SearcharxivSearch

arXiv subjects

Beatrice Crudele

Publications and source records attributed to Beatrice Crudele.

2 recordsLinked to original sources

Neutrinos as a new tool to characterise the Milky Way Centre

The Central Molecular Zone (CMZ), a star-forming region rich in molecular clouds located within hundreds of parsecs from the centre of our Galaxy, converts gas into stars less efficiently than anticipated. A key challenge in refining star-formation models is the lack of precise mapping of these dense molecular hydrogen clouds, where traditional tracers often yield inconsistent results. We demonstrate how, in the near future, neutrinos will emerge as a robust mass tracer due to worldwide advancements in neutrino telescopes. Neutrinos are produced alongside gamma-rays when cosmic-rays interact with molecular clouds. The neutrino production rate is proportional to the gas density without dependence on the complex properties of a cloud. Neutrinos also have the advantage of negligible absorption and unambiguous production channels, making it a method with the lowest systematic uncertainties. In an optimistic case where most gamma-ray emission from the Galactic Centre region originates from pion decays, we expect several tens of muon neutrinos to be detected in about two decades. Neutrinos from the CMZ will provide indications on the biases of traditional mass tracers and thus indirectly enhance the accuracy of gas measurements in far galaxies from which a neutrino signal is not detectable.

astro-ph.HE

Neutrino Imaging of the Galactic Centre and Millisecond Pulsar Population

In this work, we consider the possible presence of a large population of millisecond pulsars in the Galactic Centre. Their direct detection would be challenging due to severe pulse broadening caused by scattering of radiation. We propose a new method to constrain their population with neutrino imaging of the Galactic Centre. Millisecond pulsars are proposed cosmic-ray accelerators. The high-energy protons they produce will collide with the baryonic matter in the central molecular zone to create charged and neutral pions that decay into neutrinos and $γ$-rays, respectively. The specific neutrino and $γ$-ray fluxes must be below their corresponding observed values, allowing us to put a conservative upper limit on the millisecond pulsar population of N_MSP < 10,000 within a galacto-centric radius of 20 pc. This upper limit is sensitive to the proton acceleration efficiency of the pulsars, but is less dependent on the particle injection spectral index and the choice of mass tracers. The population will be better constrained when high resolution neutrino observations of the Galactic Centre become available. The presence of these millisecond pulsars can account for the $γ$-ray excess in the Galactic Centre.

astro-ph.HE