The origin of very- and ultra-high-energy cosmic rays remains one fundamental question in astroparticle physics. High-energy neutrinos would provide a distinct signature for acceleration processes in galactic and extragalactic sources. Though some of these sources may be opaque to gamma rays, they may emit in the X-ray range, producing a clear correlation between X-ray and neutrino emission. Examples of such sources include microquasars, binary systems composed of a stellar-mass black hole and a companion star, observed within the Milky Way, and active galactic nuclei (AGN), a central engine related to a supermassive black hole in the centre of a galaxy. The KM3NeT telescope, located in the depths of the Mediterranean Sea, offers a unique view of the Galactic Plane and the extragalactic sky in neutrinos and is therefore well-suited to identify such sources.
This PhD project aims to conduct a joint analysis of KM3NeT data with X-ray data from the SVOM and Einstein Probe missions. The latter may extend from transient signals detected in X-rays to light curves, outcomes of the monitoring of interesting sources, such as galactic microquasars, over a longer period of time. The detection of temporal and spatial correlations between neutrino and X-ray signals would provide an unprecedented proof of the existence of hadronic acceleration processes within the identified sources. The PhD candidate will have the opportunity to develop analysis methods both within the KM3NeT framework and eventually through open-source tools initially developed by the electromagnetic community.
The project will be conducted within the APC laboratory (Astroparticle and Cosmology Laboratory, Paris), an active member of KM3NeT, SVOM, and Einstein Probe. The team has recognized expertise in multi-messenger astrophysics, neutrino data analysis, gamma-ray and X-ray observations, and phenomenological modeling of astrophysical sources, notably AGN, in close connection with renowned experts at APC. This environment will enable the implementation of a multi-messenger approach to correlate neutrino observations with X-ray data, and eventually gamma rays, providing strong constraints on emission mechanisms.
The student will be part of both the SVOM, Einstein Probe and KM3NeT collaborations. We therefore expect them to participate in collaboration meetings (travelling 3-4 times per year) and take part in the data processing, detector monitoring, and maintenance activities. Additionally, some experience with Python programming (optionally also C++) and with data analysis would be highly appreciated. Whenever possible, we strongly encourage candidates to also join us in advance for a master's project on a similar topic.