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Discovery of radio emission from X-ray pulsar PSR J1852+0040

ATel #501; V. M. Malofeev (PRAO LPI, Pushchino), O. I. Malov (PRAO LPI, Pushchino), D. A. Teplykh (PRAO LPI, Pushchino), A. P. Glushak (PRAO LPI, Pushchino)
on 27 May 2005; 07:23 UT
Credential Certification: V. M. Malofeev (malofeev@prao.psn.ru)

Subjects: Radio, X-ray, Neutron Star, Supernova Remnant, Transient, Pulsar

Referred to by ATel #: 510

We report the detection of radio pulses from X-ray pulsar J1852+0040 with the same period (105 ms) at frequency 111.23 MHz. This pulsar was discovered in March 2005 by Gotthelf et al. (astro-ph/0503424) in the compact central object (CCO) of the young supernova remnant Kes 79 using XMM-Newton observations.

Our observations were made during 24 days in April-May 2005 using the Large Phased Array in Pushchino Radio Astronomy Observatory (PRAO, Russia), sensitive transit radio telescope consisting of 16384 dipoles and on operating frequency of 110.5 +/- 1.5 MHz. We used multi-channel receiver with 48 or 32 channels, where the individual channel had a width equal to 20 or 5 kHz. Pulsar signal (S/N>6) was detected in the half of days with the integration of 1647 pulses for each day. The width of the integration profile at 50 percent of the intensity maximum is <25 ms, that is about two times less than in X-ray one. We can not give more precise value of the pulse width, if we take into account the possible broadening of the pulsar shape in the interstellar medium at 111 MHz. The estimate for the dispersion measure 110 +/- 3 pc/cm^{3} places the pulsar at the distance 1.3-3.5 kpc, according to the measurements of the distances of five surrounding pulsars (Taylor at al. 1995, unpublished data). Our distance is less than the estimation as 7.1 kpc derived from HI and OH absorption studies for Kes 79 (Gotthelf at al., 2005). We derive the period of 0.1049122(1) s and the period derivative of 1.1(5)x10^{-13} s/s on JD 2453296.0 using reliable measurements (for 6 days of observations) between JD 2453462 and JD 2453503.

It is the second case of the pulsar discovery in the CCO. The 424 ms X-ray pulsar J1210-5226 in the supernova remnant PKS 1209-51/52 was detected by Zavlin et al. (ApJ 540, L25) in 2000. The radio emission detection is very important, because there is no model for properties of such pulsars and the implications for the origin of CCOs in general. The presence of radio can demonstrate that PSR J1852+0040 is a rotating-powered pulsar (Gotthelf et al. 2005).