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Session 78 - Seyfert Galaxies.
Display session, Friday, January 09
Observations of the nuclear region of the Seyfert 1 galaxy NGC4151 have been executed using the HST Space Telescope Imaging Spectrograph (STIS). Using slitless spectroscopy the nuclear region of the galaxy was imaged in dispersed light, obtaining simultaneous spatial and velocity structure information. In addition, [OII] and [OIII] comparison images were obtained in undispersed light.
In the visible, data were obtained using both the G430M and G750M gratings with the CCD. In the ultraviolet, data were taken in mode G140M with the Multi-Anode Microchannel plate Array (MAMA). High spatial resolution, dispersed light, images of NGC4151 have been obtained in CIV, [OII], [NeIII], H\beta, [OIII], [OI], [NII], H\alpha, and [SII]. These data show emission from the narrow line region (NLR) extended out to a approximately a kiloparsec (15 arcseconds) on either side of the point-like central source.
Radial velocities and line ratios for the approximately 40 clouds resolved in the narrow-line region will be presented. From analysis of the [OIII] dispersed images, the kinematics suggest outflow within a biconical region about the nucleus, centered on the radio axis, and viewed near the edge of the cones. A few high velocity clouds are seen which do not fit this simple picture. Line ratios indicate that the NLR gas is photoionized by the central continuum source and that there may be a density gradient in the NLR.
In addition to the CIV, H\beta, and [OIII] data, emission line velocities for the [OII], [NeIII], [NII], H\alpha, and [SII] clouds will be presented.
Program listing for Friday