Using the XMM-Newton, Chandra and NuSTAR space telescopes, an international team of astronomers investigated the nature of a newly discovered very high-energy source called 2FHL J1745.1–3035. Research results published on the previous server on January 24 arXiv He suggested that the source might be a pulsar wind nebula.

The second Fermi-LAT High Energy Source Catalog (2FHL) presents the locations, spectra, and variability characteristics of 360 sources discovered by NASA’s Fermi mission, largely in the 50 GeV–2 TeV energy range. It contains 12 very high energy (VHE) sources in the galactic plane with a gamma-ray photon index below 1.8 that are currently unconnected.

One such unrelated VHE source is 2FHL J1745.1–3035, located near the Galactic center. In gamma-ray emission, this source is the second brightest among the uncorrelated VHE sources in the 2FHL sample. Previous observations had shown that 2FHL J1745.1–3035 has a hard gamma-ray spectrum above 50 GeV and is a TeV emitter.

To shed further light on the properties and nature of 2FHL J1745.1–3035, a team of astronomers led by Stefano Marchesi of the University of Bologna in Italy also analyzed new archival data from NASA’s Chandra and NuSTAR spacecraft. Like from ESA’s XMM-Newton satellite.

“We present a multi-observatory, multi-period X-ray analysis of 2FHL J1745.1-3035, a recently discovered very high-energy galactic source detected by the Large Fermi Telescope (LAT) in the immediate vicinity of the galactic center.” researchers explained.

Analyzing the X-ray and gamma-ray properties of 2FHL J1745.1-3035, astronomers found that the X-ray source is compact and shows no evidence of expansion. But Chandra’s observations allowed the researchers to detect significantly extended emission down to about 5 arcseconds.

A study of the spectral properties of 2FHL J1745.1-3035 shows that the source is very hard at energies below 10 keV and much softer in the higher energy range. According to the study, the broadband X-ray spectrum of the source best fits a distorted power law model, with a burst energy of about 7 keV.

The authors of the paper concluded that the results of the study suggest that 2FHL J1745.1–3035 is most likely a powerful pulsar wind nebula (PWN). In general, PWNe are nebulae fed by the pulsar wind. The pulsar wind consists of charged particles and develops a PWN when it collides with the pulsar’s environment, particularly the slowly expanding supernova ejecta.

If the PWN scenario for 2FHL J1745.1–3035 is confirmed by further studies, it would be one of the most complex PWNe ever detected in X-rays and one of the most difficult PWNe ever detected in gamma rays.