3rd Year PhD Student Presentations

Europe/Paris
    • 1
      Study of the hadronic PeVatron candidate SNR G106.3+2.7 observed at Large Zenith Angle with LST-1 and MAGIC

      Abstract: The quest for PeVatrons, sources of Galactic cosmic rays accelerated up to PeV energies, lived an exciting development with the recent discoveries from the LHAASO Collaboration. Published in 2023, the first LHAASO catalog of Gamma-Ray sources presents 43 sources of ultra-high energy emissions (UHE, E > 100 TeV). Among them, a promising hadronic PeVatron candidate is the supernova remnant SNR G106.3+2.7, for which the ultra-high energy emission has been interpreted using both hadronic and leptonic scenarios.

      Imaging Atmospheric Cherenkov Telescopes (IACTs) are ideal instruments to investigate the nature of extended sources in the gamma-ray domain thanks to their better angular and energy resolution compared to UHE detectors. Using the LST-1, the first Large-Sized Telescope of the Cherenkov Telescope Array Observatory, together with the two neighboring MAGIC IACTs, we are currently observing the SNR G106.3+2.7 at Large Zenith Angle (LZA, zenith = 55°-75°), which allows us to explore the 1-50 TeV energy range.

      Such observations raise challenges regarding the data reconstruction and analysis, due to the zenith angle dependency of the Random Forest-based reconstruction and of the telescope acceptance. In this presentation, I will present the work we did to overcome these challenges and show preliminary results, including a first morphological and spectral analysis of the source.

      Orateurs: Marie sophie CARRASCO (Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France), Marie-Sophie Carrasco (Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France)
    • 2
      Design and Testing of a Readout Chip with Integrated Sensor for High Energy Physics [by zoom]

      Abstract: The Belle II experiment collects data from the SuperKEKB accelerator with an instantaneous luminosity of up to 6e35 cm-2.s-1. Achieving such high luminosities creates challenges for the vertex detector due to a large and continuous rate of background particles. To address this, a new detector is proposed, which aims to improve space and time granularity by using a depleted monolithic pixel sensor called OBELIX (Optimized BELLeII pIXel).
      Based on the existing TJ-Monopix2 chip initially developed for the ATLAS Inner Tracker (ITk) upgrade (LHC, CERN, Geneva), OBELIX is designed in a 180 nm CMOS process with an improved pixel matrix and additional functionalities such as new on-chip voltage regulators.
      The talk will review the overall design of the OBELIX sensor with the focus on analog part.

      Orateur: Roua Boudagga (CPPM, Aix Marseille Université, CNRS/IN2P3, Marseille, France)
    • 3
      Modeling the instrumental response of a space telescope

      Abstract: While astronomical images reveal increasing levels of detail and instruments reach complexity levels never seen before, the need for accurate and efficient data analysis is more pressing and challenging than ever.
      The DISPERS project aims at leveraging cutting-edge machine learning techniques to generate slitless spectroscopy images, addressing key challenges as PSF estimation and overall instrumental response modeling. As accurate PSF modeling allows us to characterize the optical aberrations inherent to systems like Euclid's Near Infrared Spectrometer and Photometer (NISP), our understanding significantly improves the precision of galaxy redshift measurements and enables high-fidelity dark matter/energy mapping.
      This seminar will focus on Spread, an innovative ML framework developed to predict optical aberrations from PSFs. By establishing this correlation, Spread provides a new approach allowing WFE analysis without the need for WaveFront sensor implementation.

      Orateur: Lucas Sauniere (CPPM, Aix-Marseille Université, CNES, CNRS/IN2P3 (FR))