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We have obtained Integral Field Spectroscopy for 23 spiral bulges using INTEGRAL on the William Herschel Telescope and SPIRAL on the Anglo-Australian Telescope. This is the first 2D survey directed solely at the bulges of spiral galaxies. Eleven galaxies of the sample do not have previous measurements of the stellar velocity dispersion (sigma*). These data are designed to complement our Space Telescope Imaging Spectrograph program for estimating black hole masses in the range 10^6-10^8M_sun using gas kinematics from nucleated disks. These observations will serve to derive the stellar dynamical bulge properties using the traditional Mgb and CaII triplets. We use both Cross Correlation and Maximum Penalized Likelihood to determine projected sigma* in these systems and present radial velocity fields, major axis rotation curves, curves of growth and sigma* fields. Using the Cross Correlation to extract the low order 2D stellar dynamics we generally see coherent radial rotation and irregular velocity dispersion fields suggesting that sigma* is a non-trivial parameter to estimate.
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(Abridged) We present observations of the stellar and gas kinematics for a representative sample of 24 Sa galaxies obtained with our custom-built integral-field spectrograph SAURON operating on the William Herschel Telescope. Our maps typically cover the bulge dominated region. We find a significant fraction of kinematically decoupled components (12/24), many of them displaying central velocity dispersion minima. They are mostly aligned and co-rotating with the main body of the galaxies, and are usually associated with dust discs and rings detected in unsharp-masked images. Almost all the galaxies in the sample (22/24) contain significant amounts of ionised gas which, in general, is accompanied by the presence of dust. The kinematics of the ionised gas is consistent with circular rotation in a disc co-rotating with respect to the stars. The distribution of mean misalignments between the stellar and gaseous angular momenta in the sample suggest that the gas has an internal origin. The [OIII]/Hbeta ratio is usually very low, indicative of current star formation, and shows various morphologies (ring-like structures, alignments with dust lanes or amorphous shapes). The star formation rates in the sample are comparable with that of normal disc galaxies. Low gas velocity dispersion values appear to be linked to regions of intense star formation activity. We interpret this result as stars being formed from dynamically cold gas in those regions. In the case of NGC5953, the data suggest that we are witnessing the formation of a kinematically decoupled component from cold gas being acquired during the ongoing interaction with NGC5954.
Integral-field spectroscopy is the most effective method of exploiting the superb image quality of the ESO-VLT, allowing complex astrophysical processes to be probed on the angular scales currently accessible only for imaging data, but with the addition of information in the spectral dimension. We discuss science drivers and requirements for multiple deployable integral fields for spectroscopy in the near-infrared. We then describe a fully modular instrument concept which can achieve such a capability over a 5-10 field with up to 32 deployable integral fields, each fully cryogenic with 1-2.5 micron coverage at a spectral resolution of ~3000, each with a 4 x 4 field of view sampled at 0.2/pixel to take advantage of the best K-band seeing.
We describe a project to study the state of the ISM in ~20 low redshift (z<0.3) QSO host galaxies observed with the PMAS integral field spectrograph. We describe method developement to access the stellar and gas component of the spectrum without the strong nuclear emission to access the host galaxy properties also in the central region. It shows that integral field spectroscopy promises to be very efficient to study the gas distribution and its velocity field, and also spatially resolved stellar population in the host galaxies also of luminous AGN.
In this article we present the integral field spectroscopy (IFS) wiki site, http://ifs.wikidot.com; what the wiki is, our motivation for creating it, and a short introduction to IFS. The IFS wiki is designed to be a central repository of information, tips, codes, tools, references, etc., regarding the whole subject of IFS, which is accessible and editable by the whole community. Currently the wiki contains a broad base of information covering topics from current and future integral field spectrographs, to observing, to data reduction and analysis techniques. We encourage everyone who wants to know more about IFS to look at this web-site, and any question you may have you can post from there. And if you have had any experience with IFS yourself, we encourage you to contribute your knowledge and help the site develop its full potential. Before re-inventing the wheel, consult the wiki...
We present results on integral-field optical spectroscopy of five luminous Blue Compact Dwarf galaxies. The data were obtained using the fiber system INTEGRAL attached at the William Herschel telescope. The galaxies Mrk 370, Mrk 35, Mrk 297, Mrk 314 and III Zw 102 were observed. The central 33x29 regions of the galaxies were mapped with a spatial resolution of 2/spaxel, except for Mrk 314, in which we observed the central 16x12 region with a resolution of 0.9/spaxel$. We use high-resolution optical images to isolate the star-forming knots in the objects; line ratios, electron densities and oxygen abundances in each of these regions are computed. We build continuum and emission-line intensity maps as well as maps of the most relevant line ratios: [OIII]5007Hb, [NII]6584Ha, and HaHb, which allow us to obtain spatial information on the ionization structure and mechanisms. We also derive the gas velocity field from the Ha and [OIII]5007 emission lines. We find that all the five galaxies are in the high end of the metallicity range of Blue Compact Dwarf galaxies, with oxygen abundances varying from Zsun~0.3 to Zsun~1.5. The objects show HII-like ionization in the whole field of view, except the outer regions of IIIZw102 whose large [NII]6584/Ha values suggest the presence of shocks. The five galaxies display inhomogeneous extinction patterns, and three of them have high Ha/Hb ratios, indicative of a large dust content; all galaxies display complex, irregular velocity fields in their inner regions.
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