J/ApJ/771/57 Fermi-LAT flaring gamma-ray sources from FAVA (Ackermann+, 2013)
The Fermi All-sky Variability Analysis: a list of flaring gamma-ray sources and
the search for transients in our galaxy.
Ackermann M., Ajello M., Albert A., Allafort A., Antolini E., Baldini L.,
Ballet J., Barbiellini G., Bastieri D., Bechtol K., Bellazzini R.,
Blandford R.D., Bloom E.D., Bonamente E., Bottacini E., Bouvier A.,
Brandt T.J., Bregeon J., Brigida M., Bruel P., Buehler R., Buson S.,
Caliandro G.A., Cameron R.A., Caraveo P.A., Cavazzuti E., Cecchi C.,
Charles E., Chekhtman A., Cheung C.C., Chiang J., Chiaro G., Ciprini S.,
Claus R., Cohen-Tanugi J., Conrad J., Cutini S., Dalton M., D'Ammando F.,
de Angelis A., de Palma F., Dermer C.D., Di Venere L., Drell P.S.,
Drlica-Wagner A., Favuzzi C., Fegan S.J., Ferrara E.C., Focke W.B.,
Franckowiak A., Fukazawa Y., Funk S., Fusco P., Gargano F., Gasparrini D.,
Germani S., Giglietto N., Giordano F., Giroletti M., Glanzman T.,
Godfrey G., Grenier I.A., Grondin M.-H., Grove J.E., Guiriec S.,
Hadasch D., Hanabata Y., Harding A.K., Hayashida M., Hays E., Hewitt J.,
Hill A.B., Horan D., Hou X., Hughes R.E., Inoue Y., Jackson M.S.,
Jogler T., Johannesson G., Johnson W.N., Kamae T., Kataoka J., Kawano T.,
Knodlseder J., Kuss M., Lande J., Larsson S., Latronico L.,
Lemoine-Goumard M., Longo F., Loparco F., Lott B., Lovellette M.N.,
Lubrano P., Mayer M., Mazziotta M.N., McEnery J.E., Michelson P.F.,
Mitthumsiri W., Mizuno T., Monte C., Monzani M.E., Morselli A.,
Moskalenko I.V., Murgia S., Nemmen R., Nuss E., Ohsugi T., Okumura A.,
Omodei N., Orienti M., Orlando E., Ormes J.F., Paneque D., Panetta J.H.,
Perkins J.S., Pesce-Rollins M., Piron F., Pivato G., Porter T.A., Raino S.,
Rando R., Razzano M., Reimer A., Reimer O., Romoli C., Roth M.,
Sanchez-Conde M., Scargle J.D., Schulz A., Sgro C., Siskind E.J.,
Spandre G., Spinelli P., Suson D.J., Takahashi H., Takeuchi Y.,
Thayer J.G., Thayer J.B., Thompson D.J., Tibaldo L., Tinivella M.,
Torres D.F., Tosti G., Troja E., Tronconi V., Usher T.L., Vandenbroucke J.,
Vasileiou V., Vianello G., Vitale V., Winer B.L., Wood K.S., Wood M.,
Yang Z.
<Astrophys. J., 771, 57 (2013)>
=2013ApJ...771...57A 2013ApJ...771...57A
ADC_Keywords: Gamma rays ; Active gal. nuclei ; Cross identifications
Mission_Name: Fermi
Keywords: binaries: general; BL Lacertae objects: general; catalogs
galaxies: active; stars: flare; surveys
Abstract:
In this paper, we present the Fermi All-sky Variability Analysis
(FAVA), a tool to systematically study the variability of the
gamma-ray sky measured by the Large Area Telescope on board the Fermi
Gamma-ray Space Telescope. For each direction on the sky, FAVA
compares the number of gamma-rays observed in a given time window to
the number of gamma-rays expected for the average emission detected
from that direction. This method is used in weekly time intervals to
derive a list of 215 flaring gamma-ray sources. We proceed to discuss
the 27 sources found at Galactic latitudes smaller than 10° and
show that, despite their low latitudes, most of them are likely of
extragalactic origin.
Description:
We applied FAVA (Fermi All-sky Variability Analysis) to the first 47
months of Fermi/LAT observations (2008 August 4 to 2012 July 16 UTC),
in weekly time intervals. The total number of weeks is 206. We
considered two ranges of gamma-ray energy, E>100MeV and E>800MeV, to
increase the sensitivity for spectrally soft and hard flares,
respectively. We generate measured and expected count maps with a
resolution of 0.25deg2 per pixel.
We found LAT counterparts for 192 of the 215 FAVA sources. Most of the
associated sources, 177, are AGNs.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 85 215 List of FAVA sources
lcs/* . 216 Plot of weekly flux variations for all 1FAV
sources (PDF format)
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See also:
J/ApJS/199/31 : Fermi LAT second source catalog (2FGL) (Nolan+, 2012)
J/ApJ/756/33 : X-ray sources near 2 γ-ray sources (Cheung+, 2012)
J/A+A/548/A106 : PMN J0948+0022 radio-to-gamma-ray monitoring (Foschini+, 2012)
J/ApJ/743/171 : The 2LAC catalog (Ackermann+, 2011)
J/ApJ/742/66 : New Fermi/LAT extragalactic sources (Teng+, 2011)
J/ApJ/741/30 : Radio/γ-ray correlation in AGN (Ackermann+, 2011)
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/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/A+A/370/468 : Variability of gamma-ray sources (Torres+, 2001)
J/ApJS/120/409 : The SMM Atlas of Gamma-Ray flares (Vestrand+, 1999)
http://www.asdc.asi.it/feratel/ : List of sources in Fermi LAT ATels
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- 1FAV FAVA identifier (JHHMM+DD)
10- 14 F5.1 deg GLON Galactic longitude
16- 20 F5.1 deg GLAT Galactic latitude
22- 24 F3.1 deg R68 [0.1/0.8] Statistical position error at
68% confidence (1)
26- 28 I3 --- Nf [1/168] Total number of detected flares
30- 32 I3 --- Nhe [0/137] Number of flares with detections at
high energy
34- 36 I3 --- Nneg [0/123] Number of flares corresponding to
negative flux variations
38- 40 F3.1 deg Rs [0.3/1.8] Distance between FAV and counterpart
source (2)
42- 58 A17 --- LAT Associated Fermi-LAT identifier (192 likely
counterpart) (2)
60- 63 I4 --- ATel ? ATel publication number
65- 85 A21 --- Assoc Associated object at longer wavelength
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Note (1): The systematic error on the source position is 0.1°.
Note (2): We looked for associations of FAVA sources with previously known
variable LAT sources. We searched for counterparts within radius Rs,
which is derived as the 99% statistical error plus the systematic
error. Rs was deliberately chosen to be large, to include all possible
counterparts. In cases for which more than one counterpart is found
within Rs, we consider the closest one. We note that the associations
were made purely on the basis of positional coincidence. We therefore
caution that the associated sources should be considered as likely
counterparts only. For a more confident source association, temporal
and spectral information need to be considered. See section 3.
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History:
From electronic version of the journal for the table.
lcs files downloaded at https://www-glast.stanford.edu/pub_data/585/
(End) Emmanuelle Perret [CDS] 16-Jan-2015