Showing papers by "Elaine M. Sadler published in 1993"
Abstract: We have measured line-strength indices as a function of radius in several elliptical galaxies. All of them show strong radial gradients in Mg, but much weaker gradients in Fe and Hs. The isophotes and contours of constant line-strength have the same flattening. More luminous galaxies have shallower gradients, contrary to the prediction of models of dissipative collapse. Most of the galaxies observed show weak central emission which can partially fill the Balmer absorption lines.
339 citations
TL;DR: Extended and accurate major axis kinematical profiles and line strength gradients of the elliptical galaxies NGC 4472, IC 4296, and NGC 7144 have been measured using the ESO NTT in the EMMI long-slit spectroscopic mode.
Abstract: Extended and accurate major axis kinematical profiles and line strength gradients of the elliptical galaxies NGC 4472, IC 4296, and NGC 7144 have been measured using the ESO NTT in the EMMI long-slit spectroscopic mode. For NGC 7144 the stellar rotation curve and velocity dispersion profile extend to 75″ from the center (where the surface brightness is 24.4 B-mag arcsec −2 , 2.8 mag below the sky), with typical error bars of 10 km s −1 . The flat or slowly increasing velocity dispersion profiles of these galaxies indicate that massive dark halos might dominate their dynamics
49 citations
Journal Article•
TL;DR: The morphology of the emitting regions suggests that the ionized gas usually lies in a disk which is often geometrically decoupled from the stellar body, as expected in a triaxial galaxy as mentioned in this paper.
Abstract: We present and discuss Hα+[N II] imaging observations of fifteen nearby elliptical and S0 galaxies with extended optical emission lines. The morphology of the emitting regions suggests that the ionized gas usually lies in a disk which is often geometrically decoupled from the stellar body, as expected in a triaxial galaxy. The presence of a gaseous disk makes these galaxies suitable for testing their gravitational field in a straightforward way. The presence of dust in many of the disks, together with the observed morphological properties, suggests that the ionized gas in most of these galaxies is more closely associated with the cold ISM than with the hot X-ray component
4 citations