INTEGRAL and Swift observations of the Be X-ray binary 4U 1036-56 (RX J1037.5-5647) and its possible relation with gamma-ray transients

TL;DR

This study analyzes the X-ray behavior of the high mass X-ray binary 4U 1036-56 using INTEGRAL and Swift data, revealing its quiescent and outburst states, pulse period, and potential link to gamma-ray transients.

Contribution

It provides the first detailed timing and spectral analysis of 4U 1036-56 with new observations and explores its possible association with gamma-ray transients.

Findings

4U 1036-56 is a weak X-ray source mostly in quiescence with occasional outbursts.

Detected pulse period at approximately 855 seconds during an outburst.

Possible positional correlation with unidentified gamma-ray transients.

Abstract

We present timing, spectral, and long-term temporal analysis of the high mass X-ray binary (HMXB) 4U 1036-56 using INTEGRAL and Swift observations. We show that it is a weak hard X-ray source spending a major fraction of the time in quiescence, and only occasionally characterized by X-ray outbursts. The outburst activity we report here lasts several days, with a dynamic range spanned by the luminosity in quiescence and in outburst as high as ~30. We report the detection of pulse period at 854.75+/-4.39 s during an outburst, which is consistent with previous measurements. Finally, we analyze the possibility of 4U 1036--56's association with the unidentified transient gamma-ray sources AGL J1037--5708 & GRO J1036--55, as prompted by its positional correlation.