Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2011-10-03
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
Scientific paper
PSR J1903+0327 is a mili-second pulsar with a mass of 1.67 M_{\odot} in a highly eccentric orbit (e=0.44) around a main-sequence star. This unique system cannot be reconciled with current observations where milli-second pulsars are generally seen to orbit white dwarfs in almost exactly circular orbits. Current theoretical models of binary and stellar formation and evolution cannot explain the high eccentricity of this system either. In this work, we present three new epochs of optical spectroscopy for the companion to PSR J1903+0327, obtained to confirm the association of the main-sequence star with the pulsar. These 3 new epochs together with the 2 previous ones obtained by Freire et al. (2011) firmly establish the high eccentricity of the companion's orbit as predicted by pulsar timing. Using all five epochs of optical data, we have provided an independent estimate of the mass-ratio, R=1.56\pm0.15 as well as the systemic radial velocity of the binary, \gamma= 42.1\pm2.5 km/s. We constrain the spectral type of the pulsar companion to lie between F5 V -- G0 V (a slightly earlier type than suggested previously) by measuring the equivalent widths of two of the three Ca-triplet lines (8498 \AA, 8542 \AA) and the Paschen line at 8598 \AA (P14); we also broadly constrain the metallicity of the companion. Additionally, we have placed a somewhat better limit on the rotational velocity of the pulsar companion of v_{rot}\sin{i} \leq 66 km/s which is still not sufficient to allow a test of general relativity using this system.
Froning Cynthia S.
Gopakumar Achamveedu
Joshi Bhal Chandra
Khargharia Juthika
Stocke John T.
No associations
LandOfFree
PSR J1903+0327 : A Unique Milli-Second Pulsar with a Main-Sequence Companion Star does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with PSR J1903+0327 : A Unique Milli-Second Pulsar with a Main-Sequence Companion Star, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PSR J1903+0327 : A Unique Milli-Second Pulsar with a Main-Sequence Companion Star will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-267144