THE FERMI ALL-SKY VARIABILITY ANALYSIS: A LIST OF FLARING GAMMA-RAY SOURCES AND THE SEARCH FOR TRANSIENTS IN OUR GALAXY

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.

D. Thompson | J. Chiang | J. Grove | J. Scargle | M. Razzano | R. Blandford | K. Bechtol | A. Drlica-Wagner | M. Ackermann | J. Conrad | A. Franckowiak | J. Vandenbroucke | A. Morselli | Z. Yang | V. Vitale | T. Ohsugi | B. Lott | E. Troja | P. Drell | G. Barbiellini | A. Angelis | B. Winer | R. Hughes | J. Mcenery | N. Giglietto | P. Spinelli | R. Bellazzini | J. Ormes | C. Cecchi | K. Wood | M. Sanchez-conde | T. Kamae | P. Bruel | M. Roth | D. Paneque | S. Ciprini | D. Gasparrini | N. Omodei | F. D’Ammando | Y. Fukazawa | T. Mizuno | G. Tosti | A. Albert | F. Longo | J. Ballet | E. Ferrara | E. Bloom | G. Godfrey | E. Bonamente | R. Nemmen | L. Latronico | G. Spandre | A. Chekhtman | P. Lubrano | T. Brandt | J. Panetta | R. Claus | T. Glanzman | S. Fegan | D. Horan | J. Kataoka | I. Grenier | P. Caraveo | A. Bouvier | J. Perkins | S. Murgia | J. Cohen-Tanugi | J. Thayer | J. Thayer | F. Palma | C. Dermer | Y. Inoue | Hiromitsu Takahashi | S. Funk | R. Rando | M. Ajello | A. Allafort | D. Bastieri | R. Buehler | S. Buson | R. Cameron | W. Focke | D. Hadasch | T. Jogler | J. Knödlseder | J. Lande | A. Okumura | A. Reimer | O. Reimer | A. Schulz | L. Tibaldo | D. Torres | T. Usher | A. Hill | A. Harding | L. Baldini | J. Bregeon | M. Jackson | M. Kuss | S. Larsson | C. Sgro’ | E. Cavazzuti | T. Kawano | S. Guiriec | S. Cutini | M. Brigida | G. Caliandro | C. Favuzzi | F. Gargano | S. Germani | F. Giordano | F. Loparco | M. Mazziotta | C. Monte | M. Pesce-Rollins | S. Rainó | F. Piron | P. Michelson | M. Lemoine-Goumard | C. Cheung | E. Bottacini | E. Charles | G. Chiaro | L. Venere | P. Fusco | M. Giroletti | E. Hays | J. Hewitt | G. Jóhannesson | M. Lovellette | W. Mitthumsiri | I. Moskalenko | E. Nuss | M. Orienti | E. Orlando | E. Siskind | D. Suson | G. Vianello | M. Grondin | C. Romoli | M. Dalton | V. Vasileiou | X. Hou | M. Mayer | M. Monzani | G. Pivato | M. Tinivella | M. Wood | W. Johnson | T. Porter | E. Antolini | Y. Hanabata | M. Hayashida | Y. Takeuchi | C. C. Cheung | V. Tronconi | A. Reimer | J. Conrad | A. Schulz | M. Sánchez-Conde | H. Takahashi | M. Roth | W. Johnson | E. Charles | S. Rainò | D. Thompson | R. Hughes

[1]  Vlasios Vasileiou,et al.  THE FERMI LARGE AREA TELESCOPE ON ORBIT: EVENT CLASSIFICATION, INSTRUMENT RESPONSE FUNCTIONS, AND CALIBRATION , 2012 .

[2]  D. Thompson,et al.  Radio-to-γ-ray monitoring of the narrow-line Seyfert 1 galaxy PMN J0948+0022 from 2008 to 2011 , , 2012, 1209.5867.

[3]  N. Gehrels,et al.  Chandra X-Ray Observations of the Two Brightest Unidentified High Galactic Latitude Fermi-LAT Gamma-Ray Sources , 2012, 1207.1129.

[4]  A. Lutovinov,et al.  Search for variable gamma-ray emission from the Galactic plane in the Fermi data , 2012, 1207.1991.

[5]  J. Chiang,et al.  FERMI-LAT OBSERVATIONS OF THE DIFFUSE γ-RAY EMISSION: IMPLICATIONS FOR COSMIC RAYS AND THE INTERSTELLAR MEDIUM , 2012 .

[6]  H. Takahashi,et al.  Gamma-ray follow-up studies on η Carinae , 2012, 1203.4939.

[7]  T. Tanaka,et al.  LONG-TERM MONITORING OF THE HIGH-ENERGY γ-RAY EMISSION FROM LS I +61°303 AND LS 5039 , 2012, 1202.1866.

[8]  D. Thompson,et al.  Periodic Emission from the Gamma-Ray Binary 1FGL J1018.6–5856 , 2012, Science.

[9]  J. Chiang,et al.  GAMMA-RAY ACTIVITY IN THE CRAB NEBULA: THE EXCEPTIONAL FLARE OF 2011 APRIL , 2011, 1112.1979.

[10]  Vlasios Vasileiou,et al.  FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG , 2011 .

[11]  M. Frailis,et al.  THE RADIO/GAMMA-RAY CONNECTION IN ACTIVE GALACTIC NUCLEI IN THE ERA OF THE FERMI LARGE AREA TELESCOPE , 2011, 1108.0501.

[12]  Gino Tosti,et al.  FERMI LARGE AREA TELESCOPE OBSERVATIONS OF TWO GAMMA-RAY EMISSION COMPONENTS FROM THE QUIESCENT SUN , 2011 .

[13]  J. Chiang,et al.  DISCOVERY OF HIGH-ENERGY GAMMA-RAY EMISSION FROM THE BINARY SYSTEM PSR B1259−63/LS 2883 AROUND PERIASTRON WITH FERMI , 2011, 1103.4108.

[14]  F. Longo,et al.  Gamma-Ray Flares from the Crab Nebula , 2010, Science.

[15]  M. Trifoglio,et al.  Discovery of Powerful Gamma-Ray Flares from the Crab Nebula , 2011, Science.

[16]  D. Thompson,et al.  FERMI LARGE AREA TELESCOPE OBSERVATION OF A GAMMA-RAY SOURCE AT THE POSITION OF ETA CARINAE , 2010, 1008.3235.

[17]  Jean-Luc Starck,et al.  THE FERMI-LAT HIGH-LATITUDE SURVEY: SOURCE COUNT DISTRIBUTIONS AND THE ORIGIN OF THE EXTRAGALACTIC DIFFUSE BACKGROUND , 2010, 1003.0895.

[18]  T Glanzman,et al.  Gamma-ray emission concurrent with the nova in the symbiotic binary V407 Cygni. , 2010, Science.

[19]  E. Striani,et al.  FERMI LARGE AREA TELESCOPE FIRST SOURCE CATALOG , 2010 .

[20]  D. Thompson,et al.  γ-RAY SPECTRAL EVOLUTION OF NGC 1275 OBSERVED WITH FERMI LARGE AREA TELESCOPE , 2010, 1004.2352.

[21]  K. Bechtol,et al.  DISCOVERY OF A GeV BLAZAR SHINING THROUGH THE GALACTIC PLANE , 2010, 1004.1413.

[22]  L. A. Antonelli,et al.  EPISODIC TRANSIENT GAMMA-RAY EMISSION FROM THE MICROQUASAR CYGNUS X-1 , 2010, 1002.4967.

[23]  D. Thompson,et al.  Modulated High-Energy Gamma-Ray Emission from the Microquasar Cygnus X-3 , 2009, Science.

[24]  Yasuyuki T. Tanaka,et al.  FERMI/LAT OBSERVATIONS OF LS 5039 , 2009 .

[25]  A. R. Bazer-Bachi,et al.  Simultaneous multiwavelength observations of the second exceptional gamma-ray flare of PKS 2155-304 in July 2006 , 2009, 0906.2002.

[26]  G. Piano,et al.  DETECTION OF GAMMA-RAY EMISSION FROM THE ETA-CARINAE REGION , 2009, 0904.2736.

[27]  J. Chiang,et al.  THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION , 2009, 0902.1089.

[28]  Heidelberg,et al.  HESS J0632+057: A NEW GAMMA-RAY BINARY? , 2008, 0809.0584.

[29]  John R. Percy.  Understanding Variable Stars , 2007 .

[30]  E. al.,et al.  3.9 day orbital modulation in the TeV gamma-ray flux and spectrum from the X-ray binary LS 5039 , 2006, astro-ph/0607192.

[31]  N Tonello,et al.  Variable Very-High-Energy Gamma-Ray Emission from the Microquasar LS I +61 303 , 2006, Science.

[32]  E. al.,et al.  Discovery of the Binary Pulsar PSR B1259-63 in Very-High-Energy Gamma Rays around Periastron with H.E.S.S , 2005, astro-ph/0506280.

[33]  Jaroslav Nesetril,et al.  Otakar Boruvka on minimum spanning tree problem Translation of both the 1926 papers, comments, history , 2001, Discret. Math..

[34]  Miroslav Morháč,et al.  Identification of peaks in multidimensional coincidence γ-ray spectra , 2000 .