# X-ray studies of the gamma-ray pulsar J1826-1256 and its pulsar wind nebula with Chandra and XMM-Newton

## TL;DR

This study analyzes X-ray data from Chandra and XMM-Newton to investigate the spectral properties, nebula structure, and potential associations of the gamma-ray pulsar J1826-1256, revealing synchrotron cooling and estimating its distance.

## Contribution

It provides the first detailed spectral and morphological analysis of pulsar J1826-1256 and its nebula using archival X-ray data, and discusses its possible astrophysical associations.

## Key findings

- Pulsar spectrum fits a power-law with photon index ~1.
- Nebular spectrum softens with distance, indicating synchrotron cooling.
- Estimated distance to pulsar is approximately 3.5 kpc.

## Abstract

We have analyzed archival XMM-Newton and Chandra observations of the gamma-ray radio-quiet pulsar J1826-1256 and its pulsar wind nebula. The pulsar spectrum can be described by a power-law model with a photon index $\Gamma\approx1$. We find that the nebular spectrum softens with increasing distance from the pulsar, implying synchrotron cooling. The empirical interstellar absorption-distance relation gives a distance of $\approx3.5$ kpc to J1826-1256. We also discuss the nebula geometry and association between the pulsar, the very high energy source HESS J1826-130, the supernova remnant candidate G18.45-0.42 and the open star cluster Bica 3.