Multi-IFU spectroscopy on the LBT Andreas Kelz, Astrophysikalisches Institut Potsdam 2nd Gen Science with the LBT workshop, Ringeberg,

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July D- and fiber-spectroscopy projects at AIP PMAS MUSE VIRUS STELLA & 3.5m CA 8m VLT 9m HET 6dF/RAVE

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 IFU parameter space Kelz, et al Note: one PPak fiber collects twice the light at the 3.5m CA than a VIMOS spaxel at VLT.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 PMAS PMAS: Roth, Kelz, et al., 2005, PASP 117, 620 Lens-array-IFU: 256 spectra, 8“ to 16“ FoV, spectrophotometry options: + nod & shuffle, + Fabry-Perot Etalon + polarimetry PPak-IFU: Fiberbundle, 382 spectra, wide FoV: 74“ x 64“ + simul. calibrat. PPak: Kelz, Verheijen, et al., 2006, PASP, 118, 129 PMAS features 2 IFUs and a spectrograph corrected from nm

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 PPak-IFULARR-IFU vs. FoV: 74“ “ 36 sky fibers 15 calib. fibers Kelz, Verheijen et al Sanchez et al Advantage: coarse (>seeing) sampling allows large field-of-views, which is well suited for extended, low surfaces brightness, complex structures (e.g. galaxies, mergers, nebulae, jets, etc.)

A. Kelz: Multi-IFUSpectroscopy on LBT, Ringberg workshop, 18. July mm CaF2 / Quarz lenses nm wavelength range PMAS spectrograph

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Science example with the PPak-IFU: the Disk Mass Project P. I. Marc Verheijen Right: UGC 463: re-constructed from the PMAS data cube between nm, 1.35“/pixel. Left: POSS image for comparison. Note, that despite the coarse sampling the basic morphology is reconstructed well. using E3D Aim: to measure the velocity distributions of face-on spirals to constrain dark matter contribution.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Advantage: Spatial binning 99 x 108 arcsec HST/WFPC-2 NGC3982 gaining S/N in particular for the fainter outer parts of galaxies by spatial binning of spaxels in azimuth. Credit: M. Verheijen, Kapteyn Institute, Groningen PPak-FoV 74 x 65 arcsec

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Science example: clusters, gravitational lenses 6 hours integration with PPak Lambda: nm de-blended to 1“/pixel 3 hrs HST image (re-sampled to seeing conditions) Sanchez & Cardiel et al 2007 Abell2218

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Advantage: multi-plex information 3 dither pointings yielded 993 spectra 455 monochromatic plus various polychromatic images Sanchez & Cardiel et al 2007

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Science example: large fields – mapping the Orion nebula Sanchez et al Line ratio and abundance maps 7.5 arcmin spaxel (spectra)

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Science example: Luminosity Function of Ly  galaxies Peter Schuecker (MPE) Ralf Bender (USM/MPE) Ulrich Hopp (USM/MPE) Ralf Köhler (USM) Karl Gebhard (UT) Gary Hill (UT) Philipp McQueen (UT) Matthias Steinmetz (AIP) Peter Weilbacher (AIP) Joris Gerssen (AIP) -> Baryon oscillations (HETDEX)

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Astronet Infrastructure Roadmap Ground-based, Small Scale: Wide-Field, Multiplexed Spectrograph. There is an extremely strong scientific case for the development of such an instrument which could be placed at one of a number of existing 8-10m class telescopes (see Section 4.3.2). Such a project was therefore given high scientific priority. The term “wide-field” here means a FOV of at least 1.5 degrees (goal 3 degrees) in order to provide simultaneous spectroscopic observations of thousands of objects over a FOV matched to the scientific requirements, comparable to that envisaged for the next generation wide field imagers, e.g. the LSST. The primary science drivers are the determination of the equation of state of Dark Energy, the study of stellar populations over a large fraction of the history of the Universe, and the study of the structure and formation of the Galaxy and Local Group by determining in a quantitative manner the kinematical and chemical signatures of the different stellar components.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 IFU capabilities at 8-10m VLT: VIMOS-IFU, SINFONI, FLAMES-IF (in operation) KMOS, MUSE, SPHERE (2nd Generation) Gemini: GMOS Keck: OSIRIS GTC:FRIDA, SIDE LBT: (… but all have relatively small fields, e.g. MUSE has 90,000 spaxels but 1‘ x 1‘ FoV …)

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Multi-IFUs NGC 6946, LBC PPak-style IFU‘s in dense configuration

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Multi-IFU Spectrograph for LBT-Gregorian LBT Gregorian station: usable FoV: 10‘ (evt. up to 24‘ ?) F/15 beam + focal red. to ~F/5 7 deployable IFUs each IFU: - ~ fibers - 1/3 fill factor - size of ~1.5 arcmin total no. of fibers: ~ ‘ 60‘‘-90‘‘

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Example: Stellar populations M101 (10‘ x 10‘), each IFU: 90‘‘ x 90‘‘

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Example: Galaxies & Mergers M51 (10‘ x 10‘), each IFU: 90‘‘ x 90‘‘

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Example: Galaxy clusters, gravitational lenses,... Abell1185 (10‘ x 10‘), each IFU: 90‘‘ x 90‘‘ the deployable IFUs can be set on different targets. field #1 field #2

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 VIRUS-IFU: layout –IFU format: hexagonal packed –Dense-pack design with 1/3 fill factor –3 dither exp. to fill the field – fibers / IFU –Fiber core diameters: microns –Step-index quartz broadband multimode fibers –Mapping from IFU to slit: either row by row or random VIRUS P.I. G.Hill, McDonald Obs.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 VIRUS-IFU input head design –Small mount design allows ¼ packing fraction –Precision mount with capillary tubing or precision mask to set matrix (design and manufacture at AIP) 6 mm 11.5 mm

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 VIRUS bundles development Prototype at AIPCommercial built fiber-bundle Prototpye development and R&D with industrial partners.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Fiber bundle developments at AIP Built and under development at AIP: PPak, VIRUS-P1, VIRUS-P2, …, V-Wendelstein

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July fixed central IFU and 8 deployable IFUs using R-  or x-y positioners with a densest IFU fill factor of ¼ advantage: relative „simple“ simulataneous positioning, medium- sized units allow industrial replication at affordable prices. 8 positioners with R-  stages (or x-y stages) IFU placement

VIRUS IFU-Spectrograph l Modified replicated integral field spectrographs (VIRUS-type) –Inexpensive fiber-fed unit IFS –Each with ~250 fibers. –Visible wavelength coverage VIRUS Prototype VIRUS design by: P. MacQueen McDonald Observatory

IFU-Spectrograph placement at LBT IFUs and positioner at direct Gregorian focal station - less complex than prime focus, - place stages & bundles in AGW-type ring structure Spectrograph placement a)at Gregorian station but with grav. stable mount (issues: size, weight, space) b)on the ground (issues: fiber length and effects due to bending, location) c)use MODS (but off-telescope) © McDonald Observatory

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 Further options … - use extended FoV (up to 24‘ ?) at Gregorian focus with/without a corrector lens (vignetting, PSF) ? - option to connect IFU fiber bundles to stationary MODS on the ground (fiber length & numbers of fibers, calibration, ADC) ? - IFUs at prime foci (evt. at f/4.5 trapped Cass. Focus) + long fiber lengths (plate scale, space, corrector,… ?) - use of photonic technologies, such as photonic crystal fibers, fiber bragg gratings, arrayed waveguide gratings, miniaturized spectrographs, … - innovation center for fiber-based spectroscopy (innoFSPEC) and Astrophotonic related R&D at AIP.

A. Kelz: Multi-IFU Spectroscopy on LBT, Ringberg workshop, 18. July 2008 About innoFSPEC The Potsdam Center for Fiber-based Spectroscopy and Sensing innoFSPEC is a joint initiative of the Astrophysical Institute Potsdam (AIP) and the University of Potsdam, Dept. Physical Chemistry & Interdisciplinary Photonics Center (UPPC), whose goal is to create a national center of excellence. The primary research fields of innoFSPEC are - Fiber-coupled multichannel spectroscopy (AWG, PCF, FBG, replicable-miniaturized MCS, …) - Optical fiber-based sensing innoFSPEC requested funding for - 2 research groups with 2 associated-professorships - 6 postdocs and 6 PhD student positions - 1 center manager and 1referent assistant - funding for personal, infrastructure, equipment, travel, etc… - in total: 7.7 M€ granted for 5 years ( ) innoFSPEC excellence center