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

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 ofmore » PSR J1628–3205 is less dense and hotter than a main-sequence star of the same mass.« less
Authors:
;  [1] ;  [2]
  1. Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)
  2. Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)
Publication Date:
OSTI Identifier:
22370245
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 795; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; ECLIPSE; GAMMA RADIATION; HEATING; INCLINATION; MAIN SEQUENCE STARS; ORBITS; PULSARS; ROCHE EQUIPOTENTIALS; SIMULATION; SPACE; STELLAR WINDS; TELESCOPES; TEMPERATURE DISTRIBUTION; VISIBLE RADIATION