PI: Shriharsh Tendulkar, Caltech Astronomy, email@example.com
Address: MS 249-17, Pasadena, CA, 91125, USA
CoI: David Kaplan, University of Wisconsin at Madison (Astronomy)
CoI: Kevin Stovall, University of New Mexico
Title: Solving the dilemma of PSR J0214+5222's companion
Abstract: PSR J0214+5222 is a new 24.5-ms pulsar in a nearly-circular 512-day orbit around a low-mass ( 0.5 Msun) companion. Previous photometry from the 0.9 m WIYN telescope detected an optical counterpart with B=21.48+/-0.06 mag and R=21.72+/-0.09 mag, with an estimated temperature of 26000 K - possibly the hottest recycled pulsar companion known! These results lead to a dilemma about the likely nature of the companion of the pulsar. If the companion were a hot white-dwarf, the cooling age would be inconsistent with the pulsar spindown age by a factor of 10-100. Alternatively, a core helium burning sub-dwarf star would require the dispersion measure distance to be larger by a factor of 2, perhaps indicating a breakdown of the NE2001 Galactic electron distribution model along this line of sight. These scenarios can be easily discriminated on the basis of the surface gravity of these objects (log(g)<6 for an sub-dwarf star, and 7<log(g)<9 for low to high mass white dwarfs). In this proposal, we request precise photometry and spectroscopy of this target to constrain the surface gravity, effective temperature and flux of the companion, thereby finalizing the identity of the companion. If confirmed, this would be the first pulsar-sub dwarf star binary ever discovered.
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