6533b852fe1ef96bd12aac16

RESEARCH PRODUCT

Finding a 61.0-day orbital period for the HMXB 4U 1036-56 with the Swift-BAT monitoring

N. MasettiV. La ParolaA. SegretoGianpiero TagliaferriGiancarlo CusumanoA. D'ai

subject

High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsSwiftmedia_common.quotation_subjectAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstronomyAstronomy and AstrophysicsAstrophysicsLight curvePower lawlaw.inventionOn boardTelescopeOrbitAtomic orbitalSpace and Planetary ScienceSkylawAstrophysics - High Energy Astrophysical Phenomenacomputermedia_commoncomputer.programming_language

description

Since November 2004, the Burst Alert Telescope on board Swift is producing a monitoring of the entire sky in the 15-150 keV band, recording the timing and spectral behavior of the detected sources. Here we study the properties of the HMXB 4U 1036-56 using both the BAT survey data and those from a Swift-XRT observation. A folding analysis performed on the BAT light curve of the first 100 months of survey unveils a periodic modulation with a period of 61.0 days, tied to the presence in the BAT light curve of several intensity enhancements lasting ~1/4 of P_0. We explain this modulation as the orbital period of the binary system. The position of 4U 1036-56 on the Corbet diagram, the derived semi-major orbit axis (~ 180 R_sun), and the bulk of the source emission observed in a limited portion of the orbit are consistent with a Be companion star. The broad band 0.2-150 keV spectrum is well modeled with a flat absorbed power law with a cut-off at ~16 keV. Finally, we explore the possible association of 4U 1036-56 with the gamma-ray source AGL J1037-5808, finding that the BAT light curve does not show any correlation with the gamma-ray outburst observed in November 2012.

yearjournalcountryeditionlanguage
2013-05-15
10.1093/mnrasl/slt116http://arxiv.org/abs/1305.3610