206 research outputs found
Optical spectral observations of three binary millisecond pulsars
We present the results of optical spectroscopy of stellar companions to three
binary millisecond pulsars, PSRs J06212514, J23171439 and J23024442,
obtained with the Gran Telescopio Canarias. The spectrum of the J06212514
companion shows a blue continuum and prominent Balmer absorption lines. The
latter are also resolved in the spectrum of the J23171439 companion, showing
that both are DA-type white dwarfs. No spectral features are detected for the
J23024442 companion, however, its broadband magnitudes and the spectral
shape of the continuum emission imply that this is also a DA-type white dwarf.
Based on the spectral analyses, we conclude that the companions of J06212514
and J23171439 are relatively hot, with effective temperatures 8600200 and 96002000~K, respectively, while the J23024442
companion is significantly cooler, 6000~K. We also estimated
the distance to J06212514 of 1.10.3 kpc and argue that its companion
and the companion of J23171439 are He-core white dwarfs providing
constraints on their cooling ages of 2 Gyr.Comment: 9 pages, 8 figures. Paper accepted to MNRA
Optical identification of the binary companion to the millisecond PSR J2302+4442 with the Gran Telescopio Canarias
We report detection of the binary companion to the millisecond pulsar
J2302+4442 based on the deep observations performed with the Gran Telescopio
Canarias. The observations revealed an optical source with =
23.330.02 and =23.080.02, whose position coincides with the
pulsar radio position. By comparing the source colour and magnitudes with the
white dwarf cooling predictions, we found that it likely represents a He or
CO-core white dwarf and estimated its mass of 0.52
M and effective temperature of 6300 K. Combining our
results with the radio timing measurements, we set constraints on the binary
system inclination angle degrees and the pulsar mass
M.Comment: Accepted for publication in MNRA
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