Issue |
A&A
Volume 627, July 2019
|
|
---|---|---|
Article Number | A39 | |
Number of page(s) | 6 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/201935442 | |
Published online | 27 June 2019 |
Effects of Compton scattering on the neutron star radius constraints in rotation-powered millisecond pulsars
1
Tuorla Observatory, Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
e-mail: thjsal@utu.fi
2
Institut für Astronomie und Astrophysik, Kepler Center for Astro and Particle Physics, Universität Tübingen, Sand 1, 72076 Tübingen, Germany
3
Astronomy Department, Kazan (Volga region) Federal University, Kremlyovskaya str. 18, 420008 Kazan, Russia
4
Space Research Institute of the Russian Academy of Sciences, Profsoyuznaya str. 84/32, 117997 Moscow, Russia
5
Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, 10691 Stockholm, Sweden
Received:
11
March
2019
Accepted:
15
May
2019
The aim of this work is to study the possible effects and biases on the radius constraints for rotation-powered millisecond pulsars when using Thomson approximation to describe electron scattering in the atmosphere models, instead of using exact formulation for Compton scattering. We compare the differences between the two models in the energy spectrum and angular distribution of the emitted radiation. We also analyse a self-generated, synthetic, phase-resolved energy spectrum, based on Compton atmosphere and the most X-ray luminous, rotation-powered millisecond pulsars observed by the Neutron star Interior Composition ExploreR (NICER). We derive constraints for the neutron star parameters using both the Compton and Thomson models. The results show that the method works by reproducing the correct parameters with the Compton model. However, biases are found in both the size and the temperature of the emitting hotspot, when using the Thomson model. The constraints on the radius are still not significantly changed, and therefore the Thomson model seems to be adequate if we are interested only in the radius measurements using NICER.
Key words: stars: atmospheres / stars: neutron / X-rays: binaries / X-rays: stars
© ESO 2019
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.