6 research outputs found
Highlights on gamma rays, neutrinos and antiprotons from TeV Dark Matter
We analyze the possibility that the HESS γ-ray source at the Galactic center could be explained as the secondary flux produced by annihilation of TeV dark matter (DM) particles with locally enhanced density, in a region spatially compatible with the HESS observations themselves. We study the inner 100 pc considering (i) the extrapolation of several density profiles from state-of-the-art N-body þ hydrodynamics simulations of Milky Way-like galaxies, (ii) the DM spike induced by the black hole, and (iii) the DM particles scattering off by bulge stars. We show that in some cases the DM spike may provide the enhancement in the flux required to explain the cutoff in the HESS J1745-290γ-ray spectra as TeV DM. In other cases, it may help to describe the spatial tail reported by HESS II at angular scales ≲0.54° toward Sgr A*
SDSS-IV MaNGA : the MaNGA dwarf galaxy sample presentation
M.C.D. acknowledges support from CONACYT "Ciencia de Frontera" grant 320199. M.C.D. and H.M.H.T. acknowledge support from UC MEXUS-CONACYT grant CN-17-128. A.R.P. acknowledges support from the CONACyT "Ciencia Basica" grant 285721. E.A.O. acknowledges support from the SECTEI (Secretaría de Educación, Ciencia, Tecnología e Innovación de la Ciudad de México) under the Postdoctoral Fellowship SECTEI/170/2021 and CM-SECTEI/303/2021. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions.We present the MaNGA Dwarf galaxy (MaNDala) Value Added Catalog (VAC), from the final release of the Sloan Digital Sky Survey-IV program. MaNDala consists of 136 randomly selected bright dwarf galaxies with M* −18.5, making it the largest integral field spectroscopy homogeneous sample of dwarf galaxies. We release a photometric analysis of the g, r, and z broadband imaging based on the DESI Legacy Imaging Surveys, as well as a spectroscopic analysis based on the Pipe3D SDSS-IV VAC. Our release includes the surface brightness (SB), geometric parameters, and color profiles, Sérsic fits as well as stellar population properties (such as stellar ages, metallicities, and star formation histories), and emission lines' fluxes within the FOV and the effective radii of the galaxies. We find that the majority of the MaNDala galaxies are star-forming late-type galaxies with 〈nSersic,r〉∼1.6 that are centrals (central/satellite dichotomy). MaNDala covers a large range of SB values (we find 11 candidate ultra-diffuse galaxies and three compact ones), filling the gap between classical dwarfs and low-mass galaxies in the Kormendy Diagram and in the size–mass/luminosity relation, which seems to flatten at 108 2, while the last 20% was at 〈z〉 < 0.3. Finally, a bending of the sSFR-M * relation at M* ∼ 109 M⊙ for the main-sequence galaxies seems to be supported by MaNDala.Publisher PDFPeer reviewe