INTEGRAL OBSERVATIONS OF THE {gamma}-RAY BINARY 1FGL J1018.6-5856
- Laboratory for Particle Astrophysics, Institute of High Energy Physics, Beijing 100049 (China)
- Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain)
- AIM, UMR 7158 CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d'Astrophysique, Saclay, 91191 Gif-sur-Yvette Cedex (France)
- Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, Torre C5, 2a planta, 08193 Barcelona (Spain)
The Fermi Large Area telescope (Fermi-LAT) collaboration has recently reported that one of their detected sources, namely, 1FGL J1018.6-5856, is a new gamma-ray binary similar to LS 5039. This has prompted efforts to study its multi-frequency behavior. In this report, we present the results from 5.78 Ms International Gamma-Ray Astrophysics Laboratory (INTEGRAL) IBIS/ISGRI observations on the source 1FGL J1018.6-5856. By combining all the available INTEGRAL data, a detection is made at a significance level of 5.4{sigma} in the 18-40 keV band, with an average intensity of 0.074 counts s{sup -1}. However, we find that there is non-statistical noise in the image that effectively reduces the significance to about 4{sigma} and a significant part of the signal appears to be located in a 0.2-wide phase region, at phases 0.4-0.6 (where even the corrected significance amounts to 90% of the total signal found). Given the scarcity of counts, a variability is hinted at about 3{sigma} at the hard X-rays, with an anticorrelation with the Fermi-LAT periodicity. If this behavior were true, it would be similar to that found in LS 5039 and prompt observations with TeV telescopes at phases anticorrelated with the GeV maximum.
- OSTI ID:
- 21562423
- Journal Information:
- Astrophysical Journal Letters, Vol. 738, Issue 2; Other Information: DOI: 10.1088/2041-8205/738/2/L31; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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