| Title | Beyond the Brim of the Hat: Kinematics of Globular Clusters out to Large Radii in the Sombrero Galaxy |
| Authors | Dowell, Jessica L.; Rhode, Katherine L.; Bridges, Terry J.; Zepf, Stephen E.; Gebhardt, Karl; Freeman, Ken C.; de Boer, Elizabeth Wylie |
| Bibcode | 2014AJ....147..150D Search ADS ↗ |
| Abstract | We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combining our own past measurements and velocity measurements obtained from the literature, we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24 kpc or ~5Re ), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41 kpc or ~9Re ). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that M/LV increases from 4.5 at the center to a value of 20.9 at 41 kpc (~9Re or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20 kpc (~4Re or ~7.'4) to the mass computed from X-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples. |
| Objects | 580 Objects Search NED ↙ |
