J/ApJ/838/139 Radio follow-up on 3FGL unassociated sources (Schinzel+, 2017)
Radio follow-up on all unassociated gamma-ray sources from the third
Fermi Large Area Telescope source catalog.
Schinzel F.K., Petrov L., Taylor G.B., Edwards P.G.
<Astrophys. J., 838, 139-139 (2017)>
=2017ApJ...838..139S 2017ApJ...838..139S (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; Radio continuum ; Cross identifications
Keywords: catalogs; galaxies: active; gamma rays: general
radio continuum: general; surveys
Abstract:
The third Fermi Large Area Telescope γ-ray source catalog (3FGL)
contains over 1000 objects for which there is no known counterpart at
other wavelengths. The physical origin of the γ-ray emission
from those objects is unknown. Such objects are commonly referred to
as unassociated and mostly do not exhibit significant γ-ray flux
variability. We performed a survey of all unassociated γ-ray
sources found in 3FGL using the Australia Telescope Compact Array and
Very Large Array in the range 4.0-10.0 GHz. We found 2097 radio
candidates for association with γ-ray sources. The follow-up
with very long baseline interferometry for a subset of those
candidates yielded 142 new associations with active galactic nuclei
that are γ-ray sources, provided alternative associations for
seven objects, and improved positions for another 144 known
associations to the milliarcsecond level of accuracy. In addition, for
245 unassociated γ-ray sources we did not find a single compact
radio source above 2 mJy within 3σ of their γ-ray
localization. A significant fraction of these empty fields, 39%, are
located away from the Galactic plane. We also found 36 extended radio
sources that are candidates for association with a corresponding
γ-ray object, 19 of which are most likely supernova remnants or
H II regions, whereas 17 could be radio galaxies.
Description:
The 3FGL catalog covers the entire sky, thus we performed follow-up
observations at two radio interferometric arrays: The Australia
Telescope Compact Array (ATCA) in the Southern Hemisphere for
observing sources with declinations in the range [-90,+10] and the
Jansky Very Large Array (VLA) in the Northern Hemisphere for observing
sources with declinations [0,+90].
ATCA observations were made in three campaigns: A3 started on 2014
April 7 and lasted for 30hr, A4 started on 2014 September 23 and
lasted for 66hr, and A5 started on 2015 April 4 and lasted for 8hr.
Observations in all three campaigns were recorded simultaneously in
two bands centered at 5.5 and 9.0GHz.
A total of 322 unassociated 3FGL fields with decl. above 0° were
selected for observations with NRAO's Jansky VLA in this campaign
(V2). Additionally, we observed the location of 2FGL J0423.4+5612, for
which no data were recorded in our previous VLA survey. We reanalyzed
our previous campaign V1 (Schinzel+ 2015, J/ApJS/217/4). The
observations were conducted using the C-Band receiver covering the
frequency range 4-8GHz. The observing time of 10hr was split into
five segments. The first four segments were observed between 2015
March 16 and 21 under time approved through the NASA Fermi Guest
Investigator program; an additional hour to complete the program was
observed on 2015 April 16.
See section 2 for further details.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 350 2097 The catalog of 2097 objects detected at 5, 7 or
9GHz subbands
table3.dat 136 291 Associations of 3FGL objects with compact radio
sources
table5.dat 57 158 The list of 158 extended sources found around
3FGL unassociated γ-ray objects
table6.dat 49 245 The list of 245 3FGL unassociated objects that
have no radio source brighter 2mJy within
3-σ localization error ellipse
outside.dat 95 1842 Objects outside the 3-σ Fermi localization
error ellipse (datafile_online.txt)
--------------------------------------------------------------------------------
See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/78 : Sydney University Molonglo Sky Survey (SUMSS) (Mauch+ 2006)
VIII/82 : 2nd Epoch Molonglo Galactic Plane Survey (MGPS-2) (Murphy+, 2007)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999)
J/A+A/489/849 : Revised catalog of EGRET gamma-ray sources (Casandjian+, 2008)
J/AJ/136/580 : Sixth VLBA calibrator survey: VCS6 (Petrov+, 2008)
J/ApJ/743/171 : The 2LAC catalog (Ackermann+, 2011)
J/MNRAS/414/2528 : LBA Calibrator Survey (LCS1) (Petrov+, 2011)
J/ApJ/753/83 : Associations to 1FGL sources (Ackermann+, 2012)
J/ApJS/208/17 : 2nd Fermi LAT cat. of gamma-ray pulsars (2PC) (Abdo+, 2013)
J/AJ/146/5 : Optically Bright extragalactic Radio Sources II (Petrov, 2013)
J/MNRAS/432/1294 : Fermi unassociated sources ATCA observations (Petrov+, 2013)
J/MNRAS/435/400 : ATLASGAL compact HII regions (Urquhart+, 2013)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJS/217/4 : 2FGL sources observed between 5-9GHz (Schinzel+, 2015)
J/A+A/598/A78 : The GMRT 150MHz all-sky radio survey (TGSS) (Intema+, 2017)
http://astrogeo.org/rfc/ : The Radio Fundamental Catalog (RFC) home page
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [FRC]
5- 14 A10 --- Name IAU name of the radio source (JHHMM+DDMM; FRC)
17- 18 I2 h RAh Hour of Right Ascension (J2000)
20- 21 I2 min RAm Minute of Right Ascension (J2000)
23- 27 F5.2 s RAs Second of Right Ascension (J2000)
29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 40 F5.2 arcsec DEs Arcsecond of Declination (J2000)
43- 47 F5.2 arcsec e_RAs [0.3/8.1] Uncertainty in RAs;
without cos(DE) factor
49- 53 F5.2 arcsec e_DEs [0.3/4.1] Uncertainty in DEs
55- 55 A1 --- l_F5GHz Flag for flux density at 5GHz (G1)
56- 61 F6.1 mJy F5GHz [0.7/7385]? Flux density at 5GHz
63- 66 F4.1 mJy e_F5GHz [0.1/23]? Uncertainty in flux density at 5GHz
68- 68 A1 --- l_F9GHz Flag for flux density at 9GHz (G1)
69- 74 F6.1 mJy F9GHz [1/5949]? Flux density at 9GHz
76- 79 F4.1 mJy e_F9GHz [0.1/4]? Uncertainty in flux density at 9GHz
82- 86 F5.2 --- Spind [-4.6/5]? Spectral index between 5 and 9GHz
88- 91 F4.2 --- e_Spind [0/2]? Uncertainty in spectral index
94- 95 A2 --- CID Campaign ID (see the "Description" section
above)
97-100 A4 --- --- [3FGL]
102-114 A13 --- 3FGL 3FGL name of the gamma-ray source
(JHHMM.m+DDMMa)
116-120 F5.2 arcmin Sep [0.06/15] Distance between gamma-ray and
radio source
122-125 F4.2 --- NSep [0.05/3] Distance between gamma-ray and
radio source normalized by its uncertainty
128-130 A3 --- --- [RFC]
132-141 A10 --- RFC ID of the matching object in RFC catalogue
(JHHMM+DDMM) (G2)
143-148 F6.1 mJy F8GHz [3/1329]? Correlated flux density at 8GHz of
matching source from the RFC catalogue
150-156 F7.1 --- LR [0/41460]? The likelihood ratio of
radio-gamma association
159-163 A5 --- --- [SUMSS]
165-178 A14 --- SUMSS ID of the matching object in SUMSS or
MGPS-2 catalogue (JHHMMSS+DDMMSS)
180-186 F7.1 mJy F0.84GHz [6/1897]? Flux density of matching source
from SUMSS or MGPS-2 catalogues at 0.84GHz
188-191 A4 --- --- [NVSS]
193-205 A13 --- NVSS ID of the matching object in NVSS catalogue
(HHMMSS+DDMMSS; J2000)
207-214 F8.1 mJy F1.4GHz [2/161188]? Flux density of matching source
from NVSS catalogue at 1.4GHz
217-220 A4 --- --- [TGGS]
222-237 A16 --- TGSSADR ID of the matching source from TGSS catalogue
(JHHMMSS.s+DDMMSS)
240-246 F7.1 mJy F0.15GHz [21/63865]? Integral flux density of matching
source from TGSS catalogue at 0.15GHz
249-252 A4 --- --- [WISE]
254-272 A19 --- WISEA ID of a matching object in WISE catalogue
(JHHMMSS.ss+DDMMSS.s)
274-278 F5.2 mag W1mag [-0.3/18.4]? Magnitude of matching source
from ALLWISE catalogue at 3.4 micron
281-284 A4 --- --- [GAIA]
285-304 I20 --- GAIA ? ID of a matching object in Gaia DR1 catalog
306-310 F5.2 mag Gmag [7.3/21.2]? Magnitude of matching source
from Gaia catalogue at G filter
313-314 I2 h RAOh ? Hour of Right Ascension of
matching Gaia source (J2000)
316-317 I2 min RAOm ? Minute of Right Ascension (J2000)
319-326 F8.5 s RAOs ? Second of Right Ascension (J2000)
328-328 A1 --- DEO- Sign of the Declination of
matching Gaia source (J2000)
329-330 I2 deg DEOd ? Degree of Declination of
matching Gaia source (J2000)
332-333 I2 arcmin DEOm ? Arcminute of Declination (J2000)
335-341 F7.4 arcsec DEOs ? Arcsecond of Declination (J2000)
344-350 F7.5 --- PFA [0/0.005]? Probability of false association
with Gaia
--------------------------------------------------------------------------------
Byte-by-byte Description of file (#): table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [3FGL]
6- 18 A13 --- 3FGL 3FGL name of the gamma-ray source (JHHMM.m+DDMM)
20- 22 A3 --- --- [RFC]
24- 33 A10 --- RFC IAU name of the radio source (JHHMM+DDMM) (G2)
36- 37 I2 h RAh Hour of Right Ascension (J2000)
39- 40 I2 min RAm Minute of Right Ascension (J2000)
42- 50 F9.6 s RAs Second of Right Ascension (J2000)
52 A1 --- DE- Sign of the Declination (J2000)
53- 54 I2 deg DEd Degree of Declination (J2000)
56- 57 I2 arcmin DEm Arcminute of Declination (J2000)
59- 66 F8.5 arcsec DEs Arcsecond of Declination (J2000)
69- 74 F6.2 mas eRA [0.1/757] Uncertainty in right ascension of the
VLBI position without cos(DE) factor
76- 81 F6.2 mas eDE [0.1/999.99] Uncertainty in declination of the
VLBI position
83- 88 F6.3 --- Cor [-1/1] Correlation between right ascension and
declination VLBI position estimates
90- 94 F5.2 arcmin Sep [0.06/12.1] Distance between gamma-ray and
radio source
96- 99 F4.2 --- NSep [0.06/3] Distance between gamma-ray and
radio source normalized by its uncertainty
101-106 F6.1 mJy S8GHz [6/1329] Total VLBI flux density at 8GHz
108-114 F7.1 --- LR [8/41460] The likelihood ratio of
radio-gamma association
117-136 A20 --- Assoc Association reported in the 3FGL source catalogue
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- 3FGL 3FGL name of the gamma-ray source (JHHMM.m+DDMMa)
16- 17 I2 h RAh ? Hour of Right Ascension (J2000)
19- 20 I2 min RAm ? Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs ? Second of Right Ascension (J2000)
29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd ? Degree of Declination (J2000)
33- 34 I2 arcmin DEm ? Arcminute of Declination (J2000)
36- 41 F6.3 arcsec DEs ? Arcsecond of Declination (J2000)
44- 48 F5.2 arcmin Sep [0.3/34]? Distance between gamma-ray and radio
positions
51- 54 F4.1 --- NSep [0.1/28]? Distance between gamma-ray and radio
source normalized by its uncertainty
57 I1 --- C Source class (1)
--------------------------------------------------------------------------------
Note (1): Source class as follows:
1 = large angular scale object;
2 = double or jetted source.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [3FGL]
6- 18 A13 --- 3FGL 3FGL name of the gamma-ray source (JHHMM.m+DDMMa)
21- 36 A16 --- TGSSADR TGSS ADR1 name near the 3FGL position
(JHHMMSS.s+DDMMSS)
39- 42 F4.1 arcmin Sep [0.8/16]? Distance between gamma-ray and radio
positions
45- 49 F5.1 --- NSep [13/177]? Distance between gamma-ray and radio
source normalized by its uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: outside.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- --- [FRC]
5- 14 A10 --- Name IAU name of the radio source (JHHMM+DDMM; FRC)
17- 18 I2 h RAh Hour of Right Ascension (J2000)
20- 21 I2 min RAm Minute of Right Ascension (J2000)
23- 27 F5.2 s RAs Second of Right Ascension (J2000)
29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 40 F5.2 arcsec DEs Arcsecond of Declination (J2000)
43- 47 F5.2 arcsec e_RAs [0.3/8] Uncertainty in RAs;
without cos(DE) factor
49- 53 F5.2 arcsec e_DEs [0.3/6] Uncertainty in DEs
55- 55 A1 --- l_F5GHz Flag for flux density at 5GHz (G1)
56- 61 F6.1 mJy F5GHz [0.8/6276]? Flux density at 5GHz
63- 66 F4.1 mJy e_F5GHz [0.1/100]? Uncertainty in flux density at 5GHz
68- 68 A1 --- l_F9GHz Flag for flux density at 9GHz (G1)
69- 74 F6.1 mJy F9GHz [1/9035]? Flux density at 9GHz
76- 79 F4.1 mJy e_F9GHz [0.1/74]? Uncertainty in flux density at 9GHz
82- 86 F5.2 --- Spind [-3.5/5]? Spectral index between 5 and 9GHz
88- 91 F4.2 --- e_Spind [0/1]? Uncertainty in spectral index
94- 95 A2 --- CID Campaign ID (see the "Description" section
above)
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Global notes:
Note (G1): If flag for flux density is < then the low limit of flux density is
presented; If flag for flux density is blank then the estimate of
limit of flux density is presented.
Note (G2): Name of a counterpart in the VLBI catalog Radio Fundamental Catalog
(RFC; available at http://astrogeo.org/rfc)
(L. Petrov & Y. Y. Kovalev 2017, in preparation) within 20".
--------------------------------------------------------------------------------
Acknowledgments:
Leonid Petrov, Leonid.Petrov(at)lpetrov.net
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Nov-2017