Conference Paper

VELOCITY DISPERSION PROFILE OF "Cetus" DWARF SPHEROIDAL GALAXY

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Dwarf spheroidal galaxies are representing the largest mass dis- crepancies in the local universe. Apart from that, “Cetus” a dSph discovered by Whiting et al. (1999) which is also the farthest known dwarf spheroidal galaxy residing on the boundaries of the local group of galaxies is of increased interest, not only because it can constrain the total mass of the local group, but also because of the possibility of being an isolated dSph galaxy. The internal structure of isolated dSph galaxies can shed light on the “position-morphology” relation of the distribution of dwarf galaxies in the local group. To this end, we have used the most complete data sample provided recently by Kirby et al. (2014) to study the internal kinematics of Cetus in order to estimate its Virial mass and shed light on the “isolation” probability by studying interaction history of Cetus with either M31 or the Milky Way. We solved the Jean’s equation with different velocity dispersion anisotropy models and could find the best fit to the observed line of sight velocity dispersion at an expense of ≈ 2 × 108 M , which implies a closest distance of encounter to be about 120kpc which compared to the previous study by McConnachie et al. (2006) shows a decrease in the peri-galactic distance, this also increases the possibility of pre- vious gravitational interaction. Also we could reveal an anisotropy of about β = 0.5 at the inner regions and also β = −0.5 at the outer regions which also supports previous interactions as deviation from the isotropic model.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

ResearchGate has not been able to resolve any citations for this publication.
  • E N Kirby
  • J S Bullock
  • M Boylan-Kolchin
  • M Kaplinghat
  • J G Cohen
Kirby, E. N., Bullock, J.S., Boylan-Kolchin, M., Kaplinghat, M.,& Cohen, J. G. 2014, MNRAS, 439, 1015 [2] McConnachie, A. W.,& Irwin,M. J. 2006, MNRAS, 365,1263
MNRAS, 363 1263 ONGOING RESEARCH 1. The predictions of MOND can also be compared to the dark matter model. 2. Detailed study of the previous encounter of Cetus with M31/MW are required. 3. Extending this analysis to other dSphs with the enhanced data sample of
  • G A Mamon
  • E L Łokas
  • Kirby
Mamon, G.A.,& Łokas, E. L. 2005, MNRAS, 363 1263 ONGOING RESEARCH 1. The predictions of MOND can also be compared to the dark matter model. 2. Detailed study of the previous encounter of Cetus with M31/MW are required. 3. Extending this analysis to other dSphs with the enhanced data sample of Kirby et al. (2014)