Photospheric Abundances of the Hot Stars in NGC 1399 and Limits on the Fornax Cluster Cooling Flow

We present far-UV spectroscopy of the giant elliptical galaxy NGC 1399,obtained with the Far Ultraviolet Spectroscopic Explorer. Of all quiescentellipticals, NGC 1399 has the strongest known ``UV upturn'' -- a sharp spectralrise shortward of 2500 A. It is now well-established that this emission comesfrom hot horizontal branch (HB) stars and their progeny; however, the chemicalcomposition of these stars has been the subject of a long-standing debate. Forthe first time in observations of any elliptical galaxy, our spectra clearlyshow photospheric metallic absorption lines within the UV upturn. The abundanceof N is at 45% solar, Si is at 13% solar, and C is at 2% solar. Such abundanceanomalies are a natural consequence of gravitational diffusion. Thesephotospheric abundances fall in the range observed for subdwarf B stars of theGalactic field. Although NGC1399 is at the center of the Fornax cluster, we find no evidencefor O VI cooling flow emission. The upper limit to 1032,1038 emission is3.9E-15 erg/s/cm2, equivalent to 0.14 M_sun/yr, and less than that predicted bysimple cooling flow models of the NGC 1399 X-ray luminosity.Comment: 4 pages, Latex. 2 figures. Uses corrected version of emulateapj.sty and apjfonts.sty (included). Accepted for publication in ApJ Letters. Revised figure placemen