Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994mnras.271..693h&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Vol. 271, NO. 3/DEC1, P. 693, 1994
Astronomy and Astrophysics
Astronomy
44
Scientific paper
We have observed 46 giant stars in the Ursa Minor dwarf spheroidal (dSph) galaxy and obtained high-quality spectra for 35 of these. The velocity dispersion of the sample calculated by a maximum likelihood method is 7.5_-0.9_^+1.0^ km s^-1^ and the mean velocity is -249.2 +/- 1.5 km s^- 1^. There is evidence for rotation around the major axis: a straight line fit, equivalent to solid body rotation, gives a gradient of -4.7_-2.2_^+2.0^ km s^-1^ per 100 pc from the axis, where the positive distances are to the north-west of the major axis. This discovery adds evidence to the suggestion that Ursa Minor may be being tidally disrupted. If further work eliminates this possibility, then, assuming dynamical equilibrium, isotropy in the velocity dispersion (which is 6.7_-0.8_^+0.9^ km s^-1^ when the rotation has been subtracted) and a negligible contribution from binary stars, the core mass-to-light ratio is 59_-25_^+41^ M_sun_/L_sun_ and the total mass-to-light ratio is 40_-17_^+29^ M_sun_/L_sun_, implying the presence of large quantities of dark matter.
Carter David
Gilmore Gerard
Hargreaves J. C.
Irwin Mary Jane
No associations
LandOfFree
A Dynamical Study of the Ursa-Minor Dwarf Spheroidal Galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Dynamical Study of the Ursa-Minor Dwarf Spheroidal Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Dynamical Study of the Ursa-Minor Dwarf Spheroidal Galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1412154