Discovery of the anti-glitch in PSR J1835$-$1106

TL;DR

This paper reports the first detection of an anti-glitch in the pulsar PSR J1835-1106, analyzing its properties and discussing possible internal and external mechanisms behind this rare event.

Contribution

It presents the discovery of an anti-glitch in PSR J1835-1106 and evaluates different models, favoring the wind braking scenario over superfluid models.

Findings

Detected an anti-glitch with fractional frequency change of -3.46e-9.

No significant pulse profile changes before and after the event.

Wind braking scenario explains the anti-glitch better than superfluid models.

Abstract

We report the detection of an anti-glitch with a fractional frequency change of $\Delta\nu/\nu=-3.46(6)\times10^{-9}$ in the rotation-powered pulsar PSR J1835$-$1106 at MJD 55813, based on timing observations collected with the Nanshan 26-m and Parkes 64-m radio telescopes from January 2000 to July 2022. A comparison of the average pulse profiles within $\pm300$ d of the event reveals no significant morphological changes. We also estimate the angular velocity lag between the normal and superfluid components at the time of the glitch, showing that one of the superfluid glitch models is incompatible with PSR J1835$-$1106 due to its insufficient spin-down rate and angular velocity lag. The wind braking scenario offers a viable alternative, consistent with the observed spin-down behavior, glitch amplitude, and post-glitch recovery. High-cadence, high-sensitivity monitoring of similar events is essential to distinguish between internal (superfluid) and external (wind-related) glitch mechanisms.