I summarize the results of our multifrequency study of the helically twisted jets in the Seyfert galaxy NGC 4258. [N II], Hα, and [O III] Fabry-Perot datacubes obtained with the HIFI system on the U. Hawaii 2.2m telescope form the basis of this work. ROSAT x-ray multiband images (HRI & PSPC), CO spectra, and unpublished VLA 6 and 20 cm maps are correlated with these spectral grids. Together these data reveal clear signatures of high-velocity (> 300 km s−1) shocks along the jets that suggest efficient entrainment of ambient molecular gas.

We report on an ongoing survey of the extended line emission in high redshift radio galaxies, using a tunable Fabry-Perot etalon. Some results and suitable models are presented for individual sources.

Narrow-band images of the ringed Seyfert 2 galaxy NGC 2273 = Mark 620 taken with tunable Fabry-Perot interferometer are presented. Some preliminary contusions are outlined.

A major astrophysical problem is related to the fact that rotation curves (RCs)) of galaxies are flat. The presence of a dark halo is most often invoked to explain that. Some controversies exist concerning the existence of a dark halo for galaxies in very hostile environments like in center of clusters. Using a scanning Fabry-Perot interferometer, we have observed Hα velocity fields of a sample of 38 galaxies located in 7 different clusters of galaxies. From this sample, our conclusion is that spirals located in the central part of clusters do not have decreasing RCs within the optical radius.

Some elliptical galaxies possess an extended gaseous disk which is usually detected from Hα and [Nil] emission. 3-D ”Cigale” observations of two of these objects, NGC 1052 and NGC 404, show the evidence of peculiar dynamics a nd in one case multiple profiles of faint extended gas which are probably from different origins. In NGC 1052, the decoupled kinematics of the gas and the stellar systems favors the hypothesis of an external origin of the interstellar matter, while in NGC 404, coherence of the stars and gas axis, as well as the low gas velocity dispersion favors an inner origin of the gas from the stars themselves.

The use of TAURUS 2, a Fabry-Perot imaging spectrograph, for the study of the kinematics and the dynamics of giant extragalactic HII regions in nearby galaxies is discussed. The technical aspects of the instrument, together with the procedures adopted for data analysis and reduction, and some of the first scientific results of our programme are also presented.

Observations of the giant irregular galaxy NGC 4449 are being used to study the correlations between the diameter or luminosity and the velocity dispersion of its giant HII regions (GHRs), understanding as GHRs those HII regions with supersonic velocity dispersions. In the central part of this galaxy the HII regions overlap, and also there is a strong, morphologically diffuse emission that permeates the main body of NGC 4449, both effects making difficult the detection, identification and separation of HII regions. We have developed new techniques to solve these problems, obtaining HII regions parameters equivalent to the ones that would be got if the HII regions did not overlap and if the diffuse emission did not exist.

The Sc-galaxy NGC 6181 was observed at the 6m telescope with the Fabry-Perot interferometer CIGALE in Hα emission. A ring-like zone of strong radial gas motions at the radius of 1.8 kpc was found.

We present the results of a kinematic survey of the Small Magellanic Cloud, performed with a scanning FP interferometer mainly at Hα. These data allow us to study the overall dynamics of the ionized hydrogen of this galaxy as well as the kinematics of classes of objects. In this presentation we exemplify how the availability of data in several wavelengths can be very useful in establishing the nature of large nebular complexes of the Small Magellanic Cloud. Our kinematic study allows us to discriminate faint shocked nebulae (such as supernova remnants) inside bright HII regions. This is confirmed by recently available radio and X-ray data.

The LMC is being surveyed in the Hα emission line with a scanning Fabry-Perot interferometer, attached to the 36 cm telescope of the Observatoire de Marseille. The present results concern the kinematical mapping of bright nebulae; it shows that the kinetic energy involved in the gas motion is closely related to the evolutionary stage of the embedded stars. In particular, in the 30 Dor nebula, a few one-peaked line profiles remain at the boundaries of the shells, among the numerous split areas. The 50-100 pc shells exhibit a relatively usual spherical expansion, with velocities in the same range at the boundaries. On the contrary, the 10-20 pc shells of the central core show different velocities of the one-peak sides of the shells.

An Hα Survey of the Milky Way is being led at La Silla with a small telescope equipped with a scanning Fabry-Perot interferometer and IPCS. This Survey gives detailed Hα maps with a 9” spatial resolution and radial velocity maps with a 5km/s resolution. About 200 fields (38’×38’) have been already observed along the galactic plane. They furnish mosaics ranging from galactic longitude 234° to 350°. Combined with distances of exciting stars and radio data our kinematic data of the ionized gas enable to draw precisely the spiral arms of our Galaxy. Examples of the results obtained are given for galactic longitudes 234°, 283°, 290°, 298°, 328° and 338°.

A three-dimensional model of the [O III] λ5007 line-emitting gas in the Crab Nebula has been developed from imaging spectroscopy taken with the Goddard Fabry-Perot Imager mounted on the McGraw-Hill 1.3m telescope of Michigan-Dartmouth-MIT Observatory. Several interesting morphological features revealed in three-dimensional isophotal displays are discussed.

A program of 3-D spectrophotometry of emission nebulae being carried out at the Ohio State University will be described. We have had considerable success combining Fabry-Perot imaging, long-slit spectroscopy, and narrowband filter imaging into a hybrid 3-D spectroscopic approach that we have used to obtain detailed spectrophotometric maps of the density, temperature, extinction, and ionization in HII regions and Planetary Nebulae. The centerpiece instrument of this effort, the OSU Imaging Fabry-Perot Spectrograph (IFPS), will be described, and scientific results illustrative of our work will be presented.

N30 is a 80×330 pc nebula, seen in projection to the North of the LMC. At the position of the nebula, the neutral HI gas is distributed within two layers, with respective heliocentric velocities of 303 km s−1 for the major disk component, and 285 km s−1 for the low-velocity component (Luks & Rohlf 1992). The respective positions of the HI components along the line of sight are not known, nor is the distance between the HI layers, nor their thickness. N30 has been observed with the “survey Hα” equipment of the Observatoire de Marseille (see Rosado et al, and Marcelin et al.,this meeting), giving a 38’ square field (spatial resolution of 9“×9”) and using two scanning Fabry-Perot interferometers, the first one having a spectral sampling step of 15.7 km s−1, and the second one of 4.8 km s−1. No splitting of the line profile is visible, excluding large inner motions. The main emissions measured in N30 and also in all its 8 nearby bright and faint nebulae have heliocentric velocities in the range 302-315 km s−1. Such a velocity shows that all the nebulae are situated inside the HI disk component, following their exciting stars.

We present a study of the velocity profiles of the v=l-0 S(1) transition of molecular hydrogen (H2) towards the star forming region of OMC-1. A three dimensional data cube is presented which displays the spatial distribution as well as the velocity structure of the H2 emission. A brief description of the data acquisition, reduction and analysis is given.

The three dimensional aspect of the data has allowed us to re-examine the kinematic nature of the region. The results reveal a number of isolated sources which posses asymmetric velocity profiles which can be modelled by bow C-shocks. The implication is that these sources are compact knots of material which were involved in some explosive event, possibly associated with the luminous source IRc2, and are ploughing into the dense molecular disk around IRc2. It is likely that these bullets are associated with those discovered by Allen & Burton (1993).

Fabry-Perot interferometers have been applied in a focal reducer to observe radiation from atoms and molecules in comets and in the Io torus. Tunable Fabry-Perot interferometers have been used as narrowband filters, and an etalon with fixed airgap in classical arrangement was employed for the measurement of Doppler shifts and for narrow-line photometry.

The instrument presented here is based on the combined use of a Universal Birefringent Filter (UBF) and a Fabry-Perot Interferometer (FPI) to obtain narrow-band filtergrams with a CCD. Scanning through a Fraunhofer line with a sufficient number of wavelength settings is accomplished within a few seconds by tuning only the FPI. The two-dimensional spectrometer in the German Vacuum Tower Telescope (VTT)/Tenerife was used to take observations of high spatial, spectral, and temporal resolution, yielding a wide range of results. Since recently, additional information on the solar magnetic field is obtained with it.

In order to obtain information on the magnetic field on the sun in two spatial dimensions, a spectro-polarimeter of high spatial, spectral, and temporal resolution was built in the German Vacuum Tower Telescope (VTT) at the Observatorio del Teide/Tenerife. The two-dimensional spectrometer in the VTT, using a Universal Birefringent Filter (UBF) and a Fabry-Perot Interferometer (FPI) to obtain narrow-band nltergrams with a spectral resolution of the order of 3.105 (approx. 22 mÅ at CE5; at 6303 Å) and a spatial resolution of 0.2 arcsec/pixel (Bendlin et al. 1992, Bendlin and Volkmer 1993), was extended to work as a spectropolarimeter for measuring Stokes-I and Stokes-V profiles.

Spectronebulagraph, an automated observation system of tridimensional spectroscopy with a long slit spectrograph, is now in operation at the 188 cm telescope of the Okayama Astrophysical Observatory. This system is based on the local area net work of personal computers which control the telescope, the autoguider, the Cassegrain spectrograph and its CCD camera. Effects of variable atmospheric transmission during scans of target objects are removed by performing a set of two orthogonal scans and the data processing.

A new spectrograph is now under development for the telescope. This instrument has multiple modes for tridimensional spectroscopy, i.e., the filter imagery mode, the imaging Fabry-Perot interferometer mode, a slit spectrograph mode for Spectronebulagraph, and the microlens array spectrograph (TIGER) mode. For the last mode, a dual preoptics to get simultaneously the sky background is introduced and achromatization of the microlenses is tried. This project is a part of development of a prototype instrument for the SUBARU telescope.

The researches into extended emission line region (EELR) give us the valuable informations about the nucleus. A recent study of the EELR in the Seyfert 1 galaxy NGC 4151 by Yoshida and Ohtani (1993) have revealed that a strongly asymmetric radiation field in this typical Seyfert 1. They have suggested the anisotropy may be caused inside the BLR. It is important to examine if any other Seyfert 1 galaxy has an anisotropic nuclear radiation.

The famous Seyfert 1 galaxy NGC 3516 has EELR which extends ∼ 10” on either side of the nucleus. The morphology of the EELR is Z-shape. This nearby (D=38.9Mpc) galaxy is of type SBO for which the object is expected to be free from contamination by HII regions and dust clouds.