Linear relation between H i circular velocity and stellar velocity dispersion in early-type galaxies, and slope of the density profiles
| العنوان: | Linear relation between H i circular velocity and stellar velocity dispersion in early-type galaxies, and slope of the density profiles |
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| المؤلفون: | Gyula I. G. Józsa, Milan den Heijer, Michele Cappellari, Paolo Serra, Tom Oosterloo |
| المساهمون: | Astronomy |
| المصدر: | Monthly Notices of the Royal Astronomical Society, 460(2), 1382-1389. Oxford University Press |
| بيانات النشر: | Oxford University Press, 2017. |
| سنة النشر: | 2017 |
| مصطلحات موضوعية: | Stellar kinematics, Stellar mass, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Tully–Fisher relation, 01 natural sciences, cD, Gravitational potential, SURFACE BRIGHTNESS GALAXIES, SUPERMASSIVE BLACK-HOLES, TULLY-FISHER RELATION, 0103 physical sciences, TO-LIGHT RATIO, galaxies: elliptical and lenticular, 010306 general physics, 010303 astronomy & astrophysics, Galaxy rotation curve, Astrophysics::Galaxy Astrophysics, galaxies: kinematics and dynamics, MASS-DISTRIBUTION, Physics, Velocity dispersion, Astronomy, Astronomy and Astrophysics, Radius, ATLAS(3D) PROJECT, Astrophysics - Astrophysics of Galaxies, Galaxy, NEUTRAL HYDROGEN, Space and Planetary Science, DARK-MATTER HALOES, Astrophysics of Galaxies (astro-ph.GA), ROTATION CURVES, galaxies: elliptical and lenticular, cD, galaxies: structure, Astrophysics::Earth and Planetary Astrophysics, SPIRAL GALAXIES |
| الوصف: | We report a tight linear relation between the HI circular velocity measured at 6 $R_{\rm e}$ and the stellar velocity dispersion measured within 1 $R_{\rm e}$ for a sample of 16 early-type galaxies with stellar mass between $10^{10}$ and $10^{11}$ $\mathrm{M}_\odot$. The key difference from previous studies is that we only use spatially resolved $v_\mathrm{circ}$(HI) measurements obtained at large radius for a sizeable sample of objects. We can therefore link a kinematical tracer of the gravitational potential in the dark-matter dominated outer regions of galaxies with one in the inner regions, where baryons control the distribution of mass. We find that $v_\mathrm{circ}$(HI) = 1.33 $\sigma_\mathrm{e}$ with an observed scatter of just 12 percent. This indicates a strong coupling between luminous and dark matter from the inner- to the outer regions of early-type galaxies, analogous to the situation in spirals and dwarf irregulars. The $v_\mathrm{circ}$(HI)-$\sigma_\mathrm{e}$ relation is shallower than those based on $v_\mathrm{circ}$ measurements obtained from stellar kinematics and modelling at smaller radius, implying that \vcirc\ declines with radius -- as in bulge-dominated spirals. Indeed, the value of $v_\mathrm{circ}$(HI) is typically 25 percent lower than the maximum $v_\mathrm{circ}$ derived at $\sim0.2\ R_\mathrm{e}$ from dynamical models. Under the assumption of power-law total density profiles $\rho \propto r^{-\gamma}$, our data imply an average logarithmic slope $\langle\gamma\rangle=2.18\pm0.03$ across the sample, with a scatter of 0.11 around this value. The average slope and scatter agree with recent results obtained from stellar kinematics alone for a different sample of early-type galaxies. Comment: MNRAS, accepted |
| وصف الملف: | application/pdf |
| تدمد: | 0035-8711 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c1df0f968ecbbc3e3c463e298c2f5b11 https://ora.ox.ac.uk/objects/uuid:e184919d-a797-4ef2-aaef-1992d06cfc4d |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....c1df0f968ecbbc3e3c463e298c2f5b11 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00358711 |
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