Skip to main content Accessibility help
×
Home

Dynamics in the Centres of Triaxial Elliptical Galaxies

  • Ortwin E. Gerhard (a1)

Abstract

Orbits in the inner kpc of a triaxial galaxy are discussed, taking into account the effect of a central density concentration like a massive black hole, a dense stellar nucleus, or a de Vaucouleurs-type cusp. Since the box orbits that form the backbone of a triaxial galaxy pass arbitrarily close to the centre after long enough time, they will eventually be subjected to large-angle deflections by a central point mass, and the triaxiality of the inner part of the system will thereby be destroyed. A 108 M black hole is estimated to affect box orbits out to 1kpc in a Hubble time, while a similar influence of the observed (extended) nucleus in M31 reaches out to 500pc in the bulge. Regular box orbits persist, however, in systems with singular central density profiles such as implied by carrying the r1/4 law all the way to the centre. This result can be approximately understood in terms of the frequency ratio Ωrθ remaining close to the harmonic value of 2 for many orbits in the corresponding spherical potential. Finally, I discuss observable consequences of the box orbit scattering process and future work, and use the presence of isophote twists in the central parts of a number of elliptical galaxies to obtain approximate upper limits on the masses of the black holes these systems may contain.

    • 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.

      Dynamics in the Centres of Triaxial Elliptical Galaxies
      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.

      Dynamics in the Centres of Triaxial Elliptical Galaxies
      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.

      Dynamics in the Centres of Triaxial Elliptical Galaxies
      Available formats
      ×

Copyright

References

Hide All
Binney, J.J., 1985. Mon. Not. R. astr. Soc. 212, 767.
Gerhard, O.E., 1986. Mon. Not. R. astr. Soc. 219, 373.
Gerhard, O.E., Binney, J.J., 1985. Mon. Not. R. astr. Soc. 216, 467.
Kormendy, J., 1985. Astrophys. J. (Letters) 292, L9.
Lauer, T.R., 1983. PhD thesis, University of California, Santa Cruz.
Lauer, T.R., 1985. Astrophys. J. 292, 104.
Light, E.S., Danielson, R.E., Schwarzschild, M., 1974. Astrophys. J. 194, 257.
Lynden-Bell, D., 1969. Nature 223, 690.
Norman, C.A., May, A., van Albada, T.S., 1985. Astrophys. J. 296, 20.
Rees, M.J., 1984. Ann. Rev. Astr. Astrophys. 22, 471.
Schwarzschild, M., 1979. Astrophys. J. 232, 236.
Schweizer, F., 1979. Astrophys. J. 233, 23.
Walker, M.F., 1974. Publs. astr. Soc. Pacif. 86, 861.
Young, P.J., 1976. Astron. J. 81, 807.

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