Abstract
We present NuSTAR and Swift observations of the neutron star Aquila X-1 during the peak of its 2014 July outburst. The spectrum is soft with strong evidence for a broad Fe Kα line. Modeled with a relativistically broadened reflection model, we find that the inner disk is truncated with an inner radius of 15 ± 3RG. The disk is likely truncated by either the boundary layer and/or a magnetic field. Associating the truncated inner disk with pressure from a magnetic field gives an upper limit of B<5 ± 2x108. Although the radius is truncated far from the stellar surface, material is still reaching the neutron star surface as evidenced by the X-ray burst present in the NuSTAR observation.
Original language | English |
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Journal | The Astrophysical Journal Letters |
Volume | 819 |
Issue number | 2 |
Pages (from-to) | L29 |
Number of pages | 6 |
ISSN | 2041-8205 |
DOIs | |
Publication status | Published - 2016 |
Keywords
- Accretion
- Accretion disks
- Magnetic fields
- Stars: neutron
- X-rays: binaries
- X-rays: bursts