Using X-ray continuum-fitting to estimate the spin of MAXI J1305-704
Abstract
MAXI J1305-704 is a transient X-ray binary with a black hole primary. It was discovered on 2012 April 9, during its only known outburst. MAXI J1305-704 is also a high inclination low-mass X-ray binary with prominent dip features in its light curves, so we check the full catalogue of 92 Swift/XRT continuous observations of MAXI J1305-704, focusing only on the stable spectra. We select 13 'gold' spectra for which the rms <0.075 and the coronal scattered fraction $f_{\mathrm{sc}} \lesssim 25$ per cent. These 'gold' data are optimal thermal-state observations for continuum-fitting modelling, in which the disc extends to the innermost stable circular orbit and is geometrically thin. The black hole spin was unknown for this object before. By utilizing the X-ray continuum fitting method with the relativistic thin disc model kerrbb2 and supplying the known dynamical binary system parameters, we find MAXI J1305-704 has a moderate spin ($a_{*}=0.87_{-0.13}^{+0.07}$) at a 68.3 per cent confidence level. This is the first determination of MAXI J1305-704's spin.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2023
- DOI:
- 10.1093/mnras/stad442
- arXiv:
- arXiv:2212.04653
- Bibcode:
- 2023MNRAS.520.5803F
- Keywords:
-
- black hole physics;
- X-rays: binaries;
- stars: individual: MAXI J1305-704;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 13 pages, 10 figures, submitted to MNRAS