The exotic fraction among unassociated Fermi sources
| dc.contributor.author | Mirabal, N. | |
| dc.contributor.author | Nieto, D. | |
| dc.contributor.author | Pardo, S. | |
| dc.date.accessioned | 2020-09-04T15:47:49Z | |
| dc.date.available | 2020-09-04T15:47:49Z | |
| dc.date.issued | 2010-07-15 | |
| dc.description.abstract | Revealing the nature of unassociated high-energy (> 100 MeV) gamma-ray sources remains a challenge 35 years after their discovery. Of the 934 gamma-ray sources at high Galactic latitude (|b| > 15 degrees) in the First Fermi-LAT catalogue (1FGL), 316 have no obvious associations at other wavelengths. In this paper, we apply the K-means unsupervised classification algorithm to isolate potential counterparts for 18 unassociated Fermi sources contained within a 3000 square degree `overlap region' of the sky intensively covered in radio and optical wavelengths. Combining our results with previous works, we reach potential associations for 119 out of the 128 Fermi sources within said region. If these associations are correct, we estimate that less than 20% of all remaining unassociated 1FGL sources at high Galactic latitude (|b| > 15 degrees) might host `exotic' counterparts distinct from known classes of gamma-ray emitters. Potentially even these outliers could be explained by high-redshift/dust-obscured analogues of the associated sample or by intrinsically faint radio objects. Although such estimate leaves some room for novel discoveries, it severely restricts the possibility of detecting dark matter subhaloes and other unconventional types of gamma-ray emitters in the 1FGL. In closing, we argue that the identification of Fermi sources at the low end of the flux density distribution will be a complex process that might only be achieved through a clever combination of refined classification algorithms, multi-wavelength efforts, and dedicated optical spectroscopy. | en_US |
| dc.description.sponsorship | N.M. gratefully acknowledges support from the Spanish Ministry of Science and Innovation through a Ram´on y Cajal fellowship. We thank Jules Halpern for sharing some of his spectroscopic wizardry with us. We acknowledge useful correspondence with Phil Gregory, David J. Thompson and an anonymous reader. We also acknowledge support from the ConsoliderIngenio 2010 Programme under grant MULTIDARK CSD2009-00064. This paper made use of data from the SDSS. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronau tics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. | en_US |
| dc.description.uri | https://arxiv.org/abs/1007.2644 | en_US |
| dc.format.extent | 7 pages | en_US |
| dc.genre | journal articles preprints | en_US |
| dc.identifier | doi:10.13016/m2snwt-u3iu | |
| dc.identifier.citation | N. Mirabal, D. Nieto, S. Pardo, The exotic fraction among unassociated Fermi sources, Astronomy & Astrophysics manuscript no. fermiaa, https://arxiv.org/abs/1007.2644 | en_US |
| dc.identifier.uri | http://hdl.handle.net/11603/19586 | |
| dc.language.iso | en_US | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology (JCET) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology (CSST)/Center for Research and Exploration in Space Sciences and Technology II (CREST II) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.title | The exotic fraction among unassociated Fermi sources | en_US |
| dc.type | Text | en_US |