Probing the halo of Centaurus A: a merger dynamical model for the PN population
| dc.creator | Mathieu, A. | |
| dc.creator | Dejonghe, H. | |
| dc.creator | Hui, X. | |
| dc.date | 1995-10-16 | |
| dc.date.accessioned | 2026-07-07T02:20:18Z | |
| dc.date.available | 2026-07-07T02:20:18Z | |
| dc.description | Photometry and kinematics of the giant elliptical galaxy NGC~5128 (Centaurus~A) based on planetary nebulae observations (Hui~\etal 1995) are used to build dynamical models which allow us to infer the presence of a dark matter halo. To this end, we apply a Quadratic Programming method. Constant mass-to-light ratio models fail to reproduce the major axis velocity dispersion measurements at large radii: the profile of this kind of models falls off too steeply when compared to the observations, clearly suggesting the necessity of including a dark component in the halo. By assuming a mass-to-light ratio which is increasing with radius, the model satisfactorily matches the observations. The total mass for the best fit model is $\sim4\times10^{11}M_\odot$ of which about 50\% is dark matter. However, models with different total masses and dark halos are also consistent with the data; we estimate that the total mass of Cen~A within 50~kpc may vary between $3\times10^{11}M_\odot$ and $5\times10^{11}M_\odot$. The best fit model consists of 75\% of stars rotating around the short axis $z$ and 25\% of stars rotating around the long axis $x$. Finally, the morphology of the projected velocity field is analyzed using Statler's classification criteria (Statler 1991). We find that the appearance of our velocity field is compatible with a type 'Nn' or 'Nd'. | |
| dc.description | 13 pages, uuencoded compressed postscript, without figures. The full postscript version, including all 14 figures, is available via anonymous ftp at ftp://naos.rug.ac.be/pub/cena.ps.Z | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9510079 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9510079 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/10169 | |
| dc.subject | Astrophysics | |
| dc.title | Probing the halo of Centaurus A: a merger dynamical model for the PN population | |
| dc.type | text |