  The cluster of galaxies A1795 hosts a 46 kpc-long filament at its core, which
is clearly visible in the light of H-alpha and X-ray emission. We present
optical slit spectroscopy and deeper Chandra X-ray data of the filament. The
optical spectra reveal that the the bulk of the filament is quiescent (with
sigma < 130 km/s), although considerable velocity structure is apparent around
the powerful radio source in the central cluster galaxy, where a direct
interaction is occurring between the radio plasma and the surrounding
intracluster medium. The filament contains a clump of UV/blue continuum halfway
along its length, which we resolve into a chain of at least 5 distinct knots
using archival HST images; the optical spectrum of this clump confirm it to be
mostly comprised of O stars. It is well-removed from the central galaxy and
radio source, and is most likely an example of a group of young star clusters
condensing directly from the cooling gas in the filament. The observed spatial
offset between these knots of star formation and the peak in the optical line
emission confirms that the massive star formation is most unlikely to be
responsible for the bulk of the observed emission-line luminosity in the
filament. Some other (as yet undetermined) source of energy is required to
power and maintain the optical line-emission, yet it must not completely impede
the cooling of the X-ray gas within the filament to form the star clusters.
