The Stellar Velocity Field and Intrinsic Shape of NGC 1700
Session 52 -- Elliptical Galaxies
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [52.06] The Stellar Velocity Field and Intrinsic Shape of NGC 1700

Thomas S. Statler (UNC), Tammy Smecker-Hane (DAO), Gerald Cecil (UNC)

We have measured the stellar (absorption line) rotation of the elliptical galaxy NGC 1700 along four position angles, to very large radii, using the MMT. Our data extend the coverage of the stellar velocity field by a factor of 5 ($2.5$ times further in radius and twice as many PAs) beyond previous work. We have attained $10 \mbox{\,km\,s}^{-1}$ accuracy in the mean velocity $V$ out to nearly 2 effective radii ($r_e$), and errors are $<15\%$ of the maximum rotation speed out to nearly $3r_e$. We confirm the previously known counterrotating core, and also find that the velocity distribution is slightly square-shouldered and skewed in the direction of rotation. The lack of detectable minor-axis rotation and the nearly identical kinematics on the $\pm 45^\circ$ PAs, combined with extensive dynamical modeling, strongly indicate that NGC 1700 is nearly oblate. The dynamically inferred shapes of NGC 1700, NGC 3379, and NGC 4589 are not consistent with the preference for prolate-triaxial objects in current galaxy formation simulations, implying that the shapes of ellipticals may be significantly modified by dissipative processes.