Ponente
Descripción
The recent catalog published by the Large High Altitude Air Shower Observatory (LHAASO) Collaboration unveiled many new unidentified sources at Very-High-Energies (VHEs, E>50 GeV) and Ultra-High-Energies (UHEs, E>100 TeV), many of which lie near pulsars, reinforcing the hypothesis of pulsars as some of the most powerful accelerators in the universe. Among these, 1LHAASO J1740+0948u stands out with its spectrum extending beyond 300 TeV. The closest pulsar is PSR J1740+1000, a middle-aged source powering a cometary bow shock Pulsar Wind Nebula (PWN) and located at 20° above the Galactic plane. The lack of other nearby counterparts supports the connection between the two sources. Two main scenarios could explain the origin of the VHE emission: either 1LHAASO J1740+0948u represents the VHE detection of the tail PWN or it could be due to an extended pulsar halo around PSR J1740+1000
Multiwavelength studies are crucial in providing constraints on the parameters of the systems. In particular, X-ray observations are particularly important to constrain the Spectral Energy Distribution (SED) and provide key insight into the system's magnetic field.
During this talk I will present the results of an in-depth analysis based on more than 500 ks of XMM-Newton observations centred on PSR J1740+1000, aimed at investigating the origin of 1LHAASO J1740+0948u. We performed for the first time a deep search for diffuse non thermal X-ray emission, both around the pulsar and close to the location of the LHAASO source, and derived stringent 3σ upper limits on their fluxes. We also revisited the PWN spectrum and found no evidence for synchrotron cooling. Finally, I will present the results of the multiwavelength SED modelling, through which we tested the two proposed scenarios on the origin of the VHE emission and obtained new estimates on the magnetic field both in the PWN and in the diffuse non-thermal X-ray emission.
