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SDSS--IV MaNGA : The Inner Density Slopes of nearby galaxies
- Source :
- Monthly Notices of the Royal Astronomical Society, Monthly notices of the Royal Astronomical Society, 2019, Vol.490(2), pp.2124-2138 [Peer Reviewed Journal]
- Publication Year :
- 2019
- Publisher :
- arXiv, 2019.
-
Abstract
- We derive the mass weighted total density slopes within the effective (half-light) radius, $\gamma'$, for more than 2000 nearby galaxies from the SDSS-IV MaNGA survey using Jeans-anisotropic-models applied to IFU observations. Our galaxies span a wide range of the stellar mass ($10^9$ $M_{\rm \odot}< M_* < 10^{12}$ M$_{\odot}$) and the velocity dispersion (30 km/s $< \sigma_v 100$ km/s, the density slope has a mean value $\langle \gamma^{\prime} \rangle = 2.24$ and a dispersion $\sigma_{\gamma}=0.22$, almost independent of velocity dispersion. A clear turn over in the $\gamma'-\sigma_v$ relation is present at $\sigma\sim 100$ km/s, below which the density slope decreases rapidly with $\sigma_v$. Our analysis shows that a large fraction of dwarf galaxies (below $M_* = 10^{10}$ M$_{\odot}$) have total density slopes shallower than 1, which implies that they may reside in cold dark matter halos with shallow density slopes. We compare our results with that of galaxies in hydrodynamical simulations of EAGLE, Illustris and IllustrisTNG projects, and find all simulations predict shallower density slopes for massive galaxies with high $\sigma_v$. Finally, we explore the dependence of $\gamma'$ on the positions of galaxies in halos, namely centrals vs. satellites, and find that for the same velocity dispersion, the amplitude of $\gamma'$ is higher for satellite galaxies by about 0.1.<br />Comment: 11 pages, 10 figures, submitted to MNRAS
- Subjects :
- Physics
Cold dark matter
Stellar mass
010308 nuclear & particles physics
Velocity dispersion
FOS: Physical sciences
Astronomy and Astrophysics
Radius
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics - Astrophysics of Galaxies
01 natural sciences
Galaxy
Amplitude
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
0103 physical sciences
Satellite galaxy
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Dwarf galaxy
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society, Monthly notices of the Royal Astronomical Society, 2019, Vol.490(2), pp.2124-2138 [Peer Reviewed Journal]
- Accession number :
- edsair.doi.dedup.....88b97a993ecff206709f4c8baef741e6
- Full Text :
- https://doi.org/10.48550/arxiv.1903.09282