VLA/realfast detection of pulsed emission from PSR J1745-2900
ATel #13042; Casey Law (Caltech) and Robert Wharton (MPIfR) on behalf of the realfast and 19A-397 collaborations
on 21 Aug 2019; 15:47 UT
Credential Certification: Casey Law (claw@astro.caltech.edu)
Subjects: Radio, Magnetar
We report the detection of radio pulses from the Galactic Center magnetar PSR J1745-2900 (Eatough 2013; ATEL #5040, #5058, #5076) with the Very Large Array (VLA) and the realfast commensal transient search system (Law et al 2018). The realfast commensal transient search system currently runs by default on VLA continuum observations at frequencies from 1 to 4 GHz (see http://realfast.io ).
On August 20 at 01:30UT, a VLA observing program (19A-397; PI Wharton) targeted multiple fields within a few arcminutes of the Galactic center. This program observed in the 2-4 GHz frequency band with the realfast system searching visibilities sampled at a 10 ms cadence. The fast transient search pipeline dedispersed visibilities from 0-2000 pc/cm3, imaged each integration, and searched images for new radio sources in real time.
The search pipeline found dozens of individual pulses with a dispersion measure of roughly 1750 pc/cm3 at RA = 17:45:40, Dec = -29:00:30 (J2000), which is consistent values measured for PSR J1745-2900. The first pulse was detected with a topocentric MJD of 58715.05771 at 4 GHz. Dozens of pulses were detected over the subsequent three hours of observing with significance ranging from 10 to 30 sigma (approximately 50 to 150 mJy in 10 ms). We estimate a burst detection rate of one every few minutes above a limiting flux density of approximately 50 mJy in 10 ms.
