THE MASS AND RADIUS OF THE NEUTRON STAR IN EXO 1745−248

By F. Özel, T. Güver, Dimitrios Psaltis. 2008

215 citations recorded by the source corpus.

Bursting X-ray binaries in globular clusters are ideal sources for measuring neutron star masses and radii, and hence, for determining the equation of state of cold, ultradense matter. We use time-resolved spectroscopic data from EXO 1745−248 during thermonuclear bursts that show strong evidence for photospheric radius expansion to measure the Eddington flux and the apparent surface area of the neutron star. We combine this with the recent measurement of the distance to the globular cluster Terzan 5, where this source resides, to measure the neutron star mass and radius. We find tightly constrained pairs of values for the mass and radius, which are centered around M = 1.4 M☉ and R = 11 km or around M = 1.7 M☉ and R = 9 km. These values favor nucleonic equations of state with symmetry energy that is relatively low and has a weak dependence on density.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/3e543b6abb7b7a18a2a31e1f26f3937c512a5414

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Lattimer
2. A. Steiner
3. F. Özel
4. S. Guillot
5. T. Güver
6. C. Heinke
7. Dimitrios Psaltis
8. E. Brown

Citations in the corpus

• Constraining the mass and radius of neutron stars in globular clusters (2017, background): “Steiner et al. (2010) combined mass-radius constraints from three thermonuclear burst systems (Özel et al. 2009; Güver et al. 2010a,b) with results from three quiescent LMXBs (Heinke et al. 2006b; Webb & Barret 2007).”
• ON THE MASS DISTRIBUTION AND BIRTH MASSES OF NEUTRON STARS (2012, unknown): “This category includes 4U 1745−248 (Özel et al. 2009), 4U 1608−52 (Güver et al. 2010a), 4U 1820−30 (Güver et al. 2010b), and KS 1731−260 (Özel et al. 2012).”
• Neutron star mass and radius measurements from atmospheric model fits to X-ray burst cooling tail spectra (2017, methodology): “…mass M and the circumferential radius R from burst cooling tails, both of which stem from the earlier work: the touchdown method (e.g., Özel 2006; Özel et al. 2009; Güver et al. 2010; Özel et al. 2016) and the cooling tail method (e.g., Suleimanov et al. 2011a; Poutanen et al. 2014; Nättilä et…”
• THE NEUTRON STAR MASS DISTRIBUTION (2010, background): “NSs in X-ray binaries also show systematic deviations from the canonical mass limit (e.g., van Kerkwijk et al. 1995; Barziv et al. 2001; Quaintrell et al. 2003; van der Meer et al. 2005; Özel et al. 2009; Güver et al. 2010).”
• MEASUREMENT OF THE RADIUS OF NEUTRON STARS WITH HIGH SIGNAL-TO-NOISE QUIESCENT LOW-MASS X-RAY BINARIES IN GLOBULAR CLUSTERS (2012, unknown): “The LMXBs EXO 1745-248, 4U 1608-52, and 4U 1820- 30 were found to have respective radii in the 2σ ranges RNS = [7.5 − 11.0] km (Özel et al. 2009), RNS = [7.5 − 11.5] km (Güver et al. 2010a) and RNS = [8.5 − 9.5] km (Güver et al. 2010b), respectively.”
• Constraints on perturbative f(R) gravity via neutron stars (2010, methodology): “These data are provided by the measurements on the neutron stars EXO 1745-248 [44], 4U 1608-52 [45] and 4U 1820-30 [46] by the methods described in the cited papers.”
• THE DENSE MATTER EQUATION OF STATE FROM NEUTRON STAR RADIUS AND MASS MEASUREMENTS (2015, methodology): “Spectroscopic observations of thermonuclear bursts from accreting neutron stars with the last generation of X-ray telescopes have provided measurements of both the radii and the masses of several sources with weakly correlated uncertainties (e.g., Özel et al. 2009, 2012; Güver et al.”
• THE MASS AND RADIUS OF THE NEUTRON STAR IN 4U 1820−30 (2010, methodology): “Comparing with the two measurements of neutron star masses and radii we reported earlier using the present method (Özel et al. 2009; Güver et al. 2010), we note that the neutron star in 4U1820−30 has the smallest mass of the three (although the three span a relatively narrow range), while its…”
• THE DISTANCE, MASS, AND RADIUS OF THE NEUTRON STAR IN 4U 1608−52 (2008, methodology): “Following the analysis in Özel et al. (2009), we used either the Science Event mode data with the E_125μs_64M_0_1s configuration, which has a nominal time resolution of 125 μs in 64 spectral channels, or we used Good Xenon mode data which has 0.95 μs time resolution in 256 spectral channels, where…”