Abstract
We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17stat±0.02sys. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.
Recommended Citation
"Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed By LHAASO-KM2A," Physical Review Letters, vol. 126, no. 24, article no. 241103, American Physical Society, Jun 2021.
The definitive version is available at https://doi.org/10.1103/PhysRevLett.126.241103
Department(s)
Physics
International Standard Serial Number (ISSN)
1079-7114; 0031-9007
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 American Physical Society, All rights reserved.
Publication Date
18 Jun 2021
PubMed ID
34213924
Comments
National Natural Science Foundation of China, Grant RTA6280002