【11.26; Seminar】2025年粒子天体物理全国重点实验室系列学术报告 #33：Probing high energy sky with LHAASO

时间/Time: 11月26日周三下午2:00/Wednesday, November 26, 2:00 p.m.

地点/Location: online zoom: 96886381553（password:123456）

报告人/Speaker: Sushmita Agarwal（Tata Institute of Fundamental Research, Mumbai, India）

题目/Title: Probing high energy sky with LHAASO

主持人/Host: 李哲/Zhe Li

摘要/Abstract:

Blazars are among the most efficient natural particle accelerators, capable of producing gamma-ray photons up to the TeV–PeV regime through extreme leptonic or hadronic processes. Despite their importance, only a small fraction have been confirmed in the very-high-energy (VHE; >100 GeV) band due to limited observational windows, instrument sensitivity, and attenuation by the extragalactic background light (EBL). VHE gamma-ray emission from blazars also serves as a tracer of hadronic acceleration, offering indirect evidence for sites capable of producing ultra-high-energy cosmic rays and neutrinos.

Using 16 years of Fermi-LAT observations (0.1–2 TeV), we identify 92 new VHE-emitting HSP blazars at ≥5σ significance and confirm 52 previously known VHE sources. Several candidates display hard intrinsic gamma-ray spectra, >500 GeV photon detections, and photon arrivals during both flaring and quiescent states, indicating persistent particle acceleration in jets. I will discuss the spectral, temporal, population characteristics of these sources, assess their feasibility for follow-up with current Cherenkov telescopes under EBL attenuation, and provide a prioritized target list optimized for LHAASO. This study delivers a statistically robust roadmap for VHE blazar observations, enabling strong synergy with upcoming wide-field, high-sensitivity gamma-ray facilities and multi-messenger programs.

个人简介/Biography:

Sushmita Agarwal is a postdoctoral fellow at the Tata Institute of Fundamental Research, Mumbai, India, currently working on understanding extreme particle accelerators hosted in relativistic jets powered by supermassive black holes. She recently led a systematic survey identifying new very-high-energy (VHE) emitting HSP blazar candidates and developed a prioritized source list for next-generation facilities such as LHAASO and CTAO. Her broader research interests include hunting extreme cosmic accelerators and conducting systematic studies to probe particle acceleration mechanisms and their potential multi-messenger connections.