Black Holes in Centers of Disk Galaxies - Spectroscopy with a Wide Slit

Motivated by STIS observations of more than 50 nearby galactic nuclei, we consider long-slit emission-line spectra when the slit is wider than the instrumental PSF. The finite width of the slit generates complex patterns in the spectra that can have considerable diagnostic power if they are modeled with adequate sophistication. They allowed us to develop a new method for estimating the BH mass that gives fuller information and higher sensitivity to BH detection than traditional methods.