A NuSTAR OBSERVATION OF THE GAMMA-RAY-EMITTING X-RAY BINARY AND TRANSITIONAL MILLISECOND PULSAR CANDIDATE 1RXS J154439.4–112820

Journal Article · Wed Jul 20 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/826/1/28· OSTI ID:22666064

Bogdanov, Slavko ^[1]

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1. Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

I present a 40 ks Nuclear Spectroscopic Telescope Array observation of the recently identified low-luminosity X-ray binary and transitional millisecond pulsar (tMSP) candidate 1RXS J154439.4 112820, which is associated with the high-energy γ -ray source 3FGL J1544.6 1125. The system is detected up to ∼30 keV with an extension of the same power-law spectrum and rapid large-amplitude variability between two flux levels observed in soft X-rays. These findings provide further evidence that 1RXS J154439.4 112820 belongs to the same class of objects as the nearby bona fide tMSPs PSR J1023+0038 and XSS J12270 4859 and therefore almost certainly hosts a millisecond pulsar accreting at low luminosity. I also examine the long-term accretion history of 1RXS J154439.4 112820 based on archival optical, ultraviolet, X-ray, and γ -ray light curves covering approximately the past decade. Throughout this period, the source has maintained similar flux levels at all wavelengths, which is an indication that it has not experienced prolonged episodes of a non-accreting radio pulsar state but may spontaneously undergo such events in the future.

• OSTI ID: 22666064
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 826; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AMPLITUDES
APPROXIMATIONS
COSMIC GAMMA SOURCES
GAMMA RADIATION
KEV RANGE
LUMINOSITY
NEUTRONS
PULSARS
SOFT X RADIATION
SPECTRA
STARS
TELESCOPES
ULTRAVIOLET RADIATION
VISIBLE RADIATION
WAVELENGTHS