CONSTRAINTS ON THE MASS AND RADIUS OF THE ACCRETING NEUTRON STAR IN THE RAPID BURSTER

Journal Article · Wed Jun 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/752/2/158· OSTI ID:22036983

Sala, G; Jose, J; Parikh, A; Longland, R ^[1]; Haberl, F ^[2]; Pardo, L C ^[3]; Andersen, M ^[4]

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1. Departament de Fisica i Enginyeria Nuclear, EUETIB, Universitat Politecnica de Catalunya, c/ Comte d'Urgell 187, E-08036 Barcelona (Spain)
2. Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany)
3. Grup de Caracteritzacio de Materials, Departament de Fisica i Enginyeria Nuclear, ETSEIB, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona, Catalonia (Spain)
4. Research and Scientific Support Department, European Space Agency, ESTEC, Keplerlaan 1, NL-2200 AG Noordwijk (Netherlands)

The Rapid Burster (MXB 1730-335) is a unique object, showing both type I and type II X-ray bursts. A type I burst of the Rapid Burster was observed with Swift/X-Ray Telescope on 2009 March 5, showing photospheric radius expansion (PRE) for the first time in this source. We report here on the mass and radius determination from this PRE burst using a Bayesian approach. After marginalization over the likely distance of the system (5.8-10 kpc), we obtain M = 1.1 {+-} 0.3 M{sub Sun} and R = 9.6 {+-} 1.5 km (1{sigma} uncertainties) for the compact object, ruling out the stiffest equations of state for the neutron star. We study the sensitivity of the results to the distance, the color correction factor, and the hydrogen mass fraction in the envelope. We find that only the distance plays a crucial role.

• OSTI ID: 22036983
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 752; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
BINARY STARS
COLOR
CORRECTIONS
COSMIC X-RAY BURSTS
DISTANCE
EQUATIONS OF STATE
GAMMA ASTRONOMY
HYDROGEN
MASS
NEUTRON STARS
SENSITIVITY
X RADIATION