Search for Extended Sources in the Galactic Plane Using Six Years of Fermi-Large Area Telescope Pass 8 Data above 10 GeV

M Ackermann,E Nuss,T Kamae,F Loparco,C Cecchi,D F Torres,J F Ormes,V Petrosian,P Fusco,G La Mura,L Guillemot,D Costantin,N Omodei,C Sgrò,T A Porter,S J Fegan,S Guiriec,T Mizuno,D J Thompson,M Razzano,J S Perkins,R Desiante,S Cutini,D Simone,D Green,F Spada,T J Brandt,D Paneque,E C Ferrara,P F Michelson,F Giordano,L Di Venere,E D Bloom,E Orlando,S Razzaque,D Malyshev,M Giroletti,E Cavazzuti,R A Cameron,M Caragiulo,J D Magill,W Mitthumsiri,S W Digel,F De Palma,G Chiaro,E J Siskind,K S Wood,C Favuzzi,R Bonino,S Ciprini,E Charles,A Morselli,F Longo,D Bastieri,F Piron,X Hou,S Funk,E Bissaldi,A Chekhtman,S Rainò,E Hays,C C Cheung,G Vianello,R Buehler,J Li,P A Caraveo,J B Thayer,P Spinelli,G Barbiellini,G Tosti,A Franckowiak,M Orienti,A K Harding,S Maldera,N Giglietto,R Bellazzini,F Gargano,D Gasparrini,I V Moskalenko,M Wood,J Bregeon,M E Monzani,D Horan,F Costanza,D J Suson,I A Grenier,G Spandre,E Bottacini,P Lubrano,J Ballet,E Troja,R Rando,J M Cohen,M Ajello,F D’Ammando,D Tak,T Reposeur,M N Mazziotta,M Kuss,T Ohsugi,Pascal Bruel ,Michela Negro ,M Lemoine‐Goumard ,Luca Baldini ,John W Hewitt ,G Jøhannesson ,Melissa Pesce-Rollins ,M.‐H Grondin ,Vaidehi S Paliya ,Giacomo Principe ,A Reimer ,M Peršić ,Stefan Larsson ,Alberto Manfreda ,Yasushi Fukazawa ,Mattia Di Mauro ,Daniel Castro ,Niccolò Di Lalla

doi:10.3847/1538-4357/aa775a

Abstract

Abstract The spatial extension of a γ-ray source is an essential ingredient to determine its spectral properties, as well as its potential multiwavelength counterpart. The capability to spatially resolve γ-ray sources is greatly improved by the newly delivered Fermi-Large Area Telescope (LAT) Pass 8 event-level analysis, which provides a greater acceptance and an improved point-spread function, two crucial factors for the detection of extended sources. Here, we present a complete search for extended sources located within 7° from the Galactic plane, using 6 yr of Fermi-LAT data above 10 GeV. We find 46 extended sources and provide their morphological and spectral characteristics. This constitutes the first catalog of hard Fermi-LAT extended sources, named the Fermi Galactic Extended Source Catalog, which allows a thorough study of the properties of the Galactic plane in the sub-TeV domain.

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