AstroparticlePhysics
Menu
Lake Baikal, home of the Baikal neutrino telescope

Research area

Neutrino astronomy

Neutrinos point back to otherwise hidden cosmic accelerators. Searches with ANTARES, IceCube and gamma-ray observatories help trace their astrophysical origins.

Neutrinos point back to cosmic accelerators that may be hidden at other wavelengths. I have been a member of the ANTARES collaboration, which operated a neutrino telescope in the Mediterranean Sea, since 2009, and I combine neutrino data with gamma-ray observations to search for their sources, from ANTARES sky maps to real-time follow-up of IceCube alerts.

ANTARES · 2010–2014

Searching for clusters in the neutrino sky

In 2010 I obtained a three-year Marie Curie fellowship through the COFUND action "EuroTalents" for a research project on searches for sources of astrophysical neutrinos with ANTARES. Its main result is an improved method to search for clusters in sky maps, based on the auto-correlation of individual events. Applied to the ANTARES high-energy neutrino data, together with cross-correlations with other messengers and source candidates (high-energy gamma-ray sources, massive black holes and nearby galaxies), it found no significant deviation from the isotropic distribution expected from atmospheric backgrounds.

ANTARES · TAToO

Neutrino alerts for telescopes

Within the TAToO sub-collaboration I helped develop and commission an online alert system that connects ANTARES to networks of robotic optical telescopes, the Swift X-ray satellite and the H.E.S.S. gamma-ray observatory. A fast online reconstruction of muon tracks triggers the follow-up for special events, such as two or more neutrinos coincident in time and direction, or a single neutrino of very high energy.

Real-time multi-messenger alerts

IceCube · H.E.S.S. and partners

Real-time follow-up of IceCube neutrinos

Since the neutrino IceCube-170922A pointed to the flaring blazar TXS 0506+056, the Cherenkov telescopes FACT, H.E.S.S., MAGIC and VERITAS have been following IceCube alerts: single astrophysical neutrino candidates, and known gamma-ray sources after IceCube identifies a cluster of neutrino events. I led, on behalf of H.E.S.S., the joint analysis of these programmes from September 2017 to January 2021, combined with Fermi-LAT and IceCube into one legacy data set.

Individual alerts can trigger large campaigns. The blazar PKS 0735+178, 2.2° from the neutrino IceCube-211208A, was in a high state from the optical to GeV gamma rays at the time of the neutrino; the gamma-ray data from Fermi-LAT, VERITAS and H.E.S.S. require a spectral cutoff near 100 GeV, which strongly constrains both leptonic and hadronic models.

A global neutrino hunt TXS 0506+056

Sky map in equatorial coordinates of IceCube neutrino alerts from 2017 to 2021, with those followed up by the Cherenkov telescopes in colour

ANTARES · since 2009

Inside the collaboration

I developed an energy reconstruction algorithm and a data format for physics analysis that became the standard within ANTARES. In 2010 I was appointed convener of the working group "Analysis Tools: Software and Reconstruction" and thereby became a member of the ANTARES Steering Committee. I have also served as internal referee for several physics papers and was a nominated member of the Publication Board from 2012 to 2016.

SGSO + AMIGO: a second life for ANTARES modules

Related news · Neutrino astronomy

From the news.