Abstract

Vela Pulsar (PSR B0833-45/PSR J0835-4510) is one of the most active pulsars in terms of glitching, counting 20 in the last 50 years. The latest glitch occurred recently, around MJD 58515, an was reported in ATEL #12466. Here we report on radio timing observations performed at IAR, Argentina, confirming such a glitch and estimating the jump of the period, and the following slow-down rate. 

The IAR (Argentinian Institute of Radio Astronomy) is going through major upgrades to suit its two 30-m antennas (A1, A2) for pulsar timing investigations. The observations reported here are single-polarization, with a bandwidth of 56 MHz, centered at 1400 MHz. Both technical upgrades and observations are performed by the PuMA Collaboration (Pulsar Monitoring in Argentina). 

As part of the commissioning and developing stage, regular observations of Vela PSR with both antennas were restarted by the end of January after ~1 month of inactivity. We observed Vela PSR on Jan 29 (MJD 58512.14) with P_bary = 89.402260(7) ms, consistent with the available ephemeris before the glitch. After the glitch was reported (ATEL #12466), we started a daily follow-up, observing on Feb. 04 (MJD 58518.15), Feb. 05 (MJD 58519.10), Feb. 06 (MJD 58520.10) and Feb. 07 (MJD 58521.10). In our first post-glitch observation in MJD 58518.15, we obtained a period P_bary = 89.402074(8) ms, showing a decrease Delta P = -0.18(1) us with respect to MJD 58512.14. Later consecutive observations show that the period is recovering with a rate Pdot / P = 1.66(3) e-12 s^{-1} (see Figure 1). With this data we estimate the magnitude of the jump during the glitch to be Delta P ~ -0.25 us (consistent with the value recently estimated in ATel #12481). 

We will continue performing daily monitoring of Vela PSR at 1.4 GHz during the glitch recovery phase.