Skip to main content Accessibility help
×
Home

Stellar Populations of Decoupled Cores in E/S0 Galaxies with sauron and oasis

  • Richard M. McDermid (a1), Eric Emsellem (a2), Kristen L. Shapiro (a3), Roland Bacon (a2), Martin Bureau (a4), Michele Cappellari (a1) (a4), Roger L. Davies (a4), Tim de Zeeuw (a1), Jesús Falcón-Barroso (a1) (a5), Davor Krajnović (a4), Harald Kuntschner (a6), Reynier F. Peletier (a7) and Marc Sarzi (a8)...

Abstract

We summarize results from McDermid et al. (2006), who present a set of follow-up observations of the sauron representative survey of early-type galaxies. We used the oasis integral-field spectrograph (while at the Canada-France-Hawaii Telescope) to obtain high spatial resolution spectra of 28 elliptical and lenticular galaxies. These seeing-limited data have on average twice the spatial resolution of the sauron data, albeit over a smaller field. These new data reveal previously unresolved features in these objects' stellar kinematics, stellar populations, and ionized gas properties. In this contribution, we focus on the discovery of a population of compact kinematically decoupled cores in a number of our sample galaxies. These compact cores are related to regions of young stars, and counter-rotate around the host galaxy's minor axis. We compare these objects to previously known decoupled components, which in contrast are composed of old stars, and which rotate around axes unrelated to the host galaxy's kinematics or shape. A key difference between these two kinds of decoupled cores are their physical size and relative mass. The compact decoupled cores are smaller than a few hundred parsec, and constitute less than a few percent of the total galaxy mass. The ‘classical’ decoupled cores exist on kiloparsec scales, and comprise around a factor 10 more mass. We suggest that the small components are only found with young ages because of their low mass-to-light ratio. We show that after a few Gyrs, these components ‘fade’ into the background galaxy, making them more difficult to detect. We draw the following conclusions: 1) young stars found in early-type galaxies are very often associated with centrally-concentrated counter-rotating components; 2) the small mass fraction and kinematic decoupling of these cores suggests that the star formation is associated to minor accretion events, which effectively drive the spread in luminosity-weighted ages found in early-type galaxies; and 3) such decoupled components may be common in all early-type galaxies, but not directly observed due to their small contribution to the total galaxy light at older ages.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Stellar Populations of Decoupled Cores in E/S0 Galaxies with sauron and oasis
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Stellar Populations of Decoupled Cores in E/S0 Galaxies with sauron and oasis
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Stellar Populations of Decoupled Cores in E/S0 Galaxies with sauron and oasis
      Available formats
      ×

Copyright

References

Hide All
Bacon, R., Copin, Y., Monnet, G., et al. 2001, MNRAS 326, 23
Bruzual, G., & Charlot, S. 2003, MNRAS 344, 1000
Burstein, D., Faber, S. M., Gaskell, C. M., & Krumm, N. 1984, ApJ 287, 586
McDermid, R. M., Emsellem, E., Shapiro, K. L., et al. 2006, MNRAS 373, 906
Proctor, R. N., Forbes, D. A., & Beasley, M. A. 2004, MNRAS 355, 1327
Sarzi, M., et al. 2006, MNRAS 366, 1151
Thomas, D., Maraston, C., & Bender, R. 2003, MNRAS 339, 897
MathJax
MathJax is a JavaScript display engine for mathematics. For more information see http://www.mathjax.org.

Keywords

Stellar Populations of Decoupled Cores in E/S0 Galaxies with sauron and oasis

  • Richard M. McDermid (a1), Eric Emsellem (a2), Kristen L. Shapiro (a3), Roland Bacon (a2), Martin Bureau (a4), Michele Cappellari (a1) (a4), Roger L. Davies (a4), Tim de Zeeuw (a1), Jesús Falcón-Barroso (a1) (a5), Davor Krajnović (a4), Harald Kuntschner (a6), Reynier F. Peletier (a7) and Marc Sarzi (a8)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed