NuSTAR Observations of MAXI J1848-015: disk accretion at low Eddington fraction
Authors/Creators
- 1. Cahill Institute of Astronomy and Astrophysics, Caltech, Pasadena CA, USA
- 2. NASA Goddard Space Flight Center, Greenbelt, MD, USA
- 3. High Energy Astrophysics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan
- 4. Department of Physics, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo, Japan
- 5. Department of Physics, Ehime University, 2-5, Bunkyocho, Matsuyama, Ehime, Japan
- 6. Space Sciences Laboratory, University of California Berkeley, Berkeley CA
Description
We present the results of two NuSTAR observations of the recently discovered source MAXI J1848-015. The source underwent a period of outburst which lasted only around 10 days, during which it showed evidence, including a strong thermal component and broad Fe emission features, for a hot accretion disk which extended to the innermost stable circular orbit around the central accretor. However the observed flux indicated an Eddington fraction of at most ~10^-3. In this luminosity regime, disk accretion near the central object is not expected. We discuss possible scenarios which may lead to this behavior. We also show evidence for a high spin parameter, possibly indicating that the accretor is a black hole, and for disk truncation in the hard state.
Files
microquasars2021_SeanPike.pdf
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(5.4 MB)
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