Orbital X-ray modulation study of three Supergiant HMXBs

TL;DR

This study analyzes the orbital X-ray modulation of three supergiant high-mass X-ray binaries using long-term data, accurately determining their orbital periods and revealing unique behaviors and outburst patterns.

Contribution

The paper provides precise orbital period measurements for three HMXBs and identifies new eclipse timings, enhancing understanding of their orbital dynamics and outburst behaviors.

Findings

Orbital period of IGR J18027-2016 is 4.5693 days.

Orbital period of IGR J18483-0311 is 18.5482 days.

Outbursts in IGR J16318-4848 occur approximately every 80 days.

Abstract

We present the orbital X-ray modulation study of three high mass X- ray binary systems, IGR J18027-2016, IGR J18483-0311 and IGR J16318-4848 using data obtained with RXTE-ASM, Swift-BAT and INTEGRAL-ISGRI. Using the long term light curves of the eclipsing HMXB IGR J18027-2016, obtained with Swift-BAT in the energy range 15-50 keV and INTEGRAL-ISGRI in the energy range 22-40 keV, we have determined three new mid eclipse times. The newly determined mid eclipse times together with the known values were used to derive an accurate value of the orbital period of 4.5693(4) d at MJD 52168 and an upper limit of 3.9(1.2)x10^-7 d d^-1 on the period derivative. We have also accurately determined an orbital period of 18.5482(88) d for the intermediate system IGR J18483-0311, which displays an unusual behaviour and shares many properties with the known SFXTs and persistent supergiant systems. This is a transient source and the outbursts occur intermittently at intervals of 18.55 d. Similarly, in the third supergiant system, IGR J16318-4848, we have found that the outbursts are separated by intervals of 80 d or its multiples, suggesting a possible orbital period.