Abstract Details
| Name: ANKAN ROY Affiliation: Indian Institute of Technology Jodhpur Conference ID: ASI2025_443 Title : TeV gamma-rays from photo-disintegration/de-excitation of nuclei in LHAASO J0621+3755 Authors and Co-Authors : Ankan Roy 1, Kritika Yadav 1, Sonali Sahoo 1, Reetanjali Moharana 1 Abstract Type : Poster Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : Very high-energy (VHE) gamma rays are traditionally attributed to two well-known mechanism, purely electromagnetic (EM) synchrotron emission and inverse Compton scattering or hadronic processes such as pion production. They can be also generated through photo-disintegration followed by photo-excitation of daughter nuclei as earlier predicted by Luis A. Anchordoqui and John F. Beacom. This mechanism has been identified as a potential production channel for observed VHE photon events in the Halo J0621 + 3755, associated with the pulsar PSR J0622 + 3749. A unique feature of this process is the production of gamma rays in the energy range of 1 TeV to 100 TeV. Recently, observations from the Large High Altitude Air Shower Observatory (LHAASO) - Kilometres Square Array (KM2A) and the High Altitude Water Cherenkov Observatory (HAWC) have reported photon events in the energy range 10 TeV to 200 TeV and 1 TeV to 10 TeV respectively. With the extended emission of gamma rays from LHAASO J0621 + 3755 Halo, the photon counts follow our model with a spectral index value of 2.32. As the pulsar J0622 + 3749 is a Geminga-like pulsar, assuming the interstellar medium photon temperature akin to the Geminga pulsar, our model's P-value, calculated with best-fit parameter, is greater than 0.43, confirming its validity. Additionally, our analysis demonstrates the model's stability across various nuclei types. This work underscores the importance of photo-disintegration and photo-excitation processes in gamma ray astronomy, offering a novel perspective on VHE gamma ray generation in PWNe and Halos. |