux density
48- 56 F9.4 mJy Fint1.4 ?=- 1.4GHz integrated specific flux density
58- 62 F5.2 [-] logRK Decimal log. of Kellerman's parameter
64- 68 F5.2 [10-7W] logL5100 Decimal logarithm of luminosity at 5100Å
70- 74 F5.2 [W/s] logP14 Decimal log. of 1.4 GHz radio power
76- 82 F7.1 km/s FWHMHb Full width half maximum of Hβ
85 A1 --- l_RFeII Limit flag on RFeII
86- 88 F3.1 --- RFeII Ratio of the integrated flux of the FeII
λ4570 blend of multiplets and that of
the Hβ full broad component.
90-100 A11 --- Class Classification code
102 A1 --- Note [*] * indicates a note (1)
--------------------------------------------------------------------------------
Note (1): Indivudal notes as follows:
J083928.53+260614.3: 4C+49.22, extended emission plus very bright
unresolved core with optical/X jet (Fernini, 2014ApJS..212...19F 2014ApJS..212...19F);
flat spectrum and gamma-ray detection (Cutini et al.,
2014MNRAS.445.4316C 2014MNRAS.445.4316C).
J111018.12+104619.5: strong unresolved radio core with faint emission;
X-ray source (Zickgraf et al., 2003, Cat. J/A+A/406/535).
J103346.39+233220.0: Bright core with symmetric extension.
J114746.20+622214.5: Core with faint extension to the west.
J115324.46+493108.7: Hybrid morphology (Gawronski et al.,
2006A&A...447...63G 2006A&A...447...63G); bright core with flat spectrum
(Munoz et al., 2003ApJ...594..684M 2003ApJ...594..684M).
J124511.25+335610.1: Bright core with faint extension at PA=145.
J134751.58+283629.7: Bright core with symmetric extension.
J150725.62+112635.6: Bright core of almost compact appearance.
J152039.69+421111.1: Bright, elongated core with faint diffuse emission.
-------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- SDSS SDSS identification (JHHMMSS.ss+DDMMSS.s)
21- 28 F8.4 deg RAdeg Core right ascension (J2000)
31- 37 F7.4 deg DEdeg Core declination (J2000)
39- 46 F8.4 deg RA1deg 1 lobe right ascension (J2000)
48- 54 F7.4 deg DE1deg 1 lobe declination (J2000)
56- 60 F5.2 arcsec Sep1 1 lobe separation from core
62- 69 F8.4 deg RA2deg 2 lobe right ascension (J2000)
72- 78 F7.4 deg DE2deg 2 lobe declination (J2000)
80- 85 F6.2 arcsec Sep2 2 lobe separation from core
87- 91 F5.1 deg Angle Opening angle between the 2 lobes as
seen from the SDSS core
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- SDSS SDSS identification (JHHMMSS.ss+DDMMSS.s)
21- 28 F8.6 --- z Redshift
30- 35 F6.4 mJy Fg g-band specific flux density
37- 43 F7.2 mJy Fint1.4 1.4GHz integrated specific flux density
45- 48 F4.2 [-] logRK Decimal logarithm of Kellerman's parameter
50- 54 F5.2 [10-7W] logL5100 Decimal logarithm of luminosity at 5100Å
56- 60 F5.2 [W/s] logP1.4 decimal log. of 1.4GHz radio power
62- 69 F8.2 km/s FWHMHb Full width half maximum of Hβ
71 A1 --- l_RFeII Limit flag on RFeII
72- 74 F3.1 --- RFeII Ratio of the integrated flux of the
FeII λ4570 blend of multiplets
and that of the Hβ full broad component
76- 88 A13 --- Class Classification code
--------------------------------------------------------------------------------
Acknowledgements:
Valerio Ganci, valerio.ganci(at)gmail.com
(End) Valerio Ganci [Koeln, Germany], Patricia Vannier [CDS] 27-Aug-2019