This page contains a list of current, upcoming, and ex-IFSs, together with a summary of their characteristics, their advantages and disadvantages. We also link to the instrument home pages and data-reduction resources where available. Note: not all the instruments listed here are open to use by the whole community. Also, please feel free to add yourself to this page.
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Table of Contents
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European Southern Observatory
VLT
VIMOS (Visual and IR Multi-Object Spectrograph)
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VIMOS is a instrument located on the VLT of ESO in Chile. It has various modes, an IFU being one of them. The IFU array is the largest (in terms of spatial coverage) currently available on an 8-m class telescope, and has good blue sensitivity down to ~4000 Å. The main drawbacks of VIMOS are (i) simultaneous sky observations are not possible, so for projects requiring a good sky subtraction a work-around has to be found, (ii) order-contamination from the 2nd, -1st, -2nd and 0th order persists in the low resolution settings (LR[B,R]), and is particularly bad at either end of the spectral range.
It has 2 dedicated pipelines which produce much the same results: the ESO CPL pipeline (which can be run through the data organizer GUI gasgano or ESOrex on the command line), and VIPGI, which works well and allows for more user interaction, but takes longer to get used to.
Our instrument-specific/data reduction help page is here.
FLAMES + Giraffe
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ARGUS is one of the modes available on the extremely multi-function instrument FLAMES. The spectrograph to which it is coupled is called GIRAFFE. Advantages include a good size FoV and access to a good spectrograph with high resolution gratings. As part of the FLAMES fibre positioner, 14 fibres are available for simultaneous sky observations. Each is individually positionable anywhere within the instrument FoV, thereby allowing for a very robust sky subtraction. The disadvantages are that the spaxel size is relatively large compared to the FoV (meaning that the PSF may not be well sampled), and the Phase II preparation is long and complicated due to the accuracy with which the sky and guide fibres have to be positioned. Currently there are 3 dead fibres in the main array.
Help page for making the Phase II FLD file.
There are 2 dedicated pipelines which produce much the same results: the ESO CPL pipeline (which can be run through the data organizer GUI gasgano or ESOrex on the command line), and girBLDRS (GIRAFFE BaseLine Data Reduction Software from the Geneva group). Our instrument-specific/data reduction help page is here.
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The IFU is deployable Integral Field Unit) of GIRAFFE. For each plate there are 15 IFU units dedicated to objects and another 15 dedicated to sky measurements. In the latter, only the central fibre is present.
Does anyone who has used the IFU mode have something they can add here? Tips and tricks on its use and its data?
Our instrument-specific/data reduction help page is here
SINFONI
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ESO provides a well working pipeline, which as with the other pipelines for the instruments above uses the GUI Gasgano as the front end for the CPL libraries, or alternatively the scriptable ESOrex programme which does the same.
It is easy to follow using the pipeline manual as a starting point, but you may want to read the further details, and set specific parameters when running the pipeline, to improve the sky subtraction, and avoid strong residuals for the sky lines. The ESO pipeline is built on the Spred reduction programme developed by the SINFONI team. This programme is currently not offered directly to the public.
Our instrument-specific/data reduction help page can be found here
Gemini
North and South
GMOS (Gemini Multi-Object Spectrograph)
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The IFU is only one part of the multi-function instrument GMOS. It is available on both Gemini-North in Hawaii and Gemini-South in Chile, and the instruments are of an identical design (the only difference being that nod & shuffle is supported at Gemini-S). The advantages of the GMOS-IFU are that it covers its FoV (which is small, but not tiny) with very good spatial sampling (good enough to comfortably over-sample the PSF), is attached to a stable, medium resolution spectrograph, and allows for simultaneous sky observations (a huge time-saver). Disadvantages are that high resolution gratings are not available, and that the lenslets are hexagonal meaning resampling the data in the x-y plane is unavoidable.
Reduction is carried out fully within the Gemini IRAF package. This works, is well developed, and fairly flexible.
Our instrument-specific/data reduction help page is here.
North only
NIFS (Near-IR Integral Field Spectrograph)
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NIFS is available on Gemini-North in Hawaii. The disadvantage of its small field of view is offset by a good spatial resolution and ability to be coupled to the Altair AO system. Coronographic spectroscopy can also be performed through use of an occulting mask.
Our instrument-specific/data reduction help page is here.
GNIRS (Gemini Near-Infrared Spectrograph)
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The IFU mode for this instrument has been discontinued. Here is an explanation of what it was:
The IFU was an additional optical system, provided for GNIRS by the University of Durham (UK). The IFU takes a rectangular input field, of approximate dimensions 3.3 x 4.8 arcsec, and divides it into 22 slices 0.15 arcsec in width. The IFU optics map the slices of the rectangular field onto the input plane of the spectrograph, aligning the slices more or less along the regular input slit position (the slices are offset from each other by roughly 2 pixels/slice). The optics also change the input scale to 0.12 arcsec/pixel along the slit, and 0.075 arcsec/pixel in the dispersion direction. The IFU was intended to feed the short cameras, and therefore can be operated at a maximum resolution of ~5900.)
Keck
OSIRIS
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OSIRIS home page at Keck. See also the OSIRIS page at UCLA, from which you can obtain the instrument manual and the data reduction pipeline.
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
The OSIRIS IFS was designed for accurate high-spatial-resolution spectroscopy with the Keck AO system. In addition to the IFS, it includes a near-IR imager channel with a 20" field of view and 20 mas pixels. There is a data pipeline for reducing OSIRIS data written in IDL, and an IDL data-cube viewer called Quicklook2, both available from the UCLA site linked above.
There is a pre-existing OSIRIS wiki hosted at UCLA which discusses observing strategies, pipeline tips, etc. Viewing is free, but this wiki requires a password for editing: contact Chris Johnson at the UCLA IR Lab for access.
Our instrument-specific/data reduction help page is here
Subaru
Kyoto 3DII (Kyoto Tridimensional Spectrograph II)
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Kyoto 3DII is a PI instrument of Subaru. This optical spectrograph has four observational modes: IFS with a lenslet array, Fabry-Perot imager, long-slit spectrograph, and filter-imaging modes. Its fine lenslet/pixel sampling of ~0".1 is optimized for good image quality observations. The spectrograph is compact enough to be used also on the UH 88-inch telescope. In this case wider FOVs are emphasized.
Our instrument-specific/data reduction help page is here (in Japanese only).
Observatorio del Roque de los Muchachos (La Palma)
WHT
Integral
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Integral is owned by the IAC and located on the WHT of the ING observatory in the Canary Islands. There are 4 separate IFUs, 3 with different sizes and a 4th with the central fibres blanked out, so acting as a coronograph (a mode that is however rarely used).
Integral is quite a good exploration instrument, as the IFU and grating can be changed easily throughout the night as targets and conditions change. The main drawbacks of Integral are (i) that the spaxels are not contiguous — there are small gaps between the fibres, and this can have repercussions on your flux calibration and PSF coverage; (ii) the focus at the CCD is not completely flat, meaning that the spectral and spatial PSF varies somewhat over the CCD, and (iii) changing grating has to be done physically, not electronically. Data reduction is done with IRAF. An IRAF task based on apall is provided if you ask for it, although you may as well just use apall.
Our instrument-specific/data reduction help page is here
OASIS
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Our instrument-specific/data reduction help page is here
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
SAURON
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Our instrument-specific/data reduction help page is here
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
GHaFaS (Galaxy Hα Fabry-Pérot System)
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Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
McDonald Observatory (Texas, USA)
2.7m Harlan J. Smith Telescope
VIRUS-P
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McDonald Observatory home page
VIRUS-P is the largest field of view IFU in the world. It is the prototype for VIRUS, a massive IFU consisting of a mosaic of 150 units like VIRUS-P to be installed on the HET Telescope during 2011 — see below. The 1/3 fiber filling factor requires 3 dithers to fully sample the FOV. Two gratings are currently available which provide spectral resolutions of 1.6 Å and 4.9 Å, and can be blazed at different angles providing a wavelength coverage of ${\Delta \lambda}$=700 Å and ${\Delta \lambda}$=2200 Å inside the 3500 — 6800 Å range.
VIRUS-W
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VIRUS-W's design is based of VIRUS-P. However its modes of spectral resolution are dedicated to the study of kinematics in low velocity dispersion objects such as disk galaxies or dwarf galaxies. The 1/3 fill factor requires three dithers to sample the field FOV completely. The two resolution modes are realized through two different gratings. The exchange of the gratings is automated and can be done during the night. VIRUS-W is bench mounted and connected via a 25m long fiber bundle to the telescope. It is a visiting instrument at the 2.7m and will eventually be brought back to Germany where it will be installed at the new 2m Fraunhofer Telescope in the Bavarian Alps.
2.2m Univeristy of Hawaii
SNIFS
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SNIFS is a dedicated instrument designed for spectro-photometric observations of nearby supernovae of type Ia for the Nearby Supernova Factory. It has been used to obtain other types of observations as well - the DEEP IMPACT event, core-collapse SN spectroscopy, asteroid spectrophotometry, galaxy spectroscopy, and planet searches.
CFHT (Canada France Hawaii Telescope)
GriF
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Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
Kitt Peak
WIYN (Wisconsin, Indiana, Yale, NOAO) 3.8-m telescope
DensePak
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DensePak home page
DensePak users manual
DensePak is a small fibre-fed IFU. Advantages include a large FoV, large fibres (good for low surface-brightness studies), access to a medium-to-high resolution spectrograph (Hydra), and although is optimised for the red, has acceptable blue sensitivity. Disadvantages include the availability of only 4 dedicated sky fibres, and the lack of lenslets (meaning light is lost through the gaps between the fibres).
Data reduction is performed using the WIYN hydra package within IRAF. The procedure is straightforward and well documented.
Our instrument-specific/data reduction help page is here
SparsePak
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SparsePak, the sister instrument to DensePak, is another small fibre-fed IFU on WIYN. This time the fibres are only tightly packed in the centre, with the rest of the fibres spread out in a sparsely packed array. Since the fibre size is large, the throughput is good, and the total array area is huge, this is an ideal setup for low surface-brightness studies of e.g. nearby galaxy haloes. It is coupled to the same medium-high resolution spectrograph as DensePak (Hydra), and is optimised very much for the red spectral range. Its disadvantages include a lack of full spatial sampling and the lack of lenslets in front of the fibres (only really important for the central tightly packed region).
Data reduction is performed using the WIYN hydra package within IRAF. The procedure is straightforward and well documented.
Our instrument-specific/data reduction help page is here
KPNO 4m
FISICA (Florida Image Slicer for Infrared Cosmology & Astrophysics)
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Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
Calar Alto
3.5-m Telescope
PMAS (Potsdam Multi-Aperture Spectrophotometer)
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PPAK
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PMAS and PPAK are two fibre bundles within the same instrument. PMAS is the standard lens array IFU recommended for high spatial resolution studies, whereas PPAK is the off-axis fibre bundle IFU recommended for large FoV, low surface brightness objects. A nod & shuffle mode is available for very accurate sky subtraction. These are robustly designed instruments (finding the sky location to set your IFU on is way easier than for any other IFU I've used), although for PMAS be aware that changing the grating is not a speedy process. The data is reduced with software provided by the AIP (owners of PMAS) and runs within IDL. Calar Alto is not an observatory with the best weather possible, but it is great to have an IFU that is mounted on a "smaller" telescope, for which certain programmes that will not be accepted for an 8-m class can be run. PPAK is a unique IFU setting of PMAS, unique in being so large, well suited for studies of stellar outflows and clouds in the ISM.
Our instrument-specific/data reduction help page is here
AAO
SPIRAL + AAOmega
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SPIRAL home page
AAO instrument page
Our instrument-specific/data reduction help page is here
Mount Palomar
PIFS
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Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
Observatoire du mont Mégantic 1.6-m
FaNTOmM (Fabry-Perot de Nouvelle Technologie pour l'Observatoire du mont Mégantic)
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FaNTOmM home page (French only)
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
WIRO (Wyoming Infrared Observatory)
WIRO-Spec
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Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
Magellan I
IMACS
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IMACS home page
IMACS-IFU page at Durham
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Our instrument-specific/data reduction help page is here
Apache Point Observatory
ARC 3.5-m Telescope
GIFS
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The Goddard Integral Field Spectrograph (GIFS) is maintained by Michael McElwain, Carol Grady and others from NASA Goddard Space Flight Center. The instrument concept and design was created by Bruce Woodgate. GIFS, formerly known as the Goddard Fabry-Perot Interferometer or GFP, has several modes of operation. The instrument can be configured for direct imaging (400 - 1000nm, with a large collection of filters) with or without a coronagraphic stop (a wedge in the field) and a variety of combinations of grisms and lenslet arrays (7"x7" or 14"x14") for integral field spectrographic operations (480 - 700nm), R=1475 (green grism) or 1823 (red grism). Currently the hi-res grism and Fabry-Perot are unavailable. The instrument is now available to the ARC (Astrophysics Research Consortium) community at large. This telescope is only available to ARC partners.
Does anyone have something to add here: tips and tricks on using this instrument; writing proposals/phaseIIs; or reducing the data. Information that is not in manuals? Post here and we will organise what you have written into the correct format.
Space
Herschel
Herschel was a satellite of the European Space Agency with significant participation from NASA. It operated in the far IR with three instruments: PACS, SPIRE, and HIFI. The former two had photometry and spectroscopy capabilities, and the latter was a spectrograph alone. The PACS spectrograph was an IFS, and the SPIRE and HIFI spectrographs produced 3d datasets when they were operated in their mapping modes.
Herschel was launched in May of 2009 and ceased operations at the end of April 2013. All the data are now public and can be found on the Herschel Science Archive web-site. To reduce the data through one of the various pipelines you can use the interactive Herschel software environment, called HIPE. For each instrument you can find various levels of data, from raw to fully or almost-fully reduced: at Level 2 or higher you have a product that you should be able to do science on. HIPE includes tools to visualise and manipulate Herschel data (of all levels), but since the pipeline end-products are images, cubes, or spectra, they can all also be loaded into any other software (with various degrees of ease or awkwardness) to be analysed.
PACS
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PACS operated in various observing modes, tuned to cover all of the SED or smaller parts of it, to observe a single patch of the sky, a dithered patch of the sky, or to make larger mosaics.
The instrument-specific/data reduction help page is here
SPIRE
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SPIRE operated in various observing modes: low or high spectral resolution; single sky pointing or a raster with sparse to full spatial sampling.
The instrument-specific/data reduction help page is here
Future Instruments
Space
JWST
MIRI is the only instrument for JWST covering the mid-infrared wavelength regime (5-28 micron). It is a multi-mode instrument offering imaging, low-resolution slit spectrscopy and medium-resolution IFU spectroscopy. The IFU uses an image slicer design.
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The MIRI flight hardware is expected to be ready for testing in the autumn of 2010. Launch of JWST is planned for June 2014 (correct as of May 09).
NIRSPEC will also have an IFS mode.
Ground
HET
The HET is planning an IFS called VIRUS (I found this document on it), working in the blue-optical range, which appears to be a combination of a MOS and an IFS; lots of individually small fibres which are arranged in a half-arcmin square (but with significant gaps between the fibres). 145 of these separate units then allows for an extremely large field-of-view coverage. VIRUS is designed to be used in the HETDEX experiment.
ESO — VLT
SPHERE will mount a BIGRE IFS as one of its scientific camera, aimed to the direct detection of exoplanets. SPHERE IFS will prodive 21025 low-resolution (R~30) spectra from 0.95 to 1.7 micron
at very high contrast in a field of view <2.5 arcsec around the target stars. The instrument will be at the Paranal's platform in 2013. See also the Padova page.
KMOS will be a new multi-object IFS (24 deployable IFUs) for the VLT. It will work at 0.8—2.5μm (JHK; at R~3500), and is aimed to be on the telescope in 2010. See also the Durham page.
MUSE is a second generation optical IFS for the VLT developed by CRAL and IRAP (France) AIP and AIG (Germany), ETH (Switzerland), NOVA (Netherlands) and ESO. See also the Lyon page. MUSE has two operating modes: a wide field mode (1x1 arcmin2 FoV, 0.2x0.2 arcsec2 sampling) and a narrow field mode (7.5x7.5 arcsec2 FoV, 0.025x0.025 arcsec2 sampling). It offers a wide simultaneous spectral range (4650-9300 Å and R~3000. MUSE will benefit from the improved spatial resolution given by the Adaptive Optics Facility in development by ESO (Ground layer correction in Wide Field mode and Laser Tomography in Narrow Field mode). The large field of view is provided by 24 IFU identical modules. Each IFU is composed of an advanced image slicer, a spectrograph and a 4kx4k CCD. One single exposure is 400x106pixels. First light is planned late 2012.
ESO — NTT
3D-NTT is planned at the ESO/La Silla NTT 3.5m telescope. It is a tunable filter coupled with a high-resolution Fabry-Perot.
ESO — E-ELT
The E-ELT is ESO's next generation optical/IR telescope. It is currently (Oct 09) in a Phase B study, with first light planned for ~2020. Throughout 2009, 8 instrument Phase A studies were carried out for various instrument concepts, and several of those include IFU spectroscopy modes. Descriptions of these instruments should be read with caution, as the specifications are still very much subject to change, and it is indeed uncertain which will eventually be built. ESO aim to decide on an "instrumentation roadmap" (read: prioritisation and downselect) in the course of 2010.
METIS is the proposed mid-IR instrument for the E-ELT and the only instrument to cover wavelengths longwards of 3 microns. The study is a collaboration of NOVA (Dutch Astronomy Research School), UKATC, MPIA, CEA Saclay and the KU Leuven, and the PI is Bernhard Brandl at Leiden University. METIS will offer a number of observing modes: imaging, including polarimetry and coronagraphy, medium-resolution slit spectroscopy (R ~ 1000-3000) and high-resolution integarl field spectroscopy.
SALT
The RSS will be mounted on SALT and will have a Fabry-Perot imaging spectroscopy mode, working in the optical — see Rangwala, Williams, Pietraszewki & Joseph, astro-ph 2008.
Gran Telescopio Canarias (GTC)
FRIDA will be an image-slicer type IFS working in the IR and will be mounted on the GTC.
MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía).
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MEGARA will be an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4 m. telescope.
MEGARA will be a third generation instrument for GTC, leaded by the University Complutense of Madrid, PI Dr. Armando Gil de Paz, with the collaboration of INAOE, IAA, UPM and comprises 34 researchers from a large number of institutions and companies worldwide.
MEGARA home page http://guaix.fis.ucm.es/megara .
Subaru
FMOS is a MOS being built for Subaru (IR).
Gemini
The Gemini Planet Imager (GPI) will include a lenslet-type IFS as its science camera. The GPI IFS will provide low-resolution (R~40) spectroscopy from 1.0 to 2.3 microns, at very high contrasts for targets <1.2 arcsec from the target star. It will also have a broadband polarimetry mode. The IFS is currently under construction at the UCLA Infrared Lab, and is aimed to be on Gemini South in early 2011. For more information contact James Larkin or Marshall Perrin at UCLA.
ANU 2.3m
Wide Field Spectrograph (WiFeS): integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent throughput, wavelength stability, spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320–950 nm wavelength region. It provides a 25×38 arcsec field with 0.5 arcsec sampling along each of twenty five 38×1 arcsec slitlets. R~3000-7000 with VPH gratings. See Dopita et al., 2007.
