Discovery of a spatially extended GeV source in the vicinity of the TeV halo candidate 2HWC J1912+099: a TeV halo or supernova remnant ?

Abstract

Observations by HAWC and Milagro have detected spatially extended TeV sources surrounding middle-aged ($t\sim 100-400\mathrm{kyr}$) pulsars like Geminga and PSR B0656+14, which have been named "TeV Halos", representing very extended TeV pulsar wind nebulae (PWNe) powered by relatively old pulsars. A few more HAWC-detected sources have been suggested to be TeV halo candidates. In this paper, we search for possible GeV counterparts of three TeV halo candidates with Fermi Large Area Telescopes. We detect a new spatially extended GeV source in the vicinity of the TeV halo candidate 2HWC J1912+099, which is also detected by HESS (HESS J1912+101). We find that the size of the GeV source is significantly larger than that of the TeV emission measured by HESS, and a spatial template characteristic of a PWN can fit the GeV data. We suggest that the GeV source is an extended PWN powered by the central middle-aged pulsar PSR J1913+1011. This discovery favors the TeV halo scenario for the TeV source 2HWC J1912+099 (HESS J1912+101), although the possible shell-like morphology measured by HESS challenges this interpretation. Alternatively, the TeV emission could be dominated by a supernova remnant (SNR) via the hadronic process. Future multi-wavelength observations of the source and more precise measurements of the spatial profile of the TeV emission will be useful to distinguish between the two scenarios.

Accepted by ApJ, 7 pages, 6 figures

References in corpus (6)

• Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
• Milagro Observations of Multi-TeV Emission from Galactic Sources in the Fermi Bright Source List
• A radiation transfer model for the Milky-Way: I. Radiation fields and application to High Energy Astrophysics
• Constraining the magnetic field in the TeV halo of Geminga with X-ray Observation
• Search for Pulsar Wind Nebula Associations of Unidentified TeV Gamma-Ray Sources
• Is HESS J1912+101 associated with an old Supernova Remnant?

Cited by in corpus (8)

• Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622 + 3749 Observed by LHAASO-KM2A
• The Physics of Pulsar Halos: Research Progress and Prospect
• TeV cosmic ray nuclei acceleration in shell-type supernova remnants with hard $\gamma$-ray spectra
• Are pulsar halos rare ?
• Galactic Observatory Science with the ASTRI Mini-Array at the Observatorio del Teide
• Features of the gamma-ray pulsar halo HESS J1831$-$098
• Radio and infrared study of the supernova remnant candidate HESS J1912+101
• Hadronic Scenario for Galactic PeVatron LHAASO J1912+1014u Supported by Fermi-LAT $\gamma$-ray Data and FUGIN CO Data