2025/04/11 by David Joseph Guevel, Guevel, David, K. L. Page +7
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.2504.08689
openalex publication_date 2025/04/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Extended regions of very high energy γ-ray emission associated with middle-aged pulsars have been found by γ-ray observatories. These regions, called TeV halos or pulsar halos, are thought to be created when energetic electrons from a pulsar or pulsar wind nebula transport into interstellar medium and undergo inverse Compton scattering with the cosmic microwave background radiation. The same electrons are expected to emit synchrotron emission in the X-ray band in the interstellar magnetic field. HESS J1813-126 is a pulsar halo candidate from which TeV γ-ray emission with extension 0.21\degr and a hard E-2 spectrum is observed. We searched for the synchrotron component of this pulsar halo with Swift-XRT. In particular, we observed two fields within the region covered by HESS J1813-126 for 35 ksec each and a region nearby as a background reference for 10 ksec. We find no evidence for excess X-ray emission from the two observations near HESS J1813-126 and place an upper limit differential flux of 4.32× 10-4 \rm keV-1 cm-2 s-1 and 5.38× 10-4 \rm keV-1 cm-2 s-1 at 1 keV assuming an E-2 power law spectrum. The non-detection implies that the magnetic field inside the halo is not significantly enhanced compared to the average Galactic magnetic field.