X-RAY VARIABILITY AND EVIDENCE FOR PULSATIONS FROM THE UNIQUE RADIO PULSAR/X-RAY BINARY TRANSITION OBJECT FIRST J102347.6+003841

Journal Article · Sun Oct 10 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/722/1/88· OSTI ID:21464671

Archibald, Anne M; Kaspi, Victoria M; Bogdanov, Slavko ^[1]; Hessels, Jason W. T. ^[2]; Stairs, Ingrid H ^[3]; Ransom, Scott M ^[4]

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1. Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada)
2. Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands)
3. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)
4. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22901 (United States)

We report on observations of the unusual neutron-star binary system FIRST J102347.6+003841 carried out using the XMM-Newton satellite. This system consists of a radio millisecond pulsar (PSR J1023+0038) in a 0.198 day orbit with a {approx}0.2 M{sub sun} Roche-lobe-filling companion and appears to have had an accretion disk in 2001. We observe a hard power-law spectrum ({Gamma} = 1.26(4)) with a possible thermal component, and orbital variability in X-ray flux and possibly hardness of the X-rays. We also detect probable pulsations at the pulsar period (single-trial significance {approx}4.5{sigma} from an 11(2)% modulation), which would make this the first system in which both orbital and rotational X-ray pulsations are detected. We interpret the emission as a combination of X-rays from the pulsar itself and from a shock where material overflowing the companion meets the pulsar wind. The similarity of this X-ray emission to that seen from other millisecond pulsar binary systems, in particular 47 Tuc W (PSR J0024 - 7204W) and PSR J1740 - 5340, suggests that they may also undergo disk episodes similar to that seen in J1023 in 2001.

• OSTI ID: 21464671
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 722; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
COSMIC RADIO SOURCES
EMISSION
NEUTRON STARS
ORBITS
POTENTIALS
PULSARS
ROCHE EQUIPOTENTIALS
SATELLITES
STARS