8 MARZO 2022 ore 15:00

Dissecting the gamma-ray Galactic Center Excess

Dr. Silvia Manconi (RWTH University in Aachen, Germania)
Dissecting the gamma-ray Galactic Center Excess

Didascalia immagine: Count distribution of sources as a function of gamma-ray
flux S (ie dN/dS) in the inner Galaxy. Points: dN/dS of sources in the fourth Fermi-LAT catalog. Lines: dN/dS as measured by pixel count statistics (1pPDF) adopting
interstellar background emission models optimized with adaptive template fitting (SF-). This permits to robustly measure the dN/dS about one order of magnitude below the catalog threshold.


Abstract: The Galactic center excess (GCE) is an unexpected gamma-ray component over astrophysical background detected at GeV energies towards the Galactic Center by the Fermi-Large Area Telescope (LAT).
Intriguingly, the GCE could be hinting at Weakly Interacting Massive Particles annihilating in the Galactic dark matter halo. Moreover, it could also be due to a population of millisecond pulsar-like sources emitting below the threshold of current Fermi-LAT catalogs. In order to disentangle between different interpretations, a detailed analysis of its morphology and spectral characteristics should deal with the
systematic uncertainties coming from the interstellar background emission, which dominate the observed photons. A plethora of techniques has been recently used to further investigate the GCE, ranging from template fitting, photon-count statistics to machine learning.
In this talk I will review our current understanding of the GCE, illustrating both technical developments as well as their consequences for the interpretation of the excess. I will focus on recent efforts to minimize the mismodeling coming from the interstellar background emission, by combining for the first time [1] adaptive template fitting and pixel count statistics in order to robustly assess the role of
sub-threshold point sources.

[1] Calore, Donato, Manconi, Phys. Rev. Lett. 127, 161102 2021



Breve CV della Dr. Silvia Manconi:

La Dr. Silvia Manconi é nata e cresciuta in Sardegna. Ha ricevuto la sua Laurea Triennale in Fisica all'Universitá di Cagliari nel 2012. Quindi si é trasferita a Torino, dove ha prima ottenuto la Laurea Magistrale nel 2015 e poi il Dottorato di Ricerca in Fisica ed Astrofisica nel 2019. La tesi di dottorato di Silvia é stata premiata nel 2019 con il Premio Fubini dall'INFN per la miglior tesi in fisica teorica discussa in Italia.  Da ottobre 2019, é una ricercatrice post-dottorato all'Institute for Theoretical Particle Physics and Cosmology (TTK) at the RWTH University in Aachen (Germany).
La ricerca di Silvia é focalizzata su diversi aspetti della teoria della fisica delle particelle, che va dalla ricerca di segnali della materia oscura nei raggi cosmici e nei raggi gammi allo studio degli accelleratori di raggi cosmici Galattici ed extragalattici con tecniche multi frequenza.