J/ApJ/743/171 The 2LAC catalog (Ackermann+, 2011)
The second catalog of active galactic nuclei detected by the Fermi Large Area
Telescope.
Ackermann M., Ajello M., Allafort A., Antolini E., Atwood W.B.,
Axelsson M., Baldini L., Ballet J., Barbiellini G., Bastieri D.,
Bechtol K., Bellazzini R., Berenji B., Blandford R.D., Bloom E.D.,
Bonamente E., Borgland A.W., Bottacini E., Bouvier A., Bregeon J.,
Brigida M., Bruel P., Buehler R., Burnett T.H., Buson S., Caliandro G.A.,
Cameron R.A., Caraveo P.A., Casandjian J.M., Cavazzuti E., Cecchi C.,
Charles E., Cheung C.C., Chiang J., Ciprini S., Claus R., Cohen-Tanugi J.,
Conrad J., Costamante L., Cutini S., de Angelis A., de Palma F.,
Dermer C.D., Digel S.W., do Couto e Silva E., Drell P.S., Dubois R.,
Escande L., Favuzzi C., Fegan S.J., Ferrara E.C., Finke J., Focke W.B.,
Fortin P., Frailis M., Fukazawa Y., Funk S., Fusco P., Gargano F.,
Gasparrini D., Gehrels N., Germani S., Giebels B., Giglietto N., Giommi P.,
Giordano F., Giroletti M., Glanzman T., Godfrey G., Grenier I.A.,
Grove J.E., Guiriec S., Gustafsson M., Hadasch D., Hayashida M., Hays E.,
Healey S.E., Horan D., Hou X., Hughes R.E., Iafrate G., Johannesson G.,
Johnson A.S., Johnson W.N., Kamae T., Katagiri H., Kataoka J.,
Knodlseder J., Kuss M., Lande J., Larsson S., Latronico L., Longo F.,
Loparco F., Lott B., Lovellette M.N., Lubrano P., Madejski G.M.,
Mazziotta M.N., McConville W., McEnery J.E., Michelson P.F.,
Mitthumsiri W., Mizuno T., Moiseev A.A., Monte C., Monzani M.E.,
Moretti E., Morselli A., Moskalenko I.V., Murgia S., Nakamori T.,
Naumann-Godo M., Nolan P.L., Norris J.P., Nuss E., Ohno M., Ohsugi T.,
Okumura A., Omodei N., Orienti M., Orlando E., Ormes J.F., Ozaki M.,
Paneque D., Parent D., Pesce-Rollins M., Pierbattista M., Piranomonte S.,
Piron F., Pivato G., Porter T.A., Raino S., Rando R., Razzano M.,
Razzaque S., Reimer A., Reimer O., Ritz S., Rochester L.S., Romani R.W.,
Roth M., Sanchez D.A., Sbarra C., Scargle J.D., Schalk T.L., Sgro C.,
Shaw M.S., Siskind E.J., Spandre G., Spinelli P., Strong A.W., Suson D.J.,
Tajima H., Takahashi H., Takahashi T., Tanaka T., Thayer J.G., Thayer J.B.,
Thompson D.J., Tibaldo L., Tinivella M., Torres D.F., Tosti G., Troja E.,
Uchiyama Y., Vandenbroucke J., Vasileiou V., Vianello G., Vitale V.,
Waite A.P., Wallace E., Wang P., Winer B.L., Wood D.L., Wood K.S.,
Zimmer S.
<Astrophys. J., 743, 171 (2011)>
=2011ApJ...743..171A 2011ApJ...743..171A
ADC_Keywords: Gamma rays ; Active gal. nuclei ; Galaxy catalogs ; Redshifts
Keywords: BL Lacertae objects: general - catalogs - galaxies: active -
gamma rays: galaxies
Abstract:
The second catalog of active galactic nuclei (AGNs) detected by the
Fermi Large Area Telescope (LAT) in two years of scientific operation
is presented. The second LAT AGN catalog (2LAC) includes 1017
γ-ray sources located at high Galactic latitudes (|b|>10°)
that are detected with a test statistic (TS) greater than 25 and
associated statistically with AGNs. However, some of these are
affected by analysis issues and some are associated with multiple
AGNs. Consequently, we define a Clean Sample which includes 886 AGNs,
comprising 395 BL Lacertae objects (BL Lac objects), 310 flat-spectrum
radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e.,
with broadband blazar characteristics but with no optical spectral
measurement yet), 8 misaligned AGNs, 4 narrow-line Seyfert 1 (NLS1s),
10 AGNs of other types, and 2 starburst galaxies. Where possible, the
blazars have been further classified based on their spectral energy
distributions (SEDs) as archival radio, optical, and X-ray data
permit. While almost all FSRQs have a synchrotron-peak frequency
<1014Hz, about half of the BL Lac objects have a synchrotron-peak
frequency >1015Hz. The 2LAC represents a significant improvement
relative to the first LAT AGN catalog (1LAC), with 52% more associated
sources. The full characterization of the newly detected sources will
require more broadband data. Various properties, such as γ-ray
fluxes and photon power-law spectral indices, redshifts, γ-ray
luminosities, variability, and archival radio luminosities and their
correlations are presented and discussed for the different blazar
classes. The general trends observed in 1LAC are confirmed.
Description:
This catalog is based on the larger second LAT catalog, 2FGL (Nolan et
al. 2012, Cat. J/ApJS/199/31) and is a follow-up of the first LAT AGN
catalog, 1LAC (Abdo et al. 2010, Cat. J/ApJ/715/429). Here, we report
on the AGNs associated with Fermi/LAT sources detected after the first
24 months of scientific operation; from 2008 August 4 to 2010 August 1.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 135 1017 2LAC sample (high latitude)
table4.dat 135 104 Low Latitude (|b|<10) sources
table6.dat 80 45 1LAC sources missing in 2LAC
table7.dat 96 1017 High latitude sources fluxes
table8.dat 96 104 Low latitude source fluxes
table9.dat 71 40 Properties of the TeV AGNs detected by the Fermi LAT
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See also:
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/A+A/535/A69 : AGN Fermi/LAT γ-ray and 37GHz fluxes (Nieppola+, 2011)
J/ApJ/726/16 : γ-ray loud blazars (Linford+, 2011)
J/ApJ/741/30 : Radio/γ-ray correlation in AGN (Ackermann+, 2011)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/ApJ/742/27 : 15GHz and jet properties of MOJAVE blazars (Lister+, 2011)
J/ApJ/742/66 : Fermi/LAT observations of Swift/BAT active Gal (Teng+, 2011)
J/ApJ/716/30 : SED of Fermi bright blazars (Abdo+, 2010)
J/ApJ/718/587 : The Fermi-AT20G catalog (Mahony+, 2010)
J/ApJ/722/520 : Gamma-ray light curves of Fermi blazars (Abdo+, 2010)
J/ApJ/722/L7 : Fermi/LAT detected MOJAVE AGNs (Pushkarev+, 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/ApJ/706/L7 : The Fermi LAT sky as seen by INTEGRAL/IBIS (Ubertini+, 2009)
J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)
J/ApJ/654/186 : VI photometry of Cepheids in NGC 5128 (Ferrarese+, 2007)
Byte-by-byte Description of file: table[34].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- 2FGL Name of the 2FGL source (JHHMM.m+DDMM)
14 A1 --- Cl? [NY] Source in Clean sample: Y=Yes, N=No
16 A1 --- List [NY] Source in 2FGL list: Y=Yes, N=No
18- 43 A26 --- CName Name of the counterpart
45- 53 F9.5 deg RAdeg Counterpart right ascension (J2000)
55- 63 F9.5 deg DEdeg Counterpart declination (J2000)
65- 69 F5.3 deg Sep [0.001/0.454] 2FGL and its counterpart
angular separation
71- 75 F5.3 deg ePos [0.01/0.387] The 95% error radius
77- 85 A9 --- OType Optical object type (G1)
87- 89 A3 --- SED Type of SED; "-" indicates a NULL value (G2)
91- 97 F7.3 --- z [0/3.215]?=-99.999 Redshift (1)
99-102 F4.2 --- SpI [1.12/3] Spectral Index α
104-107 F4.2 --- e_SpI Error in SpInd
109-114 F6.2 --- pr ?=-99.99 The Bayesian probability of counterpart
116-121 F6.2 --- NSpr ?=-99.99 The logN-logS probability of counterpart
123-128 F6.2 --- RGpr ?=-99.99 Likelihood ratio reliability
for Radio-Gamma association
130-135 F6.2 --- XGpr ?=-99.99 Likelihood ratio reliability
for X-Gamma association
--------------------------------------------------------------------------------
Note (1): A redshift z=0 means that the redshift could not be evaluated even
though an optical spectrum was available (from follow-up campaigns;
see section 4.1), e.g., for BL Lac objects without redshifts, while
no mentioned redshift means that no optical spectrum was available.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- 1FGL 1FGL source name (JHHMM.m+DDMM)
14- 30 A17 --- 1LAC 1LAC counterpart name
32- 40 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
42- 50 F9.5 deg DEdeg Declination in decimal degrees (J2000)
52- 55 A4 --- OType Optical object type (FSRQ, AGN or BLL)
57- 59 A3 --- SED Type of SED (LSP or HSP) (G2)
61- 65 F5.3 --- z ? Redshift
67 A1 --- Note [S] S: the 1FGL source is associated with
exactly one AGN
69 A1 --- Cl? [Y] Source in 1LAC clean sample: Y=Yes
71- 74 F4.2 --- pr Association probability
76- 80 A5 --- Flag 1LAC flag(s) (1)
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Note (1): Flag as follows:
C = Confirmed 1FGL sources;
NC = not confirmed 1FGL sources (see Nolan et al. 2012, Cat. J/ApJS/199/31);
BC = 1FGL sources confirmed by the 11m binned likelihood analysis;
S = the 1FGL source was split/resolved in one or more seeds;
O = overlapping θ99.9 error regions with one or more seeds;
V = variable source visible only in the first 11 months;
UnA = while the γ-ray source is in 2FGL, it is now unassociated due to
the displacement of the γ-ray centroid,
CC = while the γ-ray source is in 2FGL, its counterpart has changed due
to the displacement of the γ-ray centroid.
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Byte-by-byte Description of file: table[78].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- 2FGL Name of 2FGL source
14 A1 --- Cl? [NY] Source in Clean sample: Y=Yes, N=No
16 A1 --- List [NY] Source in 2FGL list: Y=Yes, N=No
18- 43 A26 --- CName Name of the counterpart
45- 50 I6 --- TS Test Statistics: significance
52- 60 F9.2 mJy RFlux [4/138488]?=-99.99 Radio flux
62- 68 F7.2 10-16W/m2 XFlux [0.26/7640]?=-99.99 X-ray flux; in
units of 10-13erg/cm2/s
70- 75 F6.2 mag Vmag1 [8.08/23.15]?=-99.99 USNO V band magnitude
77- 82 F6.2 mag Vmag2 ?=-99.99 SDSS V band magnitude
84- 89 F6.2 --- aox ?=-99.99 Rest frame, multi-frequency
optical/X-ray spectral index (between 5000Å
and 1keV) (1)
91- 96 F6.2 --- aro ?=-99.99 Rest frame, multi-frequency
radio/optical spectral index (between 5GHz and
5000Å) (1)
--------------------------------------------------------------------------------
Note (1): In this work, the broadband spectral indices are calculated from data
in the radio, optical, and X-ray bands. The radio flux measurements
are obtained mainly from the GB6 (Gregory et al. 1996, Cat. VIII/40)
and PMN catalogs. The optical fluxes are taken mainly from the
USNO-B1.0 (Monet et al. 2003, Cat. I/284) and Sloan Digital Sky Survey
(SDSS; Adelman-McCarthy et al. 2008, Cat. II/294) catalogs. The X-ray
fluxes are derived from the ROSAT All Sky Survey (RASS) (Voges et al.
1999, Cat. IX/10), Swift-X-Ray Telescope, White-Giommi-Angelini (White
et al. 2000, Cat. IX/31), XMM (XMM-Newton Survey Science Centre 2010),
and Brera Multi-scale Wavelet (Lazzati et al. 2001misk.conf..501L)
catalogs. See section 4.2 for further details.
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Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Cl? [C] C: in the clean sample of 2LAC (1)
3- 23 A21 --- Name TeV name
24- 26 A3 --- n_Name [*s, ] Individual notes (2)
28- 39 A12 --- 2FGL 2FGL name (JHHMM.m+DDMM)
41- 49 A9 --- Type Object type (G1)
51- 53 A3 --- SED SED type (G2)
55- 62 F8.6 --- z ? Redshift
63- 65 A3 --- f_z [cde, ] Flag on z (2)
68- 69 A2 --- Sp Shape of the best-fit spectrum (PL=power law
or LP=LogParabola)
71 A1 --- 1LAC? [YL] In the 1LAC? (3)
--------------------------------------------------------------------------------
Note (1): 34 AGNs, flagged "C", are in the Clean Sample of 2LAC. The 5 TeV AGNs
and 1 TeV unidentified source that are in 2FGL but not in the 2LAC
clean sample are listed at the end (with no flag).
Note (2): Flag as follows:
c = The redshift assumed for this source is uncertain at z=0.31±0.08 and
is therefore not listed in 2LAC (Anderhub et al. 2009ApJ...704L.129A 2009ApJ...704L.129A).
d = The redshift is not in the 2LAC table because, as a member of the local
group, the redshift does not provide a reliable estimate of its distance.
Ferrarese et al. (2007, Cat. J/ApJ/654/186) used Cepheid variables to
calculate its distance and derived a value of
3.42±0.18(random)±0.25(systematic)Mpc, which we converted to redshift
of z=0.0008, with the tool at this URL:
http://www.astro.ucla.edu/~wright/CosmoCalc.html assuming the
cosmological values quoted in Section 1.
* = Sources for which Fermi LAT data motivated the observations leading to
their discovery at TeV energies.
e = The sources used to make Figure 44.
s = VER J0648+152 is listed as an unidentified source in TeVCat. It is
spatially consistent with the 2LAC AGN, 2FGL J0648+1516.
Note (3): Flag as follows:
Y = source was in the 1LAC Clean Sample;
L = source was in 1FGL but not in 1LAC due to its low Galactic latitude.
All others were not in 1LAC.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Classes for sources with well-established classes in literature
and/or through an optical spectrum with a good evaluation of
emission lines are as follows (see section 4 for further details):
FSRQ = flat-spectrum radio quasar
BL Lac = BL Lac object,
Radio Gal = Radio galaxy,
SSRQ = steep-spectrum radio quasar
Seyfert = Seyfert galaxy,
NLSyI = narrow-line Seyfert 1
starburst = starburst galaxy
AGU = sources without a good optical spectrum or without an optical
spectrum at all
AGN = this class is more generic than "AGU". These sources are not
confirmed blazars nor blazar candidates (such as AGU). Although
they may have had evidence for their flatness in radio emission or
broadband emission, our intensive optical follow-up program did not
provide a clear evidence for optical blazar characteristics.
Note (G2): We estimate the synchrotron-peak frequency νSpeak, using
the broadband indices αro (radio/optical between 5GHz and
5000Å) and αox (optical/X-ray, between 5000Å and 1keV).
The analytic relationship νSpeak=f(αro, αox)
was calibrated with 48 SEDs in Abdo et al. (2010, Cat. J/ApJ/716/30).
We use the estimated value of νSpeak to classify the source as:
LSP = low-synchrotron-peaked blazar (νSpeak<1014Hz)
ISP = intermediate-synchrotron-peaked blazar (1014Hz<νSpeak<1015Hz)
HSP = blazar (νSpeak>1015Hz).
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History:
From electronic version of the journal
References:
Abdo et al. 1LAC catalog. 2010ApJ...715..429A 2010ApJ...715..429A Cat. J/ApJ/715/429
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-May-2013