2015ApJ...798...56L -
Astrophys. J., 798, 56 (2015/January-1)
An ultra-low-mass and small-radius compact object in 4U 1746-37?
LI Z., QU Z., CHEN L., GUO Y., QU J. and XU R.
Abstract (from CDS):
Photospheric radius expansion (PRE) bursts have already been used to constrain the masses and radii of neutron stars. RXTE observed three PRE bursts in 4U 1746-37, all with low touchdown fluxes. We discuss here the possibility of a low-mass neutron star in 4U 1746-37 because the Eddington luminosity depends on stellar mass. With typical values of hydrogen mass fraction and color correction factor, a Monte Carlo simulation was applied to constrain the mass and radius of a neutron star in 4U 1746-37. 4U 1746-37 has a high inclination angle. Two geometric effects, the reflection of the far-side accretion disk and the obscuration of the near-side accretion disk, have also been included in the mass and radius constraints of 4U 1746-37. If the reflection of the far-side accretion disk is accounted for, a low-mass compact object (mass of 0.41±0.14 M☉ and radius of 8.73±1.54 km at 68% confidence) exists in 4U 1746-37. If another effect operated, 4U 1746-37 may contain an ultra-low-mass and small-radius object (M = 0.21±0.06 M☉, R = 6.26±0.99 km at 68% confidence). Combining all possibilities, the mass of 4U 1746-37 is 0.41–0.30+0.70M☉ at 99.7% confidence. For such low-mass neutron stars, it could be reproduced by a self-bound compact star, i.e., a quark star or quark-cluster star.
Abstract Copyright:
∼
Journal keyword(s):
binaries: general - stars: individual: 4U 1746-37 - stars: neutron - X-rays: binaries - X-rays: individual: 4U 1746-37 - X-rays: stars
Simbad objects:
11
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2015ApJ...798...56L and select 'bookmark this link' or equivalent in the popup menu