COOL INTERSTELLAR GAS IN THE CORE OF M87
Session 23 -- Emission-Line, Starburst and Ultra-Luminous Galaxies
Oral presentation, Monday, 2:30-4:00, Wheeler Room

## [23.05] COOL INTERSTELLAR GAS IN THE CORE OF M87

Z.Tsvetanov (JHU), H.Ford (JHU/STScI), G.Kriss (JHU), I.Evans (STScI)

\def\as{{$'\!.\!'$}} \def\MgI{Mg~{\sc i}} \def\MgII{Mg~{\sc ii}}

To study the nucleus and jet of the giant elliptical galaxy M87, spectra expanding from Ly$\alpha$ through H$\alpha$ were taken with the HST Faint Object Spectrograph. One of our goals is to use the absorption lines in the nonthermal continua of the jet and nucleus to investigate the warm gas near the nucleus and the hot gas in the corona. Several prominent interstellar absorption lines such as \MgI\ and \MgII\ are registered in the spectrum of the nucleus taken through the 0\as3 aperture ($\sim$23 pc at a distance of 16 Mpc). The lines have appreciable equivalent width and are quite narrow (FWHM$\leq$200 km s$^{-1}$), suggesting the presence of a cool interstellar gas in the core of M87, possibly dynamically distinct from the stellar population. The same absorption lines are not detected against the featureless synchrotron continuum of the brightest knot A in the jet of M\,87 at a projected distance of 12\as5 (1 kpc) from the nucleus. We will discuss the physical conditions in the cool gas and its possible origin. \\

This work is supported by NASA Grant NAS 5-1630 to the FOS team.