The Outbursts and Orbit of the Accreting Pulsar GS 1843-02=1845-024
Abstract
We present observations of a series of 10 outbursts of pulsed hard X-ray flux from the transient 10.6 mHz accreting pulsar GS 1843-02, using the Burst and Transient Source Experiment on the Compton Gamma Ray Observatory. These outbursts occurred regularly every 242 days, coincident with the ephemeris of the periodic transient GRO J1849-03, which has recently been identified with the SAS 3 source 2S 1845-024. Our pulsed detection provides the first clear identification of GS 1843-02 with 2S 1845-024. We present a pulse timing analysis that shows that the 2S 1845-024 outbursts occur near the periastron passage of the neutron star's highly eccentric (e=0.88 ± 0.01) 242.18 ± 0.01 day period binary orbit about a high-mass (M_c>7 M_☉) companion. The orbit and transient outburst pattern strongly suggest that the pulsar is in a binary system with a Be star. Our observations show a long-term spin-up trend, with most of the spin-up occurring during the outbursts. From the measured spin-up rates and inferred luminosities we conclude that an accretion disk is present during the outbursts.
Additional Information
© 1999. The American Astronomical Society. Received 1998 September 28; accepted 1999 December 29. M. H. F. acknowledges support from NASA grant NAG5-4238. L. B. and T. A. P. acknowledge support from NASA grant NAGW-4517. We thank the anonymous referee for helpful comments, which have improved the text.Attached Files
Published - 1999-61.pdf
Files
Name | Size | Download all |
---|---|---|
md5:2228dfccfbb8afcd3b2d6f2a755df26c
|
276.0 kB | Preview Download |
Additional details
- Eprint ID
- 54955
- Resolver ID
- CaltechAUTHORS:20150218-145949704
- NASA
- NAG5-4238
- NASA
- NAGW-4517
- Created
-
2015-02-24Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 1999-61