MEASURING NEUTRON STAR RADII VIA PULSE PROFILE MODELING WITH NICER
- Astronomy Department, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)
- Center for Research and Exploration in Space Science and Technology/USRA, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)
- Department of Physics, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2E1 (Canada)
The Neutron-star Interior Composition Explorer is an X-ray astrophysics payload that will be placed on the International Space Station . Its primary science goal is to measure with high accuracy the pulse profiles that arise from the non-uniform thermal surface emission of rotation-powered pulsars. Modeling general relativistic effects on the profiles will lead to measuring the radii of these neutron stars and to constraining their equation of state. Achieving this goal will depend, among other things, on accurate knowledge of the source, sky, and instrument backgrounds. We use here simple analytic estimates to quantify the level at which these backgrounds need to be known in order for the upcoming measurements to provide significant constraints on the properties of neutron stars. We show that, even in the minimal-information scenario, knowledge of the background at a few percent level for a background-to-source countrate ratio of 0.2 allows for a measurement of the neutron star compactness to better than 10% uncertainty for most of the parameter space. These constraints improve further when more realistic assumptions are made about the neutron star emission and spin, and when additional information about the source itself, such as its mass or distance, are incorporated.
- OSTI ID:
- 22667164
- Journal Information:
- Astrophysical Journal, Vol. 832, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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