Investigation of the Properties of a Pulsar in Close Proximity by Astronomers

Using the XMM-Newton satellite and the Hubble Space Telescope (HST), astronomers have made X-ray and near-infrared observations of a nearby, middle-aged pulsar known as PSR B1055-52. Monitoring campaign results published on arXiv Preprint server, providing basic information regarding the properties of this pulsar.

Pulsars are highly magnetized neutron stars that spin around and emit a beam of electromagnetic radiation. They are usually detected in short bursts of radio emission; However, some of them have also been observed via optical, X-ray, and gamma-ray telescopes.

Although the distance to PSR B1055–52 remains uncertain, previous studies indicate that it is no more than 2,300 light-years from Earth. PSR B1055-52 has a spin period of 197 ms, a spin age of about 535,000 years, a downward spin force of 30 decillion erg/s, and a surface magnetic field of 1.1 TG.

PSR B1055–52 is a well-studied pulsar, but there are some discrepancies regarding its X-ray spectral and flux parameters. For this reason, a group of astronomers led by Bettina Bosselt of the University of Oxford, UK, decided to investigate PSR B1055-52 using XMM-Newton and HST.

Previous observations of gamma-ray, X-ray, and middle-aged radio pulsars indicated some characteristics, such as a suspected change in X-ray flux and spectral parameters, and a significant increase in the alleged thermal component of the ultraviolet (UV) spectrum over the Rayleigh-Jeans extension of the thermal spectrum of radiation. X-rays, a possible double fracture in the non-thermal spectral component between the X-ray and photonic bands. We observed PSR B1055-52 with the XMM-Newton X-ray Observatory and the Hubble Space Telescope in near infrared.”

The study found that the long-term X-ray properties of PSR B1005-52 appeared to be stable based on a comparison between the 2000 observations and the new XMM-Newton conducted in 2019. Furthermore, the probability of short-term X-ray flux changes that occurred before or around 2012 can not be completely ruled out. The astronomers hypothesize that a calibration problem with the 2012 Chandra observation may explain discrepancies reported by previous studies.

The power law spectrum index of PSR B1005-52 was measured to be 0.57 in the 3–10 keV energy range, and the power law slope was calculated to be about 0.24 for the 0.03 mag color index. It is observed that the power law components of the UV, optical and X-ray spectra have similar slopes and relate to each other smoothly, suggesting common acceleration and emission mechanisms.

Furthermore, the X-ray spectrum of PSR B1005-52 is inconsistent with model spectra of the neutron star’s atmosphere, similar to other middle-aged pulsars. This may indicate a condensed neutron star surface, whose spectrum is perhaps closer to that of a black body.

The new observations also allowed the researchers to accurately measure the proper motion of PSR B1005-52, which may be necessary to estimate the motional age of this pulsar.

In principle, the now known proper motion could be used to constrain the kinetic age, providing an independent estimate of the age in preference to the somewhat uncertain characteristic age. This information allows for a more reliable comparison with other NS (neutron stars) as well as with theoretical predictions. , such as the NS cooling curves”.

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