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The Outbursts and Orbit of the Accreting Pulsar GS 1843-02=1845-024

Finger, Mark H. and Bildsten, Lars and Chakrabarty, Deepto and Prince, Thomas A. and Scott, D. Matthew and Wilson, Colleen A. and Zhang, S. Nan (1999) The Outbursts and Orbit of the Accreting Pulsar GS 1843-02=1845-024. Astrophysical Journal, 517 (1). pp. 449-459. ISSN 0004-637X. doi:10.1086/307191.

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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.

Item Type:Article
Related URLs:
URLURL TypeDescription
Chakrabarty, Deepto0000-0001-8804-8946
Prince, Thomas A.0000-0002-8850-3627
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.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Subject Keywords:accretion, accretion disks; binaries: general; pulsars: individual (GS 1843–02, 2S 1845–024); stars: emission-line, Be; stars: neutron
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Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1999-61
Issue or Number:1
Record Number:CaltechAUTHORS:20150218-145949704
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:54955
Deposited By: Deborah Miles
Deposited On:24 Feb 2015 23:47
Last Modified:10 Nov 2021 20:39

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