ROSAT Observations of Pulsed Soft X-Ray Emission from PSR 1055-52
Abstract
Utilizing the position-sensitive proportional counter and the high-resolution imager aboard the orbiting X-ray observatory ROSAT, we have detected pulsations at the radio period from the pulsar PSR 1055-52. The pulse shapes are energy-dependent and show a transition at about 0.5 keV where the phase angle of the pulse peak changes by about -120 deg and the pulsed fraction increases from 11 percent to 63 percent toward larger energies. Simple spectral models are found to be unsatisfactory, while multicomponent models, such as a soft blackbody and hard power-law tail, yield better fits to the pulse-height data. The hard power-law tail is consistent with the extension of the recently reported EGRET results and may indicate a common emission mechanism for the X-ray through GeV gamma-ray regime. The soft blackbody component with T(infinity) = (7.5 +/- 0.6) x 10 exp 5 K, if interpreted as the initial cooling of a neutron star, is consistent with standard cooling models and does not require the presence of exotic components.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1993
- DOI:
- 10.1086/186952
- Bibcode:
- 1993ApJ...413L..31O
- Keywords:
-
- Emission Spectra;
- Pulsars;
- Rosat Mission;
- X Ray Spectra;
- Black Body Radiation;
- Neutron Stars;
- Spectral Energy Distribution;
- X Ray Stars;
- Astrophysics;
- STARS: NEUTRON;
- STARS: PULSARS: INDIVIDUAL ALPHANUMERIC: PSR 1055-52;
- X-RAYS: STARS