X-Ray and Near-Infrared Observations of the Middle-aged Pulsar B1055-52, Its Multiwavelength Spectrum, and Proper Motion
Abstract
Previous observations of the middle-aged γ-ray, X-ray, and radio pulsar B1055-52 indicated some peculiarities, such as a suspected changing of the X-ray flux and spectral parameters, a large excess of the alleged thermal component of the UV spectrum over the Rayleigh-Jeans extension of the X-ray thermal spectrum, and a possible double break in the nonthermal spectral component between the optical and X-ray bands. We observed PSR B1055-52 with the XMM-Newton observatory in X-rays and the Hubble Space Telescope in near-infrared (NIR). The analysis of the XMM-Newton observations does not support the notion of long-term changes in the X-ray flux and broadband X-ray spectrum of the pulsar. Using an observing mode less affected by background noise than the previous XMM-Newton observations, we constrain the power-law (PL) spectral index as ${\alpha }_{X}=-{0.57}_{-0.25}^{+0.26}$ (F ν ∝ ν α ) in the energy band 3-10 keV. From the NIR-optical data we obtain a PL slope α O = -0.24 ± 0.10 for the color index E(B - V) = 0.03 mag. The slopes and fluxes of the NIR-optical and X-ray nonthermal spectra suggest that the NIR through X-ray emission can be described by the same PL and is generated by the same mechanism, unlike the pulsar's γ-ray emission. The excess of the UV thermal component over the extension of the X-ray thermal component became smaller but did not disappear, indicating a nonuniformity of the bulk surface temperature. The NIR data also enable us to measure the proper motion accurately, with values μ α = 47.5 ± 0.7 mas yr-1 and μ δ = -8.7 ± 0.7 mas yr-1. * Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. Based also on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #15676.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2023
- DOI:
- 10.3847/1538-4357/acd9d1
- arXiv:
- arXiv:2306.00185
- Bibcode:
- 2023ApJ...952..134P
- Keywords:
-
- Pulsars;
- Neutron stars;
- 1306;
- 1108;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- ApJ accepted