J/ApJ/900/L34 BL Lac objects and radio galaxies comparison (Massaro+, 2020)
Dragon's Lair: on the large-scale environment of BL Lac objects.
Massaro F., Capetti A., Paggi A., Baldi R.D., Tramacere A., Pillitteri I.,
Campana R.
<Astrophys. J., 900, L34 (2020)>
=2020ApJ...900L..34M 2020ApJ...900L..34M
ADC_Keywords: BL Lac objects; Galaxies, radio; Redshifts; Active gal. nuclei
Keywords: Relativistic jets; Astrostatistics; Active galaxies; Radio galaxies;
Galaxy clusters; BL Lacertae objects
Abstract:
The most elusive and extreme subclass of active galactic nuclei
(AGNs), known as BL Lac objects, shows features that can only be
explained as the result of relativistic effects occurring in jets
pointing at a small angle with respect to the line of sight. A
longstanding issue is the identification of the BL Lac parent
population with jets oriented at larger angles. According to the
"unification scenario" of AGNs, radio galaxies with low luminosity and
an edge-darkened radio morphology are the most promising candidate
parent population of BL Lacs. Here we compare the large-scale
environment, an orientation-independent property, of well-defined
samples of BL Lacs with samples of radio galaxies all lying in the
local universe. Our study reveals that BL Lacs and radio galaxies live
in significantly different environments, challenging predictions of
the unification scenario. We propose a solution to this problem
proving that large-scale environments of BL Lacs are statistically
consistent with those of compact radio sources, known as FR 0s, and
share similar properties. This implies that highly relativistic jets
are ubiquitous and are the natural outcome of the accretion of gas
into the deep gravitational potential well produced by supermassive
black holes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 473 Environmental parameters for all sample analyzed
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
VII/274 : The Roma BZCAT - 5th edition (Massaro+, 2015)
VIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015)
J/ApJS/167/1 : Galaxy groups and clusters from SDSS (Berlind+, 2006)
J/ApJS/171/61 : All-Sky Survey of Flat-Spectrum Radio Sources (Healey+, 2007)
J/ApJ/752/61 : Blazars in unidentified γ-ray sources (Massaro+, 2012)
J/ApJ/748/68 : WISE IR colors of gamma-ray blazars (D'Abrusco+, 2012)
J/ApJ/752/61 : Blazars in unidentified γ-ray sources (Massaro+, 2012)
J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)
J/MNRAS/442/1693 : Gamma-ray-loud blazars opt. polarization (Pavlidou+, 2014)
J/A+A/598/A49 : FRICAT. FIRST cat. of FR I radio galaxies (Capetti+, 2017)
J/A+A/601/A81 : FIRST catalog of FR II radio galaxies (Capetti+, 2017)
J/A+A/609/A1 : FR0CAT. a FIRST cat. of FR 0 radio galaxies (Baldi+, 2018)
J/ApJ/878/11 : Type 1 vs 2 X-ray-selected COSMOS AGNs & env. (Zou+, 2019)
J/ApJS/247/33 : Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
J/ApJS/247/71 : Large-scale environment of radio gal. II. (Massaro+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Sample Sample (1)
6- 28 A23 --- Name Source name
30- 31 I2 h RAh Hour of Right Ascension (J2000)
33- 34 I2 min RAm Minute of Right Ascension (J2000)
36- 40 F5.2 s RAs Second of Right Ascension (J2000)
42- 42 A1 --- DE- Sign of the Declination (J2000)
43- 44 I2 deg DEd Degree of Declination (J2000)
46- 47 I2 arcmin DEm Arcminute of Declination (J2000)
49- 53 F5.2 arcsec DEs Arcsecond of Declination (J2000)
55- 61 F7.5 --- z [0.01/0.15] Source redshift
63- 68 F6.4 --- dz [0/0.005] Redshift offset (2)
70- 76 F7.2 kpc dproj [0/1891] Projected separation (3)
78- 81 F4.1 --- N500 [0/38] Number of cosmological neighbors
within 500kpc
83- 86 F4.1 --- N1000 [0/92] Number of cosmological neighbors
within 1000kpc
88- 92 F5.1 --- N2000 [0/164] Number of cosmological neighbors
within 2000kpc
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Note (1): Samples as follows:
BZB = BL Lac objects mainly from Massaro+, 2015, VII/274 (See Section 2;
14 occurrences);
BZG = BL Lacs-galaxy dominated from Massaro+, 2015, VII/274
(41 occurrences);
FR0 = Core-dominated compact radio galaxies of FR0 type from
Baldi+, 2018, J/A+A/609/A1 (108 occurrences);
LERG = Low excitation radio galaxies from Capetti+ 2017, J/A+A/601/A81 or
J/A+A/598/A49 (310 occurrences).
Note (2): Difference between the average redshift of cosmological neighbors
in 2Mpc and that of the central source.
Note (3): Physical distance between the central RG and the average position of
cosmological neighbors within 2Mpc, computed at z.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Jan-2022