Herding StrayCats: A Study of Neutron Star Low-mass X-ray Binaries with NuSTAR Stray Light
Abstract
Neutron stars (NSs) are the densest observable objects with a surface in the Universe. The matter inside of a NS exists in an ultra-dense (more than 2 times the density of an atomic nucleus), cold (the available thermal energy is less than the Coulomb energy per nucleon) state that cannot be reproduced in Earth-based laboratories. Therefore, the behavior of material under these conditions remains a mystery that can only be solved through observing and studying NSs. Some NSs exist in low-mass X-ray binaries (LMXBs), which have a stellar companion that is roughly the size of the Sun and are able to undergo mass transfer via Roche-lobe overflow. These systems present the ideal environment to learn more about accretion physics and properties of NSs. Thanks to the open geometry construct of NuSTAR, serendipitous observations of bright X-ray sources occur frequently in "stray light" (i.e., X-ray photons that have not passed through the focusing optics) when NuSTAR observes near the galactic plane. There are over 16 Ms of data on NS LMXBs that have yet to be analyzed. This project aims to utilize the available archival stray light data to map out the accretion geometry and other key parameters in accreting NS LMXBs.
- Publication:
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NASA ADAP Proposal
- Pub Date:
- 2022
- Bibcode:
- 2022adap.prop..125H