J/A+A/643/A103 Fermi-LATi sources low-energy counterparts (Pena-Herazo+, 2020)
Optical spectroscopic observations of low-energy counterparts of Fermi-LAT
gamma-ray sources.
Pena-Herazo H.A., Amaya-Almazan R.A., Massaro F., de Menezes R.,
Marchesini E.J., Chavushyan V., Paggi A., Landoni M., Masetti N., Ricci F.,
D'Abrusco R., Cheung C.C., La Franca F., Smith H.A., Milisavljevic D.,
Jimenez-Bailon E., Patino-Alvarez V.M., Tosti G.
<Astron. Astrophys. 643, A103 (2020)>
=2020A&A...643A.103P 2020A&A...643A.103P (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; BL Lac objects ; Active gal. nuclei ; Redshifts
Keywords: galaxies: active - BL Lacertae objects: general -
quasars: emission lines - galaxies: luminosity function, mass function
Abstract:
A significant fraction of all gamma-ray sources detected by the Large
Area Telescope aboard the Fermi satellite is still lacking a
low-energy counterpart. In addition, there is still a large population
of gamma-ray sources with associated low-energy counterparts that lack
firm classifications. In the last 10 years we have undertaken an
optical spectroscopic campaign to address the problem of unassociated
or unidentified gamma-ray sources (UGSs), mainly devoted to observing
blazars and blazar candidates because they are the largest population
of gamma-ray sources associated to date.
Here we describe the overall impact of our optical spectroscopic
campaign on sources associated in Fermi-LAT catalogs, coupled with
objects found in the literature. In the literature search we kept
track of efforts by different teams that presented optical spectra of
counterparts or potential counterparts of Fermi-LAT catalog sources.
Our summary includes an analysis of additional 30 newly collected
optical spectra of counterparts or potential counterparts of Fermi-LAT
sources of a previously unknown nature. Methods. New spectra were
acquired at the Blanco 4m and OAN-SPM 2.1m telescopes, and those
available in the Sloan Digital Sky Survey (data release 15) archive.
All new sources with optical spectra analyzed here are classified as
blazars. Thanks to our campaign, altogether we discovered and
classified 394 targets with an additional 123 objects collected from a
literature search. We began our optical spectroscopic campaign between
the release of the second and third Fermi-LAT source catalogs (2FGL
and 3FGL, respectively), classified about 25% of the sources that had
uncertain nature and discovered a blazar-like potential counterpart
for ∼10% of UGSs listed therein. In the 4FGL catalog, about 350
Fermi-LAT sources have been classified to date thanks to our campaign.
The most elusive class of blazars are found to be BL Lacs since the
largest fraction of Fermi-LAT sources targeted in our observations
showed a featureless optical spectrum. The same conclusion applied to
the literature spectra. Finally, we confirm the high reliability of
mid-IR color-based methods to select blazar-like candidate
counterparts of unassociated or unidentified gamma-ray sources.
Description:
Summary of the results achieved thanks to our optical spectroscopic
campaign including all 394 targets (Table B1), and obtained those
obtained from the literature (Table B2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 139 394 Summary of the optical spectroscopic campaign
tableb2.dat 155 123 Summary of literature search
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See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJS/247/33 : The Fermi LAT fourth source catalog (4FGL) (Abdollahi+, 2020)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- Name Fermi designation
20- 23 A4 --- ClassF Fermi classification
25- 52 A28 --- Assoc Associated source
54- 72 A19 --- WISE WISE counterpart (JHHMMSS.ss+DDMMSS.s)
75- 76 I2 h RAh Right Ascension (J2000)
78- 79 I2 min RAm Right Ascension (J2000)
81- 85 F5.2 s RAs Right Ascension (J2000)
87 A1 --- DE- Declination sign (J2000)
88- 89 I2 deg DEd Declination (J2000)
91- 92 I2 arcmin DEm Declination (J2000)
94- 98 F5.2 arcsec DEs Declination (J2000)
100-103 A4 --- ClassO Optical spectral classification
104 A1 --- l_z Limit flag on z
105-111 F7.5 --- z Measured redshift from optical spectra
112 A1 --- u_z [?] Uncertainty flag on z
114-116 A3 --- Ref Reference of the campaign paper (1)
118-135 A18 --- Tel Telescopes used to acquire the spectrum
137-139 A3 --- Lit Reference in literature paper (2)
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Note (1): References of the campaign paper as follows:
a = Cowperthwaite et al., 2013AJ....146..110C 2013AJ....146..110C
b = Alvarez-Crespo et al, 2016AJ....151...32A 2016AJ....151...32A
c = Alvarez-Crespo et al. 2016AJ....151...95A 2016AJ....151...95A
d = Alvarez-Crespo et al. 2016Ap&SS.361..316A 2016Ap&SS.361..316A
e = Landoni et al., 2015AJ....149..163L 2015AJ....149..163L
f = Marchesini et al., 2019Ap&SS.364....5M 2019Ap&SS.364....5M
g = Massaro et al., 2014AJ....148...66M 2014AJ....148...66M
h = Massaro et al., 2015, Cat. J/ApJS/217/2
i = Massaro et al., 2015Ap&SS.357...75M 2015Ap&SS.357...75M
j = Massaro et al., 2016Ap&SS.361..337M 2016Ap&SS.361..337M
k = de Menezes et al., 2019A&A...630A..55D 2019A&A...630A..55D
l = de Menezes et al., 2020ApJS..248...23D 2020ApJS..248...23D
m = Paggi et al., 2014AJ....147..112P 2014AJ....147..112P
n = Pena-Herazo et al., 2017Ap&SS.362..228P 2017Ap&SS.362..228P
o = Pena-Herazo et al., 2019Ap&SS.364...85P 2019Ap&SS.364...85P
p = This work
q = Ricci et al., 2015AJ....149..160R 2015AJ....149..160R
Note (2): References to spectra in the literature as follows:
a = Desai et al., 2019ApJS..241....5D 2019ApJS..241....5D
b = Falco et al., 1998ApJ...494...47F 1998ApJ...494...47F
c = Jones et al., 2009MNRAS.399..683J 2009MNRAS.399..683J, Cat. VII/259
d = Hewitt, & Burbidge, 1980ApJS...43...57H 1980ApJS...43...57H
e = Klindt et al., 2017MNRAS.467.2537K 2017MNRAS.467.2537K
f = La Mura et al., 2017, European Physical Journal D, 71, 95
g = Marchesi et al., 2018AJ....156..212M 2018AJ....156..212M
h = Marchesini et al., 2016A&A...596A..10M 2016A&A...596A..10M
i = Marlow et al., 2000AJ....119.2629M 2000AJ....119.2629M
j = Marti et al., 2004A&A...413..309M 2004A&A...413..309M
k = Masetti et al., 2013A&A...556A.120M 2013A&A...556A.120M
l = Paiano et al., 2017ApJ...851..135P 2017ApJ...851..135P
m = Paiano et al,,. 2017ApJ...844..120P 2017ApJ...844..120P
n = Shaw etal., 2013, Cat. J/ApJ/764/135
o = Titov et al., 2013, Cat. J/AJ/146/10
p = Tsarevsky et al., 2005A&A...438..949T 2005A&A...438..949T
q = Vermeulen & Taylor, 1995AJ....109.1983V 1995AJ....109.1983V
r = Paiano et al., 2019ApJ...871..162P 2019ApJ...871..162P
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 3FGL Fermi 3FGL designation (3FGL JHHMM.m+DDMM)
20- 22 A3 --- Class3 Fermi classification
24- 40 A17 --- 4FGL Fermi 3FGL designation (4FGL JHHMM.m+DDMM)
42- 45 A4 --- Class4 Fermi classification
48- 75 A28 --- Assoc Associated source
77- 95 A19 --- WISE WISE counterpart
97- 98 I2 h RAh Right Ascension (J2000)
100-101 I2 min RAm Right Ascension (J2000)
103-107 F5.2 s RAs Right Ascension (J2000)
109 A1 --- DE- Declination sign (J2000)
110-111 I2 deg DEd Declination (J2000)
113-114 I2 arcmin DEm Declination (J2000)
116-120 F5.2 arcsec DEs Declination (J2000)
122-125 A4 --- Class Optical spectral classification
126 A1 --- l_z Limit flag on z
127-132 F6.4 --- z Measured redshift from optical spectra
133 A1 --- u_z [?] Uncertainty flag on z
135-147 A13 --- Tel Telescopes used to acquire the spectrum
151-155 A5 --- Lit Reference in literature paper (1)
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Note (1): References as follows:
a = Britzen et al., 2007, Cat. J/A+A/476/759
b = Caccianiga et al., 2002, Cat. J/MNRAS/329/877
c = Alvarez-Crespo et al., 2016AJ....151...32A 2016AJ....151...32A
d = Alvarez-Crespo et al., 2016AJ....151...95A 2016AJ....151...95A
e = Desai et al., 2019ApJS..241....5D 2019ApJS..241....5D
f = Hewitt, & Burbidge, 1980ApJS...43...57H 1980ApJS...43...57H
g = Klindt et al., 2017MNRAS.467.2537K 2017MNRAS.467.2537K
h = La Mura et al., 2017, European Physical Journal D, 71, 95
i = Landoni et al., 2018, Cat. J/ApJ/861/130
j = Marchesi et al., 2018AJ....156..212M 2018AJ....156..212M
k = Marchesini et al., 2016A&A...596A..10M 2016A&A...596A..10M
l = Massaro et al., 2015, Cat. J/ApJS/217/2
m = Paggi et al., 2014AJ....147..112P 2014AJ....147..112P
n = Paiano et al., 2017ApJ...851..135P 2017ApJ...851..135P
o = Paiano et al., 2017ApJ...844..120P 2017ApJ...844..120P
p = Paiano et al., 2019ApJ...871..162P 2019ApJ...871..162P
q = Peterson et al., 1976ApJ...207L...5P 1976ApJ...207L...5P
r = Ricci et al., 2015AJ....149..160R 2015AJ....149..160R
s = Shaw et al., 2013, Cat. J/ApJ/764/135
t = Wisotzki et al., 2000, Cat. J/A+A/358/77
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Acknowledgements:
Harold A. Pena-Herazo, harold.penaherazo(at)edu.unito.it
(End) Harold A. Pena-Herazo [Univ. Turin], Patricia Vannier [CDS] 19-Oct-2020