Tridimensional spectroscopy of the Seyfert 1 galaxy 3C 120 was carried out with Spectronebulagraph (SNG). We constructed a data cube which is free from atmospheric variations during the scans. We then separated the blended lines by deconvolving the line profiles, to obtain pure narrow-line images and narrow-line intensity ratio diagram.

We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter SNG; Kosugi et al. 1994) at Okayama Astrophysical Observatory. A detailed description about SNG is presented by Ohtani et al. elsewhere in this colloquium. We present here the results of the 3D-spectroscopy of four nearby active galaxies by using SNG.

This nearby (at distance of 5.4 Mpc) Magellanic irregular galaxy has many H II regions in its main body suggesting violent star-formation activity. We performed tridimensional observations of NGC 4449 using SNG in order to obtain detailed kinematic structure and then to investigate the star-formation mechanism of NGC 4449. Hα intensity map, Hα velocity field are shown in figure 1. As is obvious in lower panel of figure 1, no global rotational motion was detected. Most impressive feature of the velocity field is kpc-scale mosaic structure of low velocity and high velocity components. Also, many filamentary components were newly found in 3D-datacube of the SNG observation.

An efficient technique for obtaining complete spectral informations over moderately extended objects is to transform the geometry of their telescopic images to match a classical long ”slit” aperture. This anamorphosis is conveniently made with bundles of optical fibres. Such devices are especially useful when high spatial resolution and large wavelength coverage are required at the same time. We review the existing instruments based on this technique and present some typical results. We discuss also the future developments of integral field spectroscopy with optical fibres (visible or IR domains) for the new generation of very large telescopes.

TAUMOK is a joint project of the Max Planck Institut für Astronomie Heidelberg and the Thüringer Landessternwarte Tautenburg. It is based on the concept of the “Spaltspinne” (Pitz 1993) now in operation at the Calar Alto Observatory. A first describtion of the technical concept was given by Pitz et al. (1993). TAUMOK was built at the MPIA Heidelberg in collaboration with astronomers and technicians from Tautenburg. It is now in the test phase and will have its first operation at the Tautenburg telescope in the middle of this year.

The use of a Schmidt telescope gives a very wide field for multi-object spectroscopy (TAUMOK will cover a field of 2.3°) but it also requires a series of special considerations. So, some of the details of the original “Spaltspinne” were modified to meet the site specific peculiarities. The size of the ground plate was minimized and yields a central obscuration of only 60 cm in diameter. The curved field of the Schmidt focus (deviation of up to ±400 µm from the mean focal plane) is flattened by a field lens - a solution alternative to the guiding of the fiber supporting rods on a sphere.

We report the first use of a near infrared multiobject spectrograph that can acquire 1–2.5µm spectra of up to 35 objects in a 1000 arcsecond field.

A multi-function spectrograph has been built for the new 1.52 m telescope in the Sierra Nevada Observatory near Granada (Spain). It uses optical fibres for both multi-object spectroscopy and integral field spectroscopy, in addition to classical imaging and long-slit modes.

This paper deals with applications of bi(tri)dimensional spectroscopy methods to some gravitational mirages. Optical fibre devices are well adapted to the study of the structure and geometry of such phenomena. The improvement that brought bidimensional spectroscopy of few mirages is presented and the need to observe the other candidates is discussed.

Markarian 463, a system of 2 interacting/merging galaxies (E and W) has been observed with SILFID at CFHT in sub-arcsec resolution conditions. We found that both nuclei are AGNs, with the W component being a Sy 2 or LINER and the E component, hitherto known to be a “hidden” Seyfert 1, having essentially Sy 2 characteristics. The bipolar collimated emission originating from the E nucleus is a conspicuous feature in the [OIII]5007 and Hα reconstructed images, as well as in the V – R color map. In velocity maps some previously undetected kinematical features are detected, most notably a sharp velocity gradient (more than 300 km s−1) within 2″ NE of the E nucleus. In addition, in the direct imaging mode a bright optical jet extending ~ 1.2″ S from the E nucleus and a fuzzy blue component 0.8″ W of the W nucleus were seen. Both were also discovered on HST images. Detailed ionization maps reveal individual regions with distinct physical conditions, which constrain the mechanism(s) responsible for the ionization of the gas.

In this communication we summarize the main characteristics of three optical fiber systems, namely HEXAFLEX, HEXAFLEX-II, and 2D-FIS, developed for performing simultaneous bidimensional spectroscopy of extended objects. They have been used at the 4.2m William Herschel (WHT) and the 2.5m Nordic Optical Telescope (NOT), which are sited at the Observatorio del Roque de los Muchachos. These systems have been used to observe the circumnuclear regions of several Seyfert galaxies. They show clear advantages over other instruments based on more classical techniques, at least for these complex objects of small angular size on the sky. Some examples will be given to illustrate this.

The integral field spectrograph TIGER, in operation at CFHT since a few years, has been successfully used on a large variety of astrophysical objects, ranging from the planet Mars to distant radio-galaxies and quasars. This review discussed the peculiarities of the TIGER design and gives the main characteristics of the instrument. Two examples of scientific applications are presented to highlight the new possibilities offered by integral field spectrography. Finally the OASIS project dedicated to the CFHT adaptive optics bonnette is briefly presented.

The distant radiogalaxies recently discovered at the most remote distances (z≥3.5) are among the best cosmological targets. However so various features caracterize these galaxies (red stellar energy distribution, huge emission lines, high density of galaxy companions, alignment of ultraviolet and radio axes, large degree of polarisation) that their structures are not simple to understand. Stellar populations will only become the best indicators of evolution of galaxies if these structures are clearly understood from a two-dimension spectroscopy on each image point. The integral field spectrograph TIGER is a unique instrument at the CFHT to give details on the nature and velocities of the various components of distant radiogalaxies.We present the observations with TIGER of an intermediate-redshift galaxy 3C435A (z=0.471) (Rocca-Volmerange et al, 1994). The two nebular lines [OII], [OIII] and the largely extended stellar continua are observable, allowing to date galaxy with the help of our evolution model. The present and past star formation activities and the origin of alignment will be thus analysed in terms of galaxy evolution.

Three quasars, Ton 616, 4C 37.43 and PKS 2251+113 (Stockton and MacKenty 1987) were observed in 1992 at the 3.6 m CFH telescope with the Integral Field Spectrograph TIGER (Courtès et al. 1987, Pécontal 1991) under subarcsecond seeing (0.5 - 0.7”). The spatial sampling was 0.39” in a field 7 by 7 ”, and the spectral resolution 8 ÅFWHM in the Hβ - [OIII]λ 5007 wavelength region (in the rest frame of the objects). The scaling is 4.5, 5.9 and 5.3 kpc.arcsec−1 for Ton 616, 4C 37.43 and PKS 2251+113 respectively (H0 = 75 km.s−1.Mpc−1). The data were reduced with the software developed at Observatoire de Lyon by Rousset, Bacon and Pécontal (Rousset 1992). A detailed account of our results is reported in Durret et al. 1994.

3D spectrography of the inner regions of NGC 1275 has been performed using the integral field spectrograph TIGER. It revealed an association between star clusters and some line emitting gas components, likely to be filaments material. This may indicates that the clusters originate from star formation in the cooling flow

Kinematic investigations of the central (10″×10″) regions of the Seyfert galaxies NGC 4151 and Mkn 573 on the 6-m telescope with 3D-spectroscopy methods are presented.

First attempts to get spectra from extended areas were in the middle of 80-th, using fibers techniques: DensePack (Barden, Scott, 1986), SILFID (Vanderriest and Lemonnier, 1988). Bundle of fibers were put at the focus of the telescope and the other ends of fibers rearranged to produce a long slit of the spectrograph.

Another method of bidimensional spectroscopy, not using optical fibers, was proposed by Prof. G. Courtes (Courtes et al, 1988). He recommended to put behind the telescope focal plane a bidimensional array of microlenses and to project on it an enlarged image. The lens array separates continuous input image and forms an array of micro-pupils that are images of the main mirror illuminating each lens. They create an input image for a classical spectrograph instead of a normal slit. Using of square lenses allows to achieve correct data sampling, and such scheme is ideal for spectrophotometry, allowing integration of total energy from the observed sky area.

We used the integral field TIGER to map the intensity ratios of emission lines and the velocity field over the narrow emission line of a few nearby Seyfert galaxies. Our aim is to study the impact of nuclear activity on galaxies, which will hopefully help us to probe the central engine. We present here some results for two objects: M 51 and NGC 5929.

Using the multi-pupil spectrophotometer of the 6-m telescope, five new chemically distinct galactic nuclei are found.

Degradation of images of astronomical objects during observations with large optical telescope may be described as combination of atmosphere turbulence on a time scale shorter than some tenths of a second and random fluctuation of object’s position due to telescope and observer’s guiding errors, bending of construction under external factors (wind, etc.). Special investigations on the 6-meter telescope (Balega, 1989) showed, that the peak frequency of such low-frequency fluctuations is located near 1 Hz.

The method of Time Resolving Image Mode, developed by J.-L.Nieto et al (1987) for post-detection improvement of angular resolution at CFHT, showed that, even in places with excellent quality of atmosphere, the resolution of large telescope may be increased by 20-30% only, although powerful methods of image recentering and frames selection were performed. Moreover, such method of data processing may be applied to relatively bright objects only. For 6-meter telescope, resolution improvement would be useless at all due to smaller Fried parameter and larger main mirror.

The nuclear region of the NGC 4258 was observed at the 6m Telescope using an integral field spectrograph. Monochromatic maps in Ha and [NII] 6548/6583 Ålines were constructed from the data. Based on monochromatic maps and a velocity field with spatial sampling 0.6 arcsec, and the data published by Courtes et al., (1993) and Cecil et al., (1993) data, we tried to reconstruct the structure of the outflow.

We conducted an observational program using the TIGER integral field spectrograph to study the dynamical structure of nearby galactic nuclei. We already obtained new original results on three of the best ”Black Holes Candidates”: M 32, M 31 and M 104. Their nuclei exhibit complex morphologies and unusual dynamical properties such as: asymmetries, anisotropy, triaxiality which would have been impossible to detect with a ”classical“ spectrograph.