We report on radio and X-ray observations of PSR J1832+0029 , a 533-ms radio pulsar discovered in the Parkes Multibeam Pulsar Survey .
From radio observations taken with the Parkes , Lovell and Arecibo telescopes , we show that this pulsar exhibits two spindown states akin to PSRs B1931+24 reported by Kramer et al .
and J1841 - 0500 reported by Camilo et al .
Unlike PSR B1931+24 , which switches between “ on ” and “ off ” states on a 30–40 day time-scale , PSR J1832+0029 is similar to PSR J1841 - 0500 in that it spends a much longer period of time in the off-state .
So far , we have fully sampled two off-states .
The first one lasted between 560 and 640 days and the second one lasted between 810 and 835 days .
From our radio timing observations , the ratio of on/off spindown rates is 1.77 \pm 0.03 . Chandra observations carried out during both the on- and off-states of this pulsar failed to detect any emission .
Our results challenge but do not rule out models involving accretion onto the neutron star from a low-mass stellar companion .
In spite of the small number of intermittent pulsars currently known , difficulties in discovering them and in quantifying their behavior imply that their total population could be substantial .