Using The Hubble Space Telescope's Space Telescope Imaging Spectrograph (HST's STIS ), observations of the [O III] emission from the narrow-line region (NLR) of NGC 4151 were obtained and radial velocities determined. Five orbits of HST time were used to obtain spectra at five parallel slit configurations, at a position angle of 58 o , with spatial resolution 0 ′′ .2 across and 0 ′′ .1 along each slit. A spectral resolving power (∆λ/λ) of ∼9,000 with the G430M grating gave velocity measurements accurate to ∼34 km s −1 . A kinematic model was generated to match the radial velocities, for comparison to previous kinematic models of biconical radial outflow developed for low-dispersion spectra at two slit positions. The new high-resolution spectra permit the measurement of accurate velocity dispersions for each radial-velocity component. The full-width at half-maximum (FWHM) reaches a maximum of 1000 km s −1 near the nucleus, and generally decreases with increasing distance to about 100 km s −1 in the Based on observations made with the NASA/ESA Hubble Space Telescope. STScI is operated bt the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with proposal GTO-8473

We present a study of high-resolution long-slit spectra of the narrow-line region (NLR) in NGC 1068 obtained with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope (HST ). The spectra were retrieved from the Multimission Archive at the Space Telescope Science Institute obtained from two visits and seven orbits of HST time. We also obtained MERLIN radio maps of the center of NGC 1068 to examine the dependence of the NLR cloud velocities on the radio structure. The radial velocities and velocity dispersions of the bright NLR clouds appear to be unaffected by the radio knots, indicating that the radio jet is not the principal driving force on the outflowing NLR clouds. However, the velocities of the fainter NLR clouds are split near knots in the jet, indicating a possible interaction. Biconical outflow models were generated to match the data and for comparison to previous models done with lower dispersion observations. The general trend is an increase in radial velocity roughly proportional to distance from the nucleus followed by a linear decrease after roughly 100 pc similar to that seen in other Seyfert galaxies, indicating common acceleration and deceleration mechanisms.

We present dynamical models based on a study of high-resolution long-slit spectra of the narrow-line region (NLR) in NGC 1068 obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST ). The dynamical models consider the radiative force due to the active galactic nucleus (AGN), gravitational forces from the supermassive black hole (SMBH), nuclear stellar cluster, and galactic bulge, and a drag force due to the NLR clouds interacting with a hot ambient medium. The derived velocity profile of the NLR gas is compared to that obtained from our previous kinematic models of the NLR, using a simple biconical geometry for the outflowing NLR clouds. The results show that the acceleration profile due to radiative line driving is too steep to fit the data and that gravitational forces alone cannot slow the clouds down, but with drag forces included, the clouds can slow down to the systemic velocity over the range 100Y400 pc, as observed. However, we are not able to match the gradual acceleration of the NLR clouds from $0 to 100 pc, indicating the need for additional dynamical studies.

Using the Multimission Archives at Space Telescope (MAST), we have extracted spectra and determined continuum light curves for 175 Seyfert Galaxies that have been observed with the International Ultraviolet Explorer (IUE) and the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST). To obtain the light curves as a function of Julian Date, we used fix bins in the object's rest frame, and measured small regions (between 30 and 60Å) of each spectrum's continuum flux in the range 1150Å to 3200Å. We provide access to the UV light curves and other basic information about the observations in tabular and graphical form via the Internet at

We present an investigation of H-alpha emission line variations observed in the massive Algol binary, RY Per. We give new radial velocity data for the secondary based upon our optical spectra and for the primary based upon high dispersion UV spectra. We present revised orbital elements and an estimate of the primary's projected rotational velocity (which indicates that the primary is rotating 7 times faster than synchronous). We use a Doppler tomography algorithm to reconstruct the individual primary and secondary spectra in the region of H-alpha, and we subtract the latter from each of our observations to obtain profiles of the primary and its disk alone. Our H-alpha observations of RY Per show that the mass gaining primary is surrounded by a persistent but time variable accretion disk. The profile that is observed outside-of-eclipse has weak, double-peaked emission flanking a deep central absorption, and we find that these properties can be reproduced by a disk model that includes the absorption of photospheric light by the band of the disk seen in projection against the face of the star. We developed a new method to reconstruct the disk surface density distribution from the ensemble of H-alpha profiles observed around the orbit, and this method accounts for the effects of disk occultation by the stellar components, the obscuration of the primary by the disk, and flux contributions from optically thick disk elements. The resulting surface density distribution is elongated along the axis joining the stars, in the same way as seen in hydrodynamical simulations of gas flows that strike the mass gainer near trailing edge of the star. This type of gas stream configuration is optimal for the transfer of angular momentum, and we show that rapid rotation is found in other Algols that have passed through a similar stage.Comment: 39 pages, 12 figures, ApJ in press, 2004 June 20 issu