J/ApJS/222/5 The second Fermi-LAT >50GeV catalog (2FHL) (Ackermann+, 2016)
2FHL: the second catalog of hard Fermi-LAT sources.
Ackermann M., Ajello M., Atwood W.B., Baldini L., Ballet J.,
Barbiellini G., Bastieri D., Becerra Gonzalez J., Bellazzini R.,
Bissaldi E., Blandford R.D., Bloom E.D., Bonino R., Bottacini E.,
Brandt T.J., Bregeon J., Bruel P., Buehler R., Buson S., Caliandro G.A.,
Cameron R.A., Caputo R., Caragiulo M., Caraveo P.A., Cavazzuti E.,
Cecchi C., Charles E., Chekhtman A., Cheung C.C., Chiang J., Chiaro G.,
Ciprini S., Cohen J.M., Cohen-Tanugi J., Cominsky L.R., Conrad J.,
Cuoco A., Cutini S., D'Ammando F., de Angelis A., de Palma F., Desiante R.,
Di Mauro M., Di Venere L., Dominguez A., Drell P.S., Favuzzi C.,
Fegan S.J., Ferrara E.C., Focke W.B., Fortin P., Franckowiak A.,
Fukazawa Y., Funk S., Furniss A.K., Fusco P., Gargano F., Gasparrini D.,
Giglietto N., Giommi P., Giordano F., Giroletti M., Glanzman T.,
Godfrey G., Grenier I.A., Grondin M.-H., Guillemot L., Guiriec S.,
Harding A.K., Hays E., Hewitt J.W., Hill A.B., Horan D., Iafrate G.,
Hartmann D., Jogler T., Johannesson G., Johnson A.S., Kamae T., Kataoka J.,
Knodlseder J., Kuss M., La Mura G., Larsson S., Latronico L.,
Lemoine-Goumard M., Li J., Li L., Longo F., Loparco F., Lott B.,
Lovellette M.N., Lubrano P., Madejski G.M., Maldera S., Manfreda A.,
Mayer M., Mazziotta M.N., Michelson P.F., Mirabal N., Mitthumsiri W.,
Mizuno T., Moiseev A.A., Monzani M.E., Morselli A., Moskalenko I.V.,
Murgia S., Nuss E., Ohsugi T., Omodei N., Orienti M., Orlando E.,
Ormes J.F., Paneque D., Perkins J.S., Pesce-Rollins M., Petrosian V.,
Piron F., Pivato G., Porter T.A., Raino S., Rando R., Razzano M.,
Razzaque S., Reimer A., Reimer O., Reposeur T., Romani R.W.,
Sanchez-Conde M., Parkinson P.M.S., Schmid J., Schulz A., Sgro C.,
Siskind E.J., Spada F., Spandre G., Spinelli P., Suson D.J., Tajima H.,
Takahashi H., Takahashi M., Takahashi T., Thayer J.B., Thompson D.J.,
Tibaldo L., Torres D.F., Tosti G., Troja E., Vianello G., Wood K.S.,
Wood M., Yassine M., Zaharijas G., Zimmer S.
<Astrophys. J. Suppl. Ser., 222, 5 (2016)>
=2016ApJS..222....5A 2016ApJS..222....5A (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; BL Lac objects ; Redshifts
Keywords: catalogs; gamma-rays: general
Abstract:
We present a catalog of sources detected above 50GeV by the
Fermi-Large Area Telescope (LAT) in 80 months of data. The newly
delivered Pass 8 event-level analysis allows the detection and
characterization of sources in the 50GeV-2TeV energy range. In this
energy band, Fermi-LAT has detected 360 sources, which constitute the
second catalog of hard Fermi-LAT sources (2FHL). The improved angular
resolution enables the precise localization of point sources (∼1.7'
radius at 68% C. L.) and the detection and characterization of
spatially extended sources. We find that 86% of the sources can be
associated with counterparts at other wavelengths, of which the
majority (75%) are active galactic nuclei and the rest (11%) are
Galactic sources. Only 25% of the 2FHL sources have been previously
detected by Cherenkov telescopes, implying that the 2FHL provides a
reservoir of candidates to be followed up at very high energies. This
work closes the energy gap between the observations performed at GeV
energies by Fermi-LAT on orbit and the observations performed at
higher energies by Cherenkov telescopes from the ground.
Description:
The Large Area Telescope (LAT) on board the Fermi gamma-ray space
telescope has been surveying the whole sky since 2008 August. In this
paper we use 80 months of Pass 8 data to produce a catalog of sources
detected by the LAT at energies between 50GeV and 2TeV. This
constitutes the second catalog of hard Fermi-LAT sources, named 2FHL,
which allows a thorough study of the properties of the whole sky in
the sub-TeV domain.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
2fhl.dat 373 360 The 2FHL source catalog (see tables 2 and 3)
rois.dat 43 154 Region of interests (ROIs) list
table4.dat 85 20 2FHL extended sources previously detected by
the Fermi-LAT
table5.dat 89 5 New 2FHL extended sources
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Description of file: The original gllpschv08.fit file in FITS format is also
available on the FTP and it includes 3 bintables:
the "2FHL Source Catalog", the "Extended Sources" and the "ROIs"
See also:
VII/274 : The Roma BZCAT - 5th edition (Massaro+, 2015)
VII/189 : Catalog of Pulsars (Taylor+ 1995)
J/A+A/588/A141 : The MWA view of Fermi blazars (Giroletti+, 2016)
J/ApJ/810/14 : Third catalog of LAT-detected AGNs (3LAC) (Ackermann+, 2015)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/A+A/562/A64 : Fermi detection of BL Lac objects (Wu+, 2014)
J/ApJS/209/34 : The first Fermi-LAT >10GeV catalog (1FHL) (Ackermann+, 2013)
J/ApJS/208/17 : 2nd Fermi LAT cat. of gamma-ray pulsars (2PC) (Abdo+, 2013)
J/ApJS/207/16 : BL Lac candidates for TeV observations (Massaro+, 2013)
J/ApJ/764/135 : Spectroscopic redshifts of BL Lac objects (Shaw+, 2013)
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/ApJ/748/49 : Optical spectroscopy of 1LAC broad-line blazars (Shaw+, 2012)
J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)
http://fermi.gsfc.nasa.gov/ssc/ : Fermi Science Support Center home page
http://tevcat.uchicago.edu/ : TeVCat home page
Byte-by-byte Description of file: 2fhl.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [2FHL]
6- 18 A13 --- 2FHL 2FHL name (JHHMM.m+DDMMe) (Source_Name)
20- 27 F8.4 deg RAdeg Right ascension; J2000 (RAJ2000)
29- 36 F8.4 deg DEdeg Declination; J2000 (DEJ2000)
38- 44 F7.3 deg GLON Galactic longitude (GLON)
46- 52 F7.3 deg GLAT Galactic latitude (GLAT)
54- 57 F4.2 deg e_pos [0/0.2] Position uncertainty at 68%
confidence level (Poserr68)
59- 64 F6.1 --- TS [25/5601] Test statistic (TS)
66- 70 F5.2 --- Gam [0.9/15] Observed spectral index
(Spectral_Index) (1)
72- 75 F4.2 --- e_Gam ? 1σ uncertainty on the observed
spectral index (UncSpectralIndex)
77- 81 F5.2 --- SpD11 ? Intrinsic spectral index computed using
the Dominguez et al. (2011MNRAS.410.2556D 2011MNRAS.410.2556D)
EBL model (IntrSpectrlIndex_D11) (1)
83- 86 F4.2 --- e_SpD11 ? 1σ uncertainty on SpD11
(UncIntrSpectralIndexD11)
88- 92 F5.2 --- SpG12 ? Intrinsic spectral index computed using the
Gilmore et al. (2012MNRAS.422.3189G 2012MNRAS.422.3189G) (1)
EBL model (IntrSpectraIndex_G12)
94- 97 F4.2 --- e_SpG12 ? 1σ uncertainty on SpG12
(UncIntrSpectralIndexG12)
99-106 E8.3 ph/cm2/s F50 Integral photon flux from 50GeV to 2TeV
(Flux50)
108-115 E8.3 ph/cm2/s e_F50 1σ uncertainty on F50 (Unc_Flux50)
117-124 E8.3 mW/m2 S50 Energy flux from 50GeV to 2TeV
in erg/cm2/s (Energy_Flux50)
126-133 E8.3 mW/m2 e_S50 1σ uncertainty on S50
(UncEnergyFlux50)
135-142 E8.3 ph/cm2/s F171 Integral photon flux from 50 to 171GeV
(Flux50_171GeV)
144-152 E9.3 ph/cm2/s e_F171 [-0.1/]? 1σ negative uncertainty on F171
(UncFlux50171GeV)
155-162 E8.3 ph/cm2/s E_F171 ? 1σ positive uncertainty on F171
(PositiveUncFlux50_171GeV) (2)
164-168 F5.2 --- TS171 Square root of the Test Statistic between
50 and 171GeV (SqrtTS50171GeV)
170-177 E8.3 ph/cm2/s F585 Integral photon flux from 171 to 585GeV
(Flux171_585GeV)
179-187 E9.3 ph/cm2/s e_F585 [-0.1/]? 1σ negative uncertainty on F585
(UncFlux171585GeV)
190-197 E8.3 ph/cm2/s E_F585 ? 1σ positive uncertainty on F585
(PositiveUncFlux171_585GeV) (2)
199-203 F5.2 --- TS585 Square root of the Test Statistic between
171 and 585GeV (SqrtTS171585GeV)
205-212 E8.3 ph/cm2/s F2000 Integral photon flux from 585GeV to 2TeV
(Flux585_2000GeV)
214-222 E9.3 ph/cm2/s e_F2000 [-0.1/]? 1σ negative uncertainty on F2000
(UncFlux5852000GeV)
225-232 E8.3 ph/cm2/s E_F2000 ? 1σ positive uncertainty on F2000
(PositiveUncFlux585_2000GeV) (2)
234-238 F5.2 --- TS2000 Square root of the Test Statistic between
585GeV and 2TeV (SqrtTS5852000GeV)
240-244 F5.1 --- Npred [3/378] Predicted number of photons from
the source (Npred)
246-251 F6.1 GeV EHEP [52/1997]? Highest photon energy
(HEP_Energy) (3)
253-256 F4.2 --- PHEP [0.85/1]? Probability that the HEP is coming
from the source, ≥0.85 (HEP_Prob) (3)
258-260 I3 --- ROI [1/143] Region of interest number (ROI)
262-286 A25 --- Assoc Name of the most likely associated source
(ASSOC)
288-291 F4.2 --- PBAY [0.8/1]? Probability of association from the
Bayesian method (ASSOCPROBBAY)
293-296 F4.2 --- PLR [0.7/1]? Probability of association from the
likelihood ratio method (ASSOCPROBLR)
298-305 A8 --- Class Class designation for the most likely
association (CLASS) (4)
307-311 F5.3 --- z [0/2.1]? Redshift (when available) of the most
likely associated source (Redshift) (5)
313-320 E8.3 Hz NuPk ? Observed Synchrotron peak frequency
(NuPeak_obs)
322-325 A4 --- --- [3FGL]
327-339 A13 --- 3FGL Name of the most likely associated source
in the 3FGL (3FGLName)
341-344 A4 --- --- [1FHL]
346-358 A13 --- 1FHL Name of the most likely associated source
in the 1FHL (1FHLName)
360-362 A3 --- --- [TeV]
364-373 A10 --- TeVCat Name of the most likely associated source
in the TeVCat (TeVCat_Name)
--------------------------------------------------------------------------------
Note (1): 2FHL J0811.6+0146 is detected with only few photons with energies
around the 50GeV threshold. As such a measurement of its spectral
index is not possible and in the catalog its value has been fixed
to 15.
Note (2): In cases of blank values in e_F171, e_F585 or e_F2000, those values
are the upper errors and the corresponding fluxes are upper limits.
Note (3): Two extended sources, 2FHL J1801.3-2326e and 2FHL J2028.6+4110e,
despite being detected with ∼39 and ∼131 photons, respectively, do
not have single photons that have a probability of belonging to the
source >85%. As such their "HEP_Energy" (EHEP) and "HEP_Prob" (PHEP)
columns are left blank.
Note (4): Class of the most likely associated source (from table 1) as follows:
--------------------------------------------------------------------
Class Description Number
--------------------------------------------------------------------
psr = Pulsar 1
pwn = Pulsar wind nebula 13
snr = Supernova remnant 15
spp = Supernova remnant/Pulsar wind nebula 6
hmb = High-mass binary 2
bin = Binary 1
sfr = Star-forming region 1
bll = BL Lac type of blazar 180
bll-g = BL Lac type of blazar with prominent galaxy emission 13
fsrq = FSRQ type of blazar 10
agn = Non-blazar active galaxy 2
rdg = Radio galaxy 4
rdg/bll = Radio galaxy/BL Lac 2
bcu I = Blazar candidate of uncertain type I 7
bcu II = Blazar candidate of uncertain type II 34
bcu III = Blazar candidate of uncertain type III 19
gal = Normal galaxy (or part) 1
galclu = Galaxy cluster 1
Total associated 312
unk = Unassociated 48
Total in 2FHL 360
--------------------------------------------------------------------
The designation "spp" indicates potential association with SNR or PWN.
The "bcu I," "bcu II," and "bcu III" classes are derived from 3LAC and
describe the increasing lack of multiwavelength information to classify
the source as a blazar (see Ackermann et al. 2015, J/ApJ/810/14 for
more details). The designation "bll-g" is adapted from the BZCAT
(Massaro et al. 2015, VII/274) and indicates a blazar whose SED has
a significant contribution from the host galaxy.
Note (5): Redshifts were taken from from Shaw et al. (2012, J/ApJ/748/49;
2013, J/ApJ/764/135), Masetti et al. (2013A&A...559A..58M 2013A&A...559A..58M) and the
NED and SIMBAD databases.
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Byte-by-byte Description of file: rois.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ROI [1/154] Running sequence number of the
Region of Interest (ROI)
5- 12 F8.4 deg RAdeg Right ascension in decimal degrees (J2000)
14- 21 F8.4 deg DEdeg Declination in decimal degrees (J2000)
23- 29 F7.3 deg GLON Galactic longitude
31- 37 F7.3 deg GLAT Galactic latitude
39- 43 F5.2 deg Rad [5/25] Radius
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- 2FHL 2FHL name (JHHMM.m+DDMMe) (1)
15- 21 F7.3 deg GLON [6.5/347.4] Galactic longitude
23- 29 F7.3 deg GLAT [-32.9/3.1] Galactic latitude
31- 36 F6.2 --- TS [28/438] Test Statistic
38- 52 A15 --- Assoc Name of the most likely associated source
54- 56 A3 --- Class Class designation for the most likely
association
58- 68 A11 --- Mod Spatial model
70- 85 A16 deg Ext Extension(s) (2)
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Note (1): List of the 20 extended sources in the 2FHL that were previously
detected as extended by the Fermi-LAT. All these sources are in 3FGL
except W41, which is studied by
Abramowski et al. (2015A&A...574A..27H 2015A&A...574A..27H).
Note (2): The extension of the disk templates is given by the radius, the
extension of the two-dimensional (2D) Gaussian templates is given by
the 1σ radius, and the elliptical templates are given by the
semimajor axis, semiminor axis, and position angle (east of north).
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- 2FHL 2FHL name (JHHMM.m+DDMMe) (1)
15- 21 F7.3 deg GLON Galactic longitude
23- 28 F6.3 deg GLAT Galactic latitude
30- 34 F5.1 --- TS [75.6/109.3] Test Statistic
36- 39 F4.1 --- TSex [29.9/83.4] Extended Test Statistic TSext
41- 44 F4.1 --- TS2p [12.9/26.2] Second point source TS (TS2pts)
46- 50 F5.2 --- F50 [7.2/17.6] Integral photon flux from
50GeV to 2TeV
52- 55 F4.2 --- e_F50 [1.7/2.8] 1σ uncertainty on F50
57- 60 F4.2 --- Gamma [1.5/2.2] Observed spectral index
62- 65 F4.2 --- e_Gamma [0.1/0.3] 1σ uncertainty on Gamma
67- 80 A14 --- Assoc Name of the most likely associated source
82- 84 A3 --- Class Class designation for the most likely
association
86- 89 F4.2 deg Rad [0.2/1.3] Radius
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Note (1): List of the 5 new extended sources in the 2FHL. All these sources are
characterized by an uniform disk template whose radius is given in
the last column.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Feb-2016