Optical counterparts of two Fermi millisecond pulsars: PSR J1301+0833 and PSR J1628–3205

Journal Article · Mon Nov 10 04:00:00 EST 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/795/2/115· OSTI ID:22370245

Li, Miao; Halpern, Jules P. ^[1]

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1. Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

Using the 1.3 m and 2.4 m Telescopes of the MDM Observatory, we identified the close companions of two eclipsing millisecond radio pulsars that were discovered by the Green Bank Telescope in searches of Fermi Gamma-ray Space Telescope sources, and measured their light curves. PSR J1301+0833 is a black widow pulsar in a 6.5 hr orbit whose companion star is strongly heated on the side facing the pulsar. It varies from R = 21.8 to R > 24 around the orbit. PSR J1628–3205 is a 'redback', a nearly Roche-lobe-filling system in a 5.0 hr orbit whose optical modulation in the range 19.0 < R < 19.4 is dominated by strong ellipsoidal variations, indicating a large orbital inclination angle. PSR J1628–3205 also shows evidence for a long-term variation of about 0.2 mag, and an asymmetric temperature distribution possibly due to either off-center heating by the pulsar wind, or large starspots. Modeling of its light curve restricts the inclination angle to i > 55°, the mass of the companion to 0.16 < M{sub c} < 0.30 M {sub ☉}, and the effective temperature to 3560 < T {sub eff} < 4670 K. As is the case for several redbacks, the companion of PSR J1628–3205 is less dense and hotter than a main-sequence star of the same mass.

• OSTI ID: 22370245
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 795; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASYMMETRY
ECLIPSE
GAMMA RADIATION
HEATING
INCLINATION
MAIN SEQUENCE STARS
ORBITS
PULSARS
ROCHE EQUIPOTENTIALS
SIMULATION
SPACE
STELLAR WINDS
TELESCOPES
TEMPERATURE DISTRIBUTION
VISIBLE RADIATION