MASS/RADIUS CONSTRAINTS ON THE QUIESCENT NEUTRON STAR IN M13 USING HYDROGEN AND HELIUM ATMOSPHERES
- Department of Physics, University of Alberta, Room 238 CEB, Edmonton, AB T6G 2G7 (Canada)
- School of Mathematics, University of Southampton, Southampton SO17 1BJ (United Kingdom)
The mass and radius of the neutron star (NS) in low-mass X-ray binaries can be obtained by fitting the X-ray spectrum of the NS in quiescence, and the mass and radius constrains the properties of dense matter in NS cores. A critical ingredient for spectral fits is the composition of the NS atmosphere: hydrogen atmospheres are assumed in most prior work, but helium atmospheres are possible if the donor star is a helium white dwarf. Here we perform spectral fits to XMM-Newton, Chandra, and ROSAT data of a quiescent NS in the globular cluster M13. This NS has the smallest inferred radius from previous spectral fitting. Assuming an atmosphere composed of hydrogen, we find a significantly larger radius, more consistent with those from other quiescent NSs. With a helium atmosphere (an equally acceptable fit), we find even larger values for the radius.
- OSTI ID:
- 22167725
- Journal Information:
- Astrophysical Journal, Vol. 764, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
THE IMPACT OF SURFACE TEMPERATURE INHOMOGENEITIES ON QUIESCENT NEUTRON STAR RADIUS MEASUREMENTS
NEUTRON STAR RADIUS MEASUREMENT WITH THE QUIESCENT LOW-MASS X-RAY BINARY U24 IN NGC 6397