Discovery of X-Rays from the Old and Faint Pulsar J1154-6250
Abstract
We report on the first X-ray observation of the 0.28 s isolated radio pulsar PSR J1154-6250 obtained with the XMM-Newton observatory in 2018 February. A point-like source is firmly detected at a position consistent with that of PSR J1154-6250. The two closest stars are outside the 3σ confidence limits of the source position and thus unlikely to be responsible for the observed X-ray emission. The energy spectrum of the source can be fitted equally well either with an absorbed power law with a steep photon index Γ ≈ 3.3 or with an absorbed blackbody with temperature kT = 0.21 ± 0.04 keV and emitting radius R BB ≈ 80 m (assuming a distance of 1.36 kpc). The X-ray luminosity of 4.4 × 1030 erg s-1 derived with the power-law fit corresponds to an efficiency of {η }X={L}Xunabs}/\dot{E}=4.5× {10}-3, similar to those of other old pulsars. The X-ray properties of PSR J1154-6250 are consistent with an old age and suggest that the spatial coincidence of this pulsar with the OB association Cru OB1 is due to a chance alignment.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2018
- DOI:
- 10.3847/1538-4357/aadd93
- arXiv:
- arXiv:1809.00011
- Bibcode:
- 2018ApJ...865..116I
- Keywords:
-
- methods: observational;
- pulsars: individual: J1154–6250;
- stars: neutron;
- X-rays: stars;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in the ApJ on 27th of August