AAS 197, January 2001
Session 111. Galaxy Morphology and Structure
Display, Thursday, January 11, 2001, 9:30-4:00pm, Exhibit Hall

[Previous] | [Session 111] | [Next]

[111.05] Deep Far-UV Spectroscopy of Nearby E/S0 Galaxies

R.W. O'Connell, J.R. Martin, J.D. Crane, S. Sohn (UVa), D. Burstein (ASU), R.C. Bohlin (STScI), W.B. Landsman (Raytheon ITSS/GSFC), R.T. Rood (UVa), C.-C. Wu (CSC/STScI)

We have obtained long slit HST/STIS spectra in the far-UV (1150-1700 A) of 5 bright E/S0 galaxies: M32, NGC 1399, NGC 3115, NGC 4649, and NGC 5831. With exposures up to 11,400 secs, these are among the deepest spectra yet obtained of the "UV upturn" in old stellar populations. The spectra extend to radii of 10 arcsec, and we are able to study spatial gradients and asymmetries in the far-UV light. A nuclear point source in N1399 appears to be variable and is probably the second case (after N4552, Renzini et al. 1995) of a far-UV AGN flare detected in a nearby E galaxy. With a luminosity of 8e38 erg/s, this is one of the lowest luminosity AGN's yet detected and is an important test of "advection dominated accretion flow" models for underactive AGN's. In the Local Group E galaxy M32, we detect a number of the hot post-HB stars first resolved by Brown et al. (2000) on STIS images. Finally, although the spectra have low resolution (12 or 48 A), the S/N is good enough that we detect absorption features of Si II (1260 A), C II (1335 A), Si IV (1400 A), and C IV (1550 A) and can study their radial gradients.

This work was supported in part by NASA LTSA grant NAG5-6403 and STScI grant GO-07438.

[Previous] | [Session 111] | [Next]