@article{e42e866fff4442f5b9b11600d7b74155,
title = "BL Lacertae identifications in a ROSAT-selected sample of Fermi unidentified objects",
abstract = "The optical spectroscopic followup of 27 sources belonging to a sample of 30 high-energy objects selected by positionally cross correlating the first Fermi/LAT Catalog and the ROSAT All-Sky Survey Bright Source Catalog is presented here. It has been found or confirmed that 25 of them are BL Lacertae objects (BL Lacs), while the remaining two are Galactic cataclysmic variables (CVs). This strongly suggests that the sources in the first group are responsible for the GeV emission detected with Fermi, while the two CVs most likely represent spurious associations. We thus find an 80% a posteriori probability that the sources selected by matching GeV and X-ray catalogs belong to the BL Lac class. We also show suggestions that the BL Lacs selected with this approach are probably high-synchrotron-peaked sources and in turn good candidates for the detection of ultra-high-energy (TeV) photons from them.",
author = "N. Masetti and B. Sbarufatti and P. Parisi and E. Jim{\'e}nez-Bail{\'o}n and V. Chavushyan and Vogt, {F. P.A.} and V. Sguera and Stephen, {J. B.} and E. Palazzi and L. Bassani and A. Bazzano and M. Fiocchi and G. Galaz and R. Landi and A. Malizia and D. Minniti and L. Morelli and P. Ubertini",
note = "Funding Information: We thank Francesca Ghinassi and Avet Harutyunyan for Service Mode observations at the TNG; Duncan Castex and Ariel S{\'a}nchez for assistance at the ESO NTT; Manuel Hern{\'a}ndez for Service Mode observations at the CTIO telescope and Fred Walter for coordinating them. N.M. thanks Ivo Saviane, Valentin Ivanov and Roberto Soria for help with data acquisition, Paola Grandi for useful discussions, and Francesco Massaro for help with the preparation of Fig. 8. We also thank the anonymous referee for useful remarks which helped us to improve the quality of this paper. This research has made use of the ASI Science Data Center Multimission Archive and of data obtained from the ESO Science Archive Facility; it also used the NASA Astrophysics Data System Abstract Service, the NASA/IPAC Extragalactic Database (NED), and the NASA/IPAC Infrared Science Archive, which are operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This publication made use of data products from the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This research has also made use of the SIMBAD and VIZIER databases operated at CDS, Strasbourg, France. N.M. thanks the Departamento de Astronom{\'i}a y Astrof{\'i}sica of the Pontificia Universidad Cat{\'o}lica de Chile in Santiago for the warm hospitality during the preparation of this paper. P.P. and R.L. are supported by the ASI-INAF agreement No. I/033/10/0. D.M. is supported by the BASAL CATA PFB-06 and FONDECYT No. 1130196 grants. G.G. is supported by Fondecyt grant No. 1120195.",
year = "2013",
doi = "10.1051/0004-6361/201322611",
language = "English (US)",
volume = "559",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}