Astrophysical constraints on a possible neutrino ball at the Galactic Center

Abstract

The nature of the massive object at the Galactic Center (Sgr A${}^{\ast }$) is still unclear even if various observational campaigns led many authors to believe that our Galaxy hosts a super-massive black hole with mass $M\simeq 2.6\times 10^6$ M${}_{\odot }$. However, the black hole hypothesis, which theoretically implies a luminosity $\simeq 10^{41}$ erg s${}^{-1}$, runs into problems if one takes into account that the observed luminosity, from radio to $\gamma$-ray wavelengths, is below $10^{37}$ erg s${}^{-1}$. In order to solve this blackness problem, alternative models have been recently proposed. In particular, it has been suggested that the Galactic Center hosts a ball made up by non-baryonic matter (e.g. massive neutrinos and anti-neutrinos) in which the degeneracy pressure of fermions balances their self-gravity. Requiring to be consistent with all the available observations towards the Galactic Center allows us to put severe astrophysical constraints on the neutrino ball parameters. The presence of such an object in the Galactic Center may be excluded if the constituent neutrino mass $m_{\nu }$ is $\ut> 24$ keV, while if $m_ν\ut< 24$ keV observations can not give a definite answer.

9 pages, 3 figures, in press on Astronomy and Astrophysics

References in corpus (16)

• A New Dark Matter Candidate: Non-thermal Sterile Neutrinos
• High Proper Motion Stars in the Vicinity of Sgr A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
• Advection-Dominated Accretion Model of Sagittarius A*: Evidence for a Black Hole at the Galactic Center
• Substructure and halo density profiles in a Warm Dark Matter Cosmology
• Ultrahigh energy neutrino scattering onto relic light neutrinos in galactic halo as a possible source of highest energy extragalactic cosmic rays
• A supermassive boson star at the galactic center?
• Sgr A* Polarization: No ADAF, Low Accretion Rate, and Non-Thermal Synchrotron Emission
• Cosmological and astrophysical bounds on a heavy sterile neutrino and the KARMEN anomaly
• Dark matter concentration in the galactic center
• Stars and Halos of Degenerate Relativistic Heavy-Neutrino and Neutralino Matter
• Astrophysical implications of gravitational microlensing of gravitational waves
• Probing the nature of compact dark object at the Galactic Center by gravitational lensing
• Old Isolated Accreting Neutron Stars: The Diffuse X--ray Emission From The Galactic Center
• Cerenkov radiation and scalar stars
• Neutrino Balls and Gamma-Ray Bursts
• ROSAT/ASCA Observations of a Serendipitous BL Lac Object PKS 2316-423: The Variable High-Energy Tail of Synchrotron Radiation

Cited by in corpus (10)

• Neutrinos in cosmology
• The Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science
• Constraints on tidal charge of the supermassive black hole at the Galactic Center with trajectories of bright stars
• Jeans mass-radius relation of self-gravitating Bose-Einstein condensates and typical parameters of the dark matter particle
• Statistical mechanics of self-gravitating systems in general relativity: I. The quantum Fermi gas
• Constraints on Yukawa gravity parameters from observations of bright stars
• The black hole at the Galactic Center: observations and models
• Neutrino condensates at center of galaxies as background for the MSW mechanism
• Degenerate Fermi gas perturbations at standard background cosmology
• Supermassive black holes may be limited by the Holographic Bound