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GHαFaS, a new Fabry-Perot system, is now available at the William Herschel Telescope (WHT). It was mounted, for the first time, at the Nasmyth focus of the 4.2-m WHT on La Palma in 2007 July. Using modern technology, with a spectral resolution of the order R ~ 15,000, and with a seeing-limited spatial resolution, GHαFaS will provide a new look at the Hα-emitting gas over a 4.8' circular field in the nearby universe. Many science programs can be done on a 4.2-m class telescope in world-class seeing conditions with a scanning Fabry-Perot. Not only galaxies but H II regions, planetary nebulae, supernova remnants, and the diffuse interstellar medium are subjects for which unique data can be aquired rapidly. Astronomers from the Laboratoire d'Astrophysique Experimentale (LAE) in Montreal, the Laboratoire d'Astrophysique de Marseille (LAM-OAMP), and the Instituto de Astrofisica de Canarias (IAC), have inaugurated GHαFaS by studying in detail the dynamics of some nearby spiral galaxies. A robust set of state-of-the-art tools for reducing and analyzing the data cubes obtained with GHαFaS has also been developed.

We present observations of the nearby barred starburst galaxy, M83 (NGC5236), with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William Herschel Telescope on La Palma. The unprecedented high resolution observations, of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the galaxy. The velocity field displays the dominant disk rotation with signatures of gas inflow from kpc scales down to the nuclear regions. At the inner Inner Lindblad Resonance radius of the main bar and centerd at the dynamical center of the main galaxy disk, a nuclear $5.5 (\pm 0.9) \times 10^8 M_\odot$ rapidly rotating disk with scale length of $60 \pm 20$ pc has formed. The nuclear starburst is found in the vicinity as well as inside this nuclear disk, and our observations confirm that gas spirals in from the outer parts to feed the nuclear starburst, giving rise to several star formation events at different epochs, within the central 100 pc radius of M83., Comment: Accepted for publication in ApJ Letters. High-resolution version can be found at http://www.astro.su.se/~kambiz/DOC/paper-M83.pdf

Gas reservoirs, internal or acquired, play an important role in the secular evolution of interacting galaxies, since they are able to enhance/trigger star formation episodes and, probably, feed the activity of active galactic nuclei. Using Fabry‐Perot observations, we have mapped, in the Hα line, the warm (T ≈ 10 4 )g as distribution and the velocity fields of the galaxy members of five interacting, gas-rich galaxy systems. We investigated two M51-like systems (Arp 70 and Arp 74), two systems containing highly disrupted members (WBL 366 and RR 24) and a case of merging in progress (Arp 299, one of the nearest luminous infrared objects). We detected gas motions following the elongated arm/tail of Arp 70b, while in the fainter member of the pair of galaxies, Arp 70a, the gas distribution is off-centred with respect to the stellar isophotes, suggesting an external acquisition. Our kinematic data highlighted noncircular motions in the velocity field of one of the members of Arp 74 (Arp 74a). The two galaxies of the RR 24 system are connected by one tidal tail, through which the kinematically disturbed component RR 24b seems to supply warm gas to RR 24a. In spite of the nearly irregular gas distribution and perturbed morphology, WBL 366a (the star-forming galaxy VV523) and WBL 366b have nearly regular velocity fields. The velocity field in the Arp 299 system is irregular, and gas flow between the two nuclei is detected. The present observations, discussed in the light of model predictions and complementary observations from the literature, suggest that all these systems are still probably in an early phase of the encounter. However, the ionized gas distribution and kinematics are strongly influenced by tidal forces. In particular, cross-fuelling mechanisms between galaxies are in action. In Arp 299 the warm and cold gaseous components show similar kinematic properties, although the cold gas seems to maintain a still better organized motion with respect to the warm gas. Ke yw ords: galaxies: general ‐ galaxies: interactions ‐ galaxies: kinematics and dynamics.

We present the results of imaging and scanning Fabry-Perot interferometry of the cometary nebula GM 3-12 (RNO 124) and Herbig-Haro object HH 376A. The nebula is cone-shaped with the star IRAS 20359+6745 at the apex, straight walls and two probable helical arms. HH 376A is the bow shock structure in the collimated high velocity flow, directed by the axis of the cone nebula, with shock velocity about 70-80 km s - 1 . The spatial and kinematical separation between bow shock and Mach disk in HH 376A was not detected, which makes this object similar to HH 111. The Ha profiles in the vicinity of the source are double peaked. The high velocity component can be attributed to the collimated flow.

We present a completely new technique to read out the CCD matrix that can achieve much lower noise than classical techniques used since the 1970s. This technique is based on digital analysis of the CCD's output signal instead of analog filtering coupled to an original filtering method. Despite several attempts carried out in the past to implement digital correlated double sampling, this is the first time that a radical improvement in readout noise performance is shown. This is highly interesting for low light level conditions, where the detector works in the readout‐noise regime and not in the photon‐noise regime. This is particularly the case when carrying out medium‐ to high‐resolution spectroscopy or multiplex (scanning) observations.

Shells are interpreted as debris from interaction/acquisition episodes that occur in a galaxy. We present a study of the warm (T≈ 104 K) gas component in a sample of five shell galaxies belonging to the Malin & Carter compilation. Hα observations have been obtained at the ESO 3.6-m telescope equipped with a CIGALE scanning Fabry–Perot interferometer coupled with a new IPCS camera. Most of our sample galaxies show disturbed/irregular gaseous velocity fields. The gas distribution in NGC 7070A and 7135 shows elongated, asymmetric structure relative to the stellar body. The continuum and line maps for ESO 2400100 show a double nucleus. The nuclei are slightly off-centre with respect to the barycentre of the pair, a deformation that cannot arise from projection effects and that suggests a strong on-going tidal interaction. Kinematics of the stellar and gas component derived for NGC 1553 are similar, although the gas component shows evidence for non-circular motion. In most of our objects the gas and the stellar kinematics appear decoupled, but no rings of gas nor diffuse gas shells are detected. If shell galaxies form through an acquisition/merging event, the general hypothesis according to which the gas in Es is accreted from outside the galaxy is further supported by these data. We speculate concerning shell galaxy evolution using additional information coming from studies of line-strength indices.

International audience; We present Fabry Perot observations of galaxies in five Hickson Compact Groups: HCG 10, HCG 19, HCG 87, HCG 91 and HCG 96. We observed a total of 15 galaxies and we have detected ionized gas for 13 of them. We were able to derive 2D velocity, monochromatic, continuum maps and rotation curves for the 13 objects. Almost all galaxies in this study are late-type systems; only HCG 19a is an elliptical galaxy. We can see a trend of kinematic evolution within a group and among different groups - from strongly interacting systems to galaxies with no signs of interaction - HCG 10 exhibits at least one galaxy strongly disturbed; HCG 19 seems to be quite evolved; HCG 87 does not show any sign of merging but a possible gas exchange between two galaxies; HCG 91 could be accreting a new intruder; HCG 96 exhibits past and present interactions.

A third-generation image photon-counting system (IPCS) camera is presented, based on a GaAs photocathode that can achieve a quantum efficiency of up to 23%, which is comparable to a thick CCD but without readout noise. This system is 10 times more sensitive at Hα than previous photon-counting cameras. In terms of signal-to-noise ratio, the system outperforms CCDs for extremely faint fluxes, including antireflection-coated, low-noise, thin CCDs. This system, with up to 1K × 1K pixels, is one of the largest monolithic IPCSs. A unique cooling system, based on a Ranque-Hilsh vortex tube, is used for this camera. Real-time centering is done by a scalable digital signal processor board. Astrophysical projects and preliminary results obtained with this new camera coupled with a scanning Fabry-Perot interferometer at the Cassegrain focus of the 3.6 m ESO telescope, the 1.93 m Observatoire de Haute Provence telescope, and the 1.6 m Observatoire du Mont Megantic telescope are presented.

[EN] The MOSCAB experiment (Materia OSCura A Bolle) uses the Geyser technique for dark matter search. The results of the first 0.5 kg mass prototype detector using superheated C3F8 liquid were very encouraging, achieving a 5 keV nuclear recoil threshold with high insensitivity to gamma radiation. Additionally, the technique seems to be easily scalable to higher masses for both in terms of complexity and costs, resulting in a very competitive technique for direct dark matter search, especially for the spin dependent case. Here, we report as well in the construction and commissioning of the big detector of 40 kg at the Milano-Bicocca University. The detector, the calibration tests and the evaluation of the background will be presented. Once demonstrated the functionality of the detector, it will be operated at the Gran Sasso National Laboratory in 2015., We acknowledge the financial support of the Spanish Ministerio de Ciencia e Innovación (MICINN) and Ministerio de Economía y Competitividad (MINECO), Grants FPA2012-37528-C02-02, and Consolider MultiDark CSD2009-00064, and of the Generalitat Valenciana, Grants ACOMP/2014/153 and PrometeoII/2014/079.

The H$\alpha$ velocity fields of a sample of six luminous blue compact galaxies (BCGs) and two companions have been obtained by observations with a scanning Fabry-Perot interferometer. The Fabry-Perot images, velocity fields and rotations curves have been presented in a previous paper (Paper I). In general, the velocity fields are irregular and often contain secondary dynamical components, but display overall rotation. The two companions have more regular velocity fields and rotation curves. In this article we analyse the velocity fields and dynamics together with the morphology of the studied BCGs, and present detailed mass models. In addition, we model the stellar mass content by means of multicolour surface photometry and spectral evolutionary synthesis analysis. By comparison of the masses of stars and those derived from the rotation curve, we show that about half of the galaxies cannot be supported by rotation alone. The morphology and dynamics of the BCGs suggest that the starburst activity in these galaxies are most likely triggered by mergers involving gas-rich dwarf galaxies and/or massive gas clouds., Comment: Accepted for publication in A&A. 22 pages, 13 figures (Grey-scale figures have slightly reduced resolution)

We present observations of Hα emission of Stephan's Quintet obtained with a scanning Fabry-Perot interferometer and samplings of ~11 km s-1 and ~1''. Our observations show an intragroup arclike feature formed of bright Hα knots and diffuse gas distributed along tidal tails associated with NGC 7318B and possibly also NGC 7318A. New velocities for 23 emitting regions detected along the Hα structure are presented. South of NGC 7318B, along a path covering ~12 h−175 kpc, H II regions with velocities ranging from 5540 to 6700 km s-1 are detected, suggesting that two or more overlapping tidal tails and/or a bow-shock region may have been formed through several interaction events within the group.

The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a 3 dimensional matrix of 900 large area photomultiplier tubes housed in pressure resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the PMT chosen for ANTARES., Comment: 21 pages, 10 figures. To be published in Nuclear Inst. and Methods in Physics Research, A

We report on kinematic observations of Ha emission line from four late-type galaxies of Hickson Compact Group 16 (H16a,b,c and d) obtained with a scanning Fabry-Perot interferometer and samplings of 16 km/s and 1". The velocity fields show kinematic peculiarities for three of the four galaxies: H16b, c and d. Misalignments between the kinematic and photometric axes of gas and stellar components (H16b,c,d), double gas systems (H16c) and severe warping of the kinematic major axis (H16b and c) were some of the peculiarities detected. We conclude that major merger events have taken place in at least two of the galaxies group. H16c and d, based on their significant kinematic peculiarities, their double nuclei and high infrared luminosities. Their Ha gas content is strongly spatially concentred - H16d contains a peculiar bar-like structure confined to the inner $\sim$ 1 h^-1 kpc region. These observations are in agreement with predictions of simulations, namely that the gas flows towards the galaxy nucleus during mergers, forms bars and fuel the central activity. Galaxy H16b, and Sb galaxy, also presents some of the kinematic evidences for past accretion events. Its gas content, however, is very spare, limiting our ability to find other kinematic merging indicators, if they are present. We find that isolated mergers, i.e., they show an anormorphous morphology and no signs of tidal tails. Tidal arms and tails formed during the mergers may have been stripped by the group potential (Barnes & Hernquist 1992) ar alternatively they may have never been formed. Our observations suggest that HCG 16 may be a young compact group in formation throught the merging of close-by objects in a dense environment.

For the last ten years faint ionized gas detec- tion has been carried out for elliptical galaxies with suc- cess. The kinematics is essential to understand galaxy gas origin and fate. Here we present a sample of 11 elliptical and lenticular galaxies observed with the \Cigale" scan- ning Perot-Fabry instrument. For each galaxy monochro- matic and velocity map of ionized gas is presented. Geometrical properties such as viewing angles and axis ratios are also derived from observations. Double gaseous components are found in 3 galaxies of our sample, imply- ing an external origin for at least part of the observed gas.

General ideas, as well as experimental and theoretical efforts concerning the prediction and discovery of new structures in the disks of spiral galaxies – giant anticyclones - are reviewed. A crucial point is the development of a new method to restore the full vector velocity field of the galactic gas from the line-of-sight velocity field. This method can be used to get self-consistent solutions for the following problems: 1) determination of non-circular velocities associated with spiral-vortex structure; 2) determination of fundamental parameters of this structure: pattern speed, corotation radius, location of giant anticyclones; 3) refinement of galactic rotation curves taking into account regular non-circular motion in the spiral density wave, which makes it possible to build more accurate models of the mass distribution in the galaxy; 4) refinement of parameters of the rotating gaseous disk: inclination angle, center of rotation and position angle of the major dynamical axis, systematic velocity. The method is demonstrated using the restoration of the velocity field of the galaxy NGC 157 as an example. Results for this and some other spiral galaxies suggest that giant anticyclones are a universal property of galaxies with grand design structure.

We present results from an ongoing survey dedicated to the ionized gas kinematics of Virgo cluster spiral galaxies using Fabry-Perot interferometry. Our goal is to study the environmental effects on galaxy evolution in the Virgo cluster. We report here on the Halpha distribution map and velocity field of NGC 4438, the prototype of an interacting galaxy near the centre of the cluster., Comment: 2 pages, 1 figure, to be published in "IAU Symposium 217, Recycling intergalactic and interstellar matter", ASP Conf Series

During the summer of 1985, the CIGALE Perot-Fabry scanning interferometer of Marseilles Observatory was installed at the prime focus of the 2.6 m telescope of Byurakan Observatory. The long run (two new moons) was successful and gave matereial for numerous publications.

We present the observations of the BCDG IZW18 performed with a Fabry-Perot interferometer at the CFH 3.6 m telescope and with a multi-pupil spectrograph at the SAO (Russia) 6 m telescope. The morphological structure of the galaxy in emission lines and in continuum, the velocity field of the ionized gas, and [OIII]/H β ratio distribution along the NW component have been investigated. Besides the NW and SE HII components, we find a population of small HII regions. Continuum maps show that the peaks of the stellar light distribution are displaced with respect to the emission lines maxima. the velocity field shows peculiar motions superposed on an approximately regular background implying solid body rotation. Emission line profiles exhibit an asymmetric structure, except for the NW compact component. The [OIII]/H β ratio decreases from the center of the NW component to its edge with the gradient of 1.86 kpc−1.

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.

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.

H α-interferometric observations of the HII-regions Sh2-152 and Sh2-153 are carried out with a high resolution (1 pixel=2.13×2.13 arcsec). They confirm the results on the structure of those formations obtained earlier. Individual radial velocities determined in different points for each of these HII-regions show that the inner motions of ionized matter relative to the exciting stars are, in general, of expanding character. It gives ground to assume that in both these star forming regions the dissipation of matter takes place.

International audience; The 3D-NTT is a visible integral field spectro-imager offering two modes. A low resolution mode (R ~ 300 to 6 000) with a large field of view Tunable Filter (17'x17') and a high resolution mode (R ~ 10 000 to 40 000) with a scanning Fabry-Perot (7'x7'). It will be operated as a visitor instrument on the NTT from 2009. Two large programmes will be led: "Characterizing the interstellar medium of nearby galaxies with 2D maps of extinction and abundances" (PI M. Marcelin) and "Gas accretion and radiative feedback in the early universe" (PI J. Bland Hawthorn). Both will be mainly based on the Tunable Filter mode. This instrument is being built as a collaborative effort between LAM (Marseille), GEPI (Paris) and LAE (Montreal). The website adress of the instrument is : http://www.astro.umontreal.ca/3DNTT

The galaxy NGC6384 has been observed with an IPCS through H alpha and [NII] narrow-band interference filters for direct imagery with the 2.6 m Byurakan telescope. We studied main physical parameters of identified 98 HII regions, their diameter and luminosity functions, as well [NII]/H alpha ratio distribution. The integrated distribution function of the HII region diameters can be well fitted by the exponential function. The characteristic diameter has the value (Do = 217 pc) predicted for a galaxy of its measured absolute luminosity. The luminosity function of HII regions has double power laws profile with relatively shallow slope at low luminosities (a = - 0.4), an abrupt turnover at log L(H alpha) = 38.75, and sharper slope at higher luminosities (a = - 2.3). Correlation between luminosity and diameter of HII regions confirms that in general they are constant density, radiation-bound systems. [NII]/H alpha ratio data for HII regions show that there is a negative radial gradient of [NII]/H alpha. In the central region of the galaxy, nitrogen abundance is higher than in the periphery. The properties of the HII regions population of this AGN galaxy does not differs significantly from the properties of the HII regions population of the "normal" galaxies. Reexamining the location of the type Ia SN 1971L in the galaxy, we confirm that it lies on the spiral arm at about 8.6" far from the closest HII region #53 (F81). Such a location can be taken as prove that the progenitor of this SN do not belong to an old, evolved stellar population., Comment: 17 pages, 7 figures

We present a new generation photon counting system based on a full software centering system developed at the Observatoire de Marseille. Since the photon counting systems were developed, several improvements have been made on the camera head, whereas centering systems have evolved somewhat slower. The major improvement made on the presented photon counting system is the use of a fast software algorithm for running on a standard PC computer. This system exhibits outstanding photon counting capacity compared to previous hard-wired or DSP-based centering systems, as well as a remarkable cost / performance ratio.

A catalog of ionized gas velocity fields for a sample of 30 spiral and irregular galaxies of the Virgo cluster has been obtained by using three-dimensional optical data. The aim of this survey is to study the influence of high density environments on the gaseous kinematics of local cluster galaxies. Observations of the Halpha line by means of Fabry-Perot interferometry have been performed at the Canada-France-Hawaii, ESO 3.6m, Observatoire de Haute-Provence 1.93m and Observatoire du mont Megantic telescopes at angular and spectral samplings from 0.4" to 1.6" and 7 to 16 km/s. A recently developed, automatic and adaptive spatial binning technique is used to reach a nearly constant signal-to-noise ratio (S/N) over the whole field-of-view, allowing to keep a high spatial resolution in high S/N regions and extend the detection of signal in low S/N regions. This paper is part of a series and presents the integrated emission-line and velocity maps of the galaxies. Both Halpha morphologies and kinematics exhibit signs of perturbations in the form of e.g. external filaments, inner and nuclear spiral- and ring-like structures, inner kinematical twists, kinematical decoupling of a nuclear spiral, streaming motions along spiral arms and misalignment between kinematical and photometric orientation axes., 17 pages, 9 figures, accepted for publication in MNRAS. All high-res. figures are available on http://www.astro.umontreal.ca/fantomm/virgo . High res. versions of the article are available on ftp://ftp.astro.umontreal.ca/outgoing/chemin

We present Fabry-Perot observations obtained in the frame of the GHASP survey (Gassendi HAlpha survey of SPirals). We have derived the Halpha map, the velocity field and the rotation curve for a new set of 44 galaxies. The data presented in this paper are combined with the data published in the three previous papers providing a total number of 85 of the 96 galaxies observed up to now. This sample of kinematical data has been divided into two groups: isolated (ISO) and softly interacting (SOFT) galaxies. In this paper, the extension of the Halpha discs, the shape of the rotation curves, the kinematical asymmetry and the Tully-Fisher relation have been investigated for both ISO and SOFT galaxies. The Halpha extension is roughly proportional to R25 for ISO as well as for SOFT galaxies. The smallest extensions of the ionized disc are found for ISO galaxies. The inner slope of the rotation curves is found to be correlated with the central concentration of light more clearly than with the type or the kinematical asymmetry, for ISO as well as for SOFT galaxies. The outer slope of the rotation curves increases with the type and with the kinematical asymmetry for ISO galaxies but shows no special trend for SOFT galaxies. No decreasing rotation curve is found for SOFT galaxies. The asymmetry of the rotation curves is correlated with the morphological type, the luminosity, the (B-V) colour and the maximal rotational velocity of galaxies. Our results show that the brightest, the most massive and the reddest galaxies, which are fast rotators, are the least asymmetric, meaning that they are the most efficient with which to average the mass distribution on the whole disc. Asymmetry in the rotation curves seems to be linked with local star formation, betraying disturbances of the gravitational potential. The Tully-Fisher relation has a smaller slope for ISO than for SOFT galaxies.

New Halpha emission-line observations of the Virgo cluster galaxy NGC 4438 are presented. Fabry-Perot interferometry data at an effective angular resolution of ~2" are used to map the kinematics of the ionized gas in the galaxy. For the first time we obtain a velocity field covering a large area in NGC 4438, much larger than that deduced from previous HI and CO maps. The kinematics of the extended, low surface brightness Halpha filaments to the West of the galactic disk is discussed. We report on the discovery of a northern Halpha structure which is clumpier than the other filaments. Evidence for multiple spectral components through the data-cube are presented in a nuclear shell and in the approaching half of the disk. The role of VCC 1040, a dwarf elliptical galaxy located to the South of NGC 4438, is presented to investigate the origin of a small-scale stellar tail of NGC 4438. It could be due to a minor tidal interaction between the two galaxies., 11 pages, 11 figures, accepted for publication in A&A. To obtain a higher resolution version, go to ftp://ftp.astro.umontreal.ca/outgoing/chemin/file1664.ps.gz

We have obtained high spectral resolution (R = 45900) Fabry-Perot velocity maps of the Hickson Compact Group HCG 31 in order to revisit the important problem of the merger nature of the central object A+C and to derive the internal kinematics of the candidate tidal dwarf galaxies in this group. Our main findings are: (1) double kinematic components are present throughout the main body of A+C, which strongly suggests that this complex is an ongoing merger (2) regions $A2$ and E, to the east and south of complex A+C, present rotation patterns with velocity amplitudes of $\sim 25 km s^{-1}$ and they counterrotate with respect to A+C, (3) region F, which was previously thought to be the best example of a tidal dwarf galaxy in HCG 31, presents no rotation and negligible internal velocity dispersion, as is also the case for region $A1$. HCG 31 presents an undergoing merger in its center (A+C) and it is likely that it has suffered additional perturbations due to interactions with the nearby galaxies B, G and Q., Comment: 5 pages + figures - Accepted to ApJ Letter

We present a third generation Image Photon Counting System (IPCS) based on an GaAs photo cathode that can achieve quantum efficiency up to 28%, comparable to a thick CCD, but without readout noise. This system is 10 times more sensitive at Hα wavelength than previous photon counting cameras. In terms of S/N ratio, the system outperforms the CCD for extremely faint fluxes, including anti-reflective coated low noise thin CCDs.

We present a completely new technique to readout CCDs, which can achieve much lower noise than classical techniques used since the 70’s. This technique is based on digital analysis of the CCD’s output signal instead of analog filtering coupled to an original filtering method. Despite several attempts carried out in the past to implement digital Correlated Double Sampling (CDS), this is the first time that a radical improvement in readout noise performance is shown. Developed with this noise level improvement in mind, the zero noise CCD concept is presented. This is highly interesting for low light level conditions, where the detector works in readout noise regime and not in photon noise regime. This is the case particularly when concerning carrying out medium to high resolution spectroscopy, or multiplex (scanning) observations.

The results of the scientific cooperation between astronomers of the Byurakan and Marseille observatories on the study of diffuse matter in the Galaxy are presented.Hα-emission is discovered in the direction of h and x Per. Fabry-Perot observations of three HII-regions, Sh2-152, 153, and 106, show the expansion of the diffuse matter relative to the exciting stars. In the Sh2-106 region a probable jet is found. It is shown that in star forming regions the diffuse matter takes part in expansion motions together with stars.

We have obtained a Halpha position-velocity cube from Fabry-Perot interferometric observations of the HH 110 flow. We analyze the results in terms of anisotropic wavelet transforms, from which we derive the spatial distribution of the knots as well as their characteristic sizes (along and across the outflow axis). We then study the spatial behaviour of the line width and the central radial velocity. The results are interpreted in terms of a simple ``mean flow+turbulent eddy'' jet/wake model. We find that most of the observed kinematics appear to be a direct result of the mean flow, on which are superposed low amplitude (35 km/s) turbulent velocities., 27 pages, 8 Postscript figures. Astronomical Journal (accepted)

We present a third generation instrument using a photon counting camera (IPCS) based on an GaAs photo cathode that can achieve quantum efficiency up to 28%, comparable to a thick CCD, but without readout noise. This system is 10 times more sensitive at the Hα wavelength than previous Fabry Perot system used at the Observatoire du mont Megantic. In terms of S/N ratio, the system outperforms CCD for extremely faint fluxes, included AR coated low noise thin CCDs. This system offers up to 1k x 1k pixels which is the largest monolithic IPCS. An original cooling system is used for camera based on a Ranque-Hilsh vortex tube. The real-time centering is done by a scalable DSP board. FaNTOmM is the association of a focal reducer (PANORAMIX: the 1.6m mont Megantic OmM telescope focal reducer), a Fabry Perot etalon and an IPCS. Preliminary results obtained with the 1.6m mont Megantic telescope are presented.

We present Halpha emission line velocity fields of two Low Surface Brightness galaxies - UGC 628 and UGC 5005 - obtained using Fabry-Perot interferometry observations at the Canada-France-Hawaii telescope. Our goal is to study the dynamics of Low Surface Brightness galaxies., Comment: 2 pages, 4 figures, to be published in "IAU Symposium 220, Dark matter in galaxies", ASP Conf Series

The survey GHASP (Gassendi HAlpha survey of SPirals) will provide a 3-D sample of about 200 nearby spiral galaxies in the Hα line, using a Fabry-Perot system. The data cubes obtained for each galaxy allow to derive line maps, velocity fields and other moment analysis. This data base will allow the following four key ponts.

Since the beginning of the CCDs, the only readout technique used up to now is the correlated double sampling scheme with bandwidth limitation. We developed a totally new technique based on the real time treatment of the output signal of the CCD by a digital signal processor: this allows complex filtering and better evaluation of the pixel charge. This technique is much more noiseless than the previous one and allows to read CCDs at a much lower readout noise, even without any noise in the near future. This is of prime importance for observations at very faint fluxes, dominated by detector noise and not shot noise. That kind of CCD systems could be used for medium to high resolution (both spatial and spectral) 3D spectroscopy of faint sources, and is unbeatable with scanning instruments such as FTS and Fabry Perot spectrographs. Since 8–10m class telescopes are pushing ground observations to fainter and fainter limits with higher and higher spatial resolution, noiseless detectors will become necessary to push even more away the limits.

The ANTARES collaboration is building a deep sea neutrino telescope in the Mediterranean Sea. This detector will cover a sensitive area of typically 0.1 km-squared and will be equipped with about 1000 optical modules. Each of these optical modules consists of a large area photomultiplier and its associated electronics housed in a pressure resistant glass sphere. The design of the ANTARES optical module, which is a key element of the detector, has been finalized following extensive R & D studies and is reviewed here in detail., 26 pages, 15 figures, to be published in NIM

We analyse the line-of-sight velocity field of ionized gas in the spiral galaxy NGC 157 which has been obtained in the H\alpha emission at the 6m telescope of SAO RAS. The existence of systematic deviations of the observed gas velocities from pure circular motion is shown. A detailed investigation of these deviations is undertaken by applying a Fourier analysis of the azimuthal distributions of the line-of-sight velocities at different distances from the galactic center. As a result of the analysis, all the main parameters of the wave spiral pattern are determined: the corotation radius, the amplitudes and phases of the gas velocity perturbations at different radii, and the velocity of circular rotation of the disk corrected for the velocity perturbations due to spiral arms. At a high confidence level, the presence of the two giant anticyclones in the reference frame rotating with the spiral pattern is shown; their sizes and the localization of their centers are consistent with the results of the analytic theory and of numerical simulations. Besides the anticyclones, the existence of cyclones in residual velocity fields of spiral galaxies is predicted. In the reference frame rotating with the spiral pattern these cyclones have to reveal themselves in galaxies where a radial gradient of azimuthal residual velocity is steeper than that of the rotation velocity (abridged)., Comment: 23 pages including 25 eps-figures. Accepted for publication in A&A

In order to investigate the influence of the environment on the supernova (SN) production we have performed a statistical investigation of the SNe discovered in isolated galaxies, in pairs and in groups of galaxies. 22 SNe in 18 isolated galaxies, 48 SNe in 40 galaxies members of 37 pairs and 211 SNe in 170 galaxies members of 116 groups have been selected and studied. We found that the radial distributions of core-collapse SNe in galaxies located in different environments are similar, and consistent with that reported by Bartunov, Makarova & Tsvetkov (1992). SNe discovered in pairs do not privilege a particular direction with respect to the companion galaxy. Also the azimuthal distributions inside the hosts members of galaxy groups are consistent with being isotropics. The fact that SNe are more frequent in the brighter components of the pairs and groups is expected from the dependence of the SN rates on the galaxy luminosity. There is an indication that the SN rate is higher in galaxy pairs compared with that in groups. This can be related to the enhanced star formation rate in strongly interacting systems. It is concluded that, with the possible exception of strongly interacting system, the parent galaxy environment has no direct influence on the SN production, 10 pages, accepted for publication to MNRAS

We present results from a Fabry-Perot study of the Hα velocity fields and morphologies of a sample of luminous blue compact galaxies. We estimate masses from photometry and kinematics and show that many of these BCGs are not rotationally supported. Mergers or strong interactions appear to be the triggering mechanism of the extreme starbursts seen in these galaxies.

Observations of six luminous blue compact galaxies (BCGs) and two star forming companion galaxies were carried out with the CIGALE scanning Fabry-Perot interferometer attached to the ESO 3.6m telescope on La Silla. The observations were made in the H-alpha emission line which is prominent in BCGs. A velocity sampling of 5 km/s and a pixel size of 0.9 arcseconds were used. In this paper we present the observations and the data together with the velocity fields and the derived rotation curves. In addition we provide rough estimates of the total dynamical mass and of the ionised gas mass for each galaxy. All galaxies display rotation, but while the companion galaxies have regular velocity fields, those of the BCGs are complex and appear perturbed. This is the most extensive study to date of the optical velocity fields of BCGs. The interpretation of these results will be presented in a forthcoming paper (Paper II)., 26 pages, 14 figures. Accepted for publication in A&AS. The paper (with figures in slightly higher resolution) and an electronic table is also available at ftp://ftp.iap.fr/pub/from_users/ostlin/Articles/ . Replaced version, figure captions fixed

The Sc galaxy NGC 6181 was observed at the 6m telescope of SAO RAS with the scanning Perot-Fabry interferometer in the H-alpha emission line and at the 1m telescope of SAO RAS in BVRI broadband filters with CCD. Subtraction of the mean circular rotation curve from the two-dimensional velocity field has revealed a ring-like zone with a diameter about of 2 kpc where strong radial gas motions are present. The form of the ring is almost perfectly circular in the plane of the galaxy. It is located closer to the center than the beginning of the well-defined spiral structure, but outside of the central bulge-dominated region. The detected radial velocity reduced to the plane of the galaxy is about 100 km/sec and probably is azimuthally dependent. The very inner region of the galaxy, r < 3 arcsec or 0.5 kpc, shows a turn of the dynamical major axis by about 30 deg. Central continuum isophotes are also twisted which suggests the presence of small nuclear bar., Latex, 9 pages, 6 Postscript figures, 6 GIF figures (+ Fig2. which must be requested by e-mail from olga@sai.msu.su). Accepted for publication in the Astronomy and Astrophysics Supplement Series

We present detailed velocity field of NGC 1052 in [NII]6583A line obtained with scanning Perot-Fabry. Extended ionized gas was studied by Davies et al. (1986) showing a clear counter-rotation between ionized gas and stars. It is an E4 galaxy type with ‘Boxy’ isophotes (Nieto et al. 1991). Taking benefit from high spectral resolution and 2D mapping of Scanning PF, we have discovered several components in our profiles (Plana 1995). Their study shows two main gaseous components: a first one with a Major Axis at PA=45° and a second one at PA=30°. The ionized gas extension is approximately 40″ for the first component and 20″ for the second. The main component contains 100 times more gas than the second one.

In 1990 we began an Hα survey of the Milky Way and the Magellanic clouds at ESO La Silla with a 36 cm telescope. The main goal of this survey is to study in detail complexes of HII regions, as well as the global spiral structure of our Galaxy.

Scanning Perot-Fabry observations (data-cubes of contiguous sub-angstrom monochromatic images) allow us to isolate line-emission from nearby continuum using a ‘local’ very narrow-band filter, without being troubled by the velocity blurring due to internal kinematics.

The radial velocities of the ionized gas in the double system of galaxies NGC 2535-36 (Arp 82) have been measured with a scanning Perot-Fabry interferometer and a two-dimensional photon counting system (the CIGALE equipment). Some 3200 velocity points cover the whole galaxy and its companion with a spatial resolution of 1″5 and a velocity accuracy better than 19 km s−1. The redshifts are found to be 4095 km s−1 ± 10 km s−1 for NGC 2535 and 4085 km s−1 ± 10 km s−1 for NGC 2536 (heliocentric radial velocities). Assuming a distance of 41 Mpc the masses are found to be around 3 1010 M⊙ for the main galaxy and 109 M⊙ for its companion.

The velocity field of the nearby Seyfert galaxy Markarian 1040 = NGC 931 has been investigated using the CIGALE instrument [1] at the prime focus of the 6-m Telescope. The Hα- image of the galaxy shows a well developed two-armed spiral pattern (Fig.1a) in the extended (size ≈ 55 kpc, assuming Ho=50 km/s Mpc) gaseous disc. In the velocity field two local velocity maxima at a distance of 20″ from the center are evident relative to the systemic velocity of 4930 ± 5 km/s (Fig.1b) which are located nonsymmetrically to the line of nodes. This results in a decrease of the rotation velocity as a function of radius two times faster than keplerian in the interval between 6 and 12 kpc at the Markarian 1040 rotation curve along the line of nodes (Fig.2). The local maximum at 1 kpc is caused by the compact bulge. The analysis of the velocity field shows strong deviations from an azimuthal symmetry in the mentioned distance interval. Velocities are subtracted from the observed radial velocity field according to an azimuthally symmetric rotation curve defined for each distance interval by the amplitude of the sinus-like dependence on the position angle. It has been found that the rotation curve determined in such a way is in agreement with the rotation curve of an exponential disc with a scale length of 7.5 kpc derived from the galaxy photometry in the continuum.

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.