On August 17, 2017, a gravitational-wave event is detected by the LIGO and Virgo interferometers. For the first time, the signal is associated to the merger of two neutron stars. Two seconds after that, a gamma ray burst is detected by the Fermi satellite, inaugurating the multi-messenger astronomy. Many more of these events are expected to be detected in the future. The scientific results from multi-channels analyses will be unprecedented. Multi-messenger astronomy will rely on a network of gravitational-wave interferometers (LIGO-Virgo-KAGRA), on many ground-based and space telescopes, and on high-energy neutrino detectors.
In this context, the SVOM satellite aims at detecting and characterizing gamma ray bursts starting at the end of 2021. On board, the Micro-channel X-ray Telescope (MXT) is designed to localize the burst sources with a precision below 1’ within a few seconds. The LAL group, already involved in gravitational-wave research (LIGO-Virgo), joined the SVOM consortium in 2015. In particular, the LAL group took the responsibility of developing and implementing the on-board localization software for MXT. This work, in collaboration with CEA and CNES teams, also includes an important part focusing on the characterization of the CCD camera of MXT (offset, trigger thresholds, detection of corrupted pixels...), which is also performed on-board. In addition, the telescope optical system is designed and engineered by the English team at Leicester University. The optical characterization is critical for the localization algorithm and the LAL group will contribute to these aspects.
This thesis is a perfect match with the planning of the SVOM mission; it covers both the pre-launch work and the scientific analysis of the first data. Several aspects will be covered, all of them related to the on-board scientific analysis:
- (End 2019) Final developments for the on-board scientific software of MXT. This step will be a good opportunity for the student to get familiar with the software and apprehend the code.
(2019-2022) Software characterization and validation. Tight constraints are set on spatial developments. On top of the system continuous integration, it is planned to use the Panter X-ray facility (Munich) to test the MXT camera, the optical system and the associated software. In this context, the student, in collaboration with the CEA and Leicester teams, will characterize the scientific algorithms and the robustness of the code. Finally, this work will be used to configure the scientific partition.
- (2019-2022) Development of a simulation toolkit for the MXT camera. Over the entire duration of the thesis, the student will have to develop a simulation software to describe the MXT camera. This tool will be able to realistically simulate the camera and electronic noise. On top of it, one must simulate the camera response to external sources (high-energy photons, cosmic rays...).
(2019-2021) Tests and scientific validation of the simulation toolkit, using the gamma ray bursts catalog from the SWIFT XRT telescope (equivalent to SVOM/MXT). Extrapolation to SVOM/MXT: detection rate estimation and characterization of the gamma ray bursts for SVOM/MXT.
- (2021-2022) Analysis of the first data collected by SVOM/MXT. The PhD student will have access to about 6 months of real data, including a few dozens of gamma ray burst events. This very important step will give the opportunity to validate all the work described above: validation of the simulation toolkit, of the camera behavior and the associated software. This work will eventually provide the final configuration of the scientific algorithm of MXT. Finally, the PhD student will evolve in the Virgo/SVOM group at LAL, a privileged environment to deal with multi-messenger astronomy
Interested in multi-messenger astronomy. Knowledge in astro-particules. M2 astronomy/astronphysics or spatial technics will be preferred.
To apply, we invite you to contact the PhD/research supervisor and fill, with him/her, the co-financing part of the online application form (Reply to the offer) by April 1st, 2019.