Timing irregularities of PSR~J1705$-$1906

TL;DR

This study analyzes over fourteen years of timing data from PSR J1705-1906, revealing its proper motion, rotation irregularities, and two small glitches, while employing advanced noise analysis techniques.

Contribution

It provides the first power spectrum analysis of timing noise for PSR J1705-1906 and refines its astrometric and rotational parameters using long-term observational data.

Findings

Proper motion measured as -77(3) mas/yr in RA and -38(29) mas/yr in Dec.

Detected two small glitches with fractional frequency jumps of ~2.9×10^{-10} and ~2.7×10^{-10}.

Power spectrum analysis shows a spectral exponent of -5.2, indicating dominant red noise in spin fluctuations.

Abstract

Timing analysis of PSR J1705$-$1906 using data from Nanshan 25-m and Parkes 64-m radio telescopes, which span over fourteen years, shows that the pulsar exhibits significant proper motion, and rotation instability. We updated the astrometry parameters and the spin parameters of the pulsar. In order to minimize the effect of timing irregularities on measuring its position, we employ the Cholesky method to analyse the timing noise. We obtain the proper motion of $-$77(3) \,mas\,yr$^{-1}$ in right ascension and $-$38(29) \,mas\,yr$^{-1}$ in declination. The power spectrum of timing noise is analyzed for the first time, which gives the spectral exponent $\alpha=-5.2$ for the power-law model indicating that the fluctuations in spin frequency and spin-down rate dominate the red noise. We detect two small glitches from this pulsar with fractional jump in spin frequency of $\Delta \nu/\nu\sim2.9\times10^{-10}$ around MJD~55199 and $\Delta \nu/\nu\sim2.7\times10^{-10}$ around MJD~55953. Investigations of pulse profile at different time segments suggest no significant changes in the pulse profiles around the two glitches.