# The Green Bank North Celestial Cap Pulsar Survey. IV: Four New Timing Solutions

## TL;DR

This paper reports four new pulsar timing solutions from the GBNCC survey, highlighting an unusual low spin-down rate in one pulsar that may suggest unique evolutionary history, and provides insights into their distances and luminosities.

## Contribution

The study presents four newly discovered pulsar timing solutions, including detailed analysis of PSR J0038-2501's low spin-down rate and potential evolutionary implications.

## Key findings

- PSR J0038-2501 has an unusually low period derivative.
- PSR J1949+3426 is among the most distant and luminous pulsars.
- No X-ray emission detected from PSR J0038-2501, ruling out a young CCO.

## Abstract

We present timing solutions for four pulsars discovered in the Green Bank Northern Celestial Cap (GBNCC) survey. All four pulsars are isolated with spin periods between 0.26$\,$s and 1.84$\,$s. PSR J0038$-$2501 has a 0.26$\,$s period and a period derivative of ${7.6} \times {10}^{-19}\,{\rm s\,s}^{-1}$, which is unusually low for isolated pulsars with similar periods. This low period derivative may be simply an extreme value for an isolated pulsar or it could indicate an unusual evolution path for PSR J0038$-$2501, such as a disrupted recycled pulsar (DRP) from a binary system or an orphaned central compact object (CCO). Correcting the observed spin-down rate for the Shklovskii effect suggests that this pulsar may have an unusually low space velocity, which is consistent with expectations for DRPs. There is no X-ray emission detected from PSR J0038$-$2501 in an archival swift observation, which suggests that it is not a young orphaned CCO. The high dispersion measure of PSR J1949+3426 suggests a distance of 12.3$\,$kpc. This distance indicates that PSR J1949+3426 is among the most distant 7% of Galactic field pulsars, and is one of the most luminous pulsars.