J/ApJ/726/16 γ-ray loud blazars (Linford+, 2011)
Characteristics of gamma-ray loud blazars in the VLBA imaging and
polarimetry survey.
Linford J.D., Taylor G.B., Romani R.W., Healey S.E., Helmboldt J.F.,
Readhead A.C.S., Reeves R., Richards J.L., Cotter G.
<Astrophys. J., 726, 16 (2011)>
=2011ApJ...726...16L 2011ApJ...726...16L
ADC_Keywords: Active gal. nuclei ; BL Lac objects ; Galaxies, radio ;
Gamma rays ; QSOs ; Cross identifications ; Redshifts
Keywords: galaxies: active - galaxies: jets - galaxies: nuclei -
gamma rays: galaxies - radio continuum: galaxies
Abstract:
The radio properties of blazars detected by the Large Area Telescope
(LAT) on board the Fermi Gamma-ray Space Telescope have been observed
as part of the VLBA Imaging and Polarimetry Survey. This large,
flux-limited sample of active galactic nuclei (AGNs) provides insights
into the mechanism that produces strong γ-ray emission. At lower
flux levels, radio flux density does not directly correlate with
γ-ray flux. We find that the LAT-detected BL Lac objects tend to
be similar to the non-LAT BL Lac objects, but that the LAT-detected
FSRQs are often significantly different from the non-LAT FSRQs. The
differences between the γ-ray loud and quiet FSRQs can be
explained by Doppler boosting; these objects appear to require larger
Doppler factors than those of the BL Lac objects. It is possible that
the γ-ray loud FSRQs are fundamentally different from the
γ-ray quiet FSRQs. Strong polarization at the base of the jet
appears to be a signature for γ-ray loud AGNs.
Description:
We have compared the 11 month 1LAC (Abdo et al., 2010, Cat. J/ApJ/715/429)
to the VIPS (Helmboldt et al. 2007, Cat. J/ApJ/658/203), and from the
intersection compiled a sample of 102 LAT sources at |b|>10°
associated with an AGN with a probability of more than 50% (although
most of the probabilities are greater than 98%). All of these objects
were observed with the VLBA from 1996 to 2006 (although 958 of the
1127 sources were observed during 2006) at 5GHz. Of the LAT objects,
40 are BL Lac objects, 50 are Flat Spectrum Radio Quasars (FSRQs), and
12 are either radio galaxies or unclassified objects.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 102 102 LAT sources in VIPS (VLBA Imaging and Polarimetry
Survey)
--------------------------------------------------------------------------------
See also:
VIII/72 : CLASS survey of radio sources (Myers+, 2003)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/AJ/142/89 : Precise astrometry with VLBA (VIPS) (Petrov+, 2011)
J/ApJ/722/L7 : Fermi/LAT detected MOJAVE AGNs (Pushkarev+, 2010)
J/ApJ/718/587 : The Fermi-AT20G catalog (Mahony+, 2010)
J/ApJ/715/429 : First Fermi-LAT AGN catalog (1LAC) (Abdo+, 2010)
J/ApJ/709/1407 : SED of the Fermi blazars (Li+, 2010)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJS/175/97 : CGRaBS: γ-ray blazar candidates survey (Healey+, 2008)
J/ApJ/671/1355 : EGRET blazars in VIPS (Taylor+, 2007)
J/ApJ/658/203 : VLBA imaging and polarimetry survey at 5GHz (Helmboldt+, 2007)
J/ApJ/626/95 : Gamma-ray blazar candidates (Sowards-Emmerd+, 2005)
J/A+A/379/755 : Radio data of X- and gamma-ray loud blazars (Venturi+, 2001)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [1FGL]
6- 17 A12 --- 1FGL 1FGL name (JHHMM.m+DDMM) from 1LAC
(Cat. J/ApJ/715/429)
19- 29 A11 --- VIPS VIPS name (JHHMMm+DDMM) (Cat. J/ApJ/658/203)
31- 32 I2 h RAh Hour of right ascension (J2000)
34- 35 I2 min RAm Minute of right ascension (J2000)
37- 40 F4.1 s RAs Second of right ascension (J2000)
42 A1 --- DE- [+] Sign of declination (J2000)
43- 44 I2 deg DEd Degree of declination (J2000)
46- 47 I2 arcmin DEm Arcminute of declination (J2000)
49- 54 F6.3 arcsec DEs Arcsecond of declination (J2000)
56- 59 F4.2 --- Prob [0.51/1] Probability of AGN association
61- 64 A4 --- Type Optical classification (BLL=BLLac, FSRQ=Flat
Spectrum Radio Quasar, or RG=Radio Galaxy) from
CGRaBS (Healey et al. 2008, Cat. J/ApJS/175/97)
66- 70 F5.3 --- z [0.028/3.033]? Redshift
72- 75 F4.1 10-5/m2/s F35 The 1-100GeV photon flux from 1LAC (1)
77- 79 F3.1 10-5/m2/s e_F35 ?=0 F35 uncertainty
81- 88 E8.3 K TBc Core brightness temperature
90- 91 I2 deg psi ? Jet opening half-angle ψ (see Taylor
et al., 2007, cat. J/ApJ/671/1355)
93- 95 I3 deg DPA [-84/163]? Difference between the outer and
inner position angles of the jet for sources
with more than two jet components
97-102 F6.1 mJy S8.5 8.5GHz flux density from CLASS (Cat. VIII/72)
--------------------------------------------------------------------------------
Note (1): In units of 10-9photons/cm2/s. An entry of 0.0 in e_F35
indicates that the value of F35 is an upper limit.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Aug-2012