MMT Magellan Infrared Spectrograph MMIRS P I Brian

MMT Magellan Infrared Spectrograph ( MMIRS ) P. I. Brian Mc. Leod Warren R. Brown SAO/Cf. A

Science Drivers – Star formation at high redshift (Erb 2006)

Science Drivers – Brown dwarfs

Multi-Slit Spectrograph Slit Mask Detector (Image from Flamingos)

Basic Operational Modes • Imaging • 6. 9 x 6. 9 arcminute FOV • 0. 202 arcsecond pixels • Y, J, H, Ks wavelength coverage • Spectroscopy • Multi-slit (4′x 7′) or longslit (7′) – J, H, K @ R=3500 – H+K @ R=1300

MMIRS EXTERIOR (2) GUIDER/ WFS TELESCOPE TRUSS ASSEMBLY WITH BOLT INTERFACES TO TELESCOPE & CRYOSTAT SLITMASK SECTION MOS SECTION TRUSS ELECTRONICS RACK TRUSS (2) OPTICS + DETECTOR SECTION DETECTOR PRE-AMP’S

Filter and Grism Wheels Collimator Detector Camera Slit Masks Corrector Optics (warm) Guider/WFS (warm) Dekker LN 2 Tank/ Optical Bench MMIRS INTERIOR

MMIRS OPTICS

MMIRS Field of View Guide camera patrol area D = 14 arcmin A = 50 arcmin 2 ea Guider FOV 80” Imaging field 7 x 7 arcmin Slit masks 4 x 7 arcmin, central 2′x 7′ with full wavelength coverage

Detector Information HAWAII-2 2 k x 2 k Hg. Cd. Te detector • Full well 230, 000 e • Readnoise 16 e- (per pair of reads) • Dark current 0. 05 e-/s/pix at 83 K (temp dependent) • Readout: 32 channels at 180 k. Hz = 0. 7 sec • CMOS device Bad pixels Dark current Flat field

Observed Image Quality 1. 1 pixel FWHM

Imaging Information • • Filters: Y, J, H, Ks Sky background: narrow OH emission and broad H 2 O absorption. Images unguided ~5 sec overhead between exposures, including telescope dither.

Imaging Sensitivity Time (sec) Magnitude of point source (Vega mag) with S/N=10 Y J H Ks 60 19. 6 19. 9 19. 7 18. 7 300 20. 4 20. 8 20. 6 19. 6 3600 21. 8 22. 2 21. 9 21. 0 Time for sky to reach half the linear regime 120 sec 180 sec 30 sec ? sec Total system throughput 0. 20 0. 25 0. 50 0. 40 Exposure Time Calculator: http: //www. cfa. harvard. edu/mmti/mmirs. html

Total System Throughput

Spectroscopic Information • • • Dispersed Spectra: 1400 pixels long Field for complete spectra: 2 x 6. 9 arcmin Full field for spectroscopy: 4 x 6. 9 arcmin 9 slit masks, 7 long slits: 420 x 0. 2, 0. 4, 0. 6, 0. 8, 1. 0, 1. 2, 2. 4” Up to 40 slitlets, of minimum length 10” Grism λ Grooves Resolution Efficiency um lines/mm 0. 4” slit HK 1. 45 -2. 45 80 1300 55 -80% R 3 K 0. 9 -2. 5 62 3500 30 -55% JH 0. 95 -1. 82 94 1300 55 -80%

Spectroscopic Sensitivity Lab test: real spectra. Slit mask Expected S/N per resolution element at R=3000 Spectra Exptime (hr) Mag J Jdark H Hdark K 1 15 118 125 118 165 109 1 17 50 46 36 61 22 2 17 30 66 51 86 31 4 17 71 93 72 122 44 1 19 7 13 7 18 4 2 19 10 19 9 25 5 4 19 15 27 13 35 7

Schedule • March/April 2009 Ø ~1 week engineering run • May/June 2009 Ø ~2 week science “commissioning” • Magellan 2010 (MMIRS and Megacam)

THE WEB SITE http: //www. cfa. harvard. edu/mmti/mmirs. html THE TEAM Principal Investigator: B. Mc. Leod Instrument Scientists: G. Furesz, P. Martini Optical design consultant: H. Epps Co-Investigators: D. Fabricant, J. Geary, S. Kenyon, W. Brown P. Mc. Carthy, E. Persson, S. Eikenberry Project Manager: T. Norton Project Engineer: G. Nystrom Engineering Staff: K. Mc. Cracken, J. Holwell, M. Burke, S. Amato, J. Zajac, H. Bergner, S. Park, E. Hertz Software: D. Curley, M. Conroy, J. Roll, W. Wyatt Technicians: W. Brymer, F. Collette Machinists: K. Bennett, L. Knowles, and the Harvard Model Shop Commissioning Team: A. Seth, W. Brown, D. Fabricant, B. Mc. Leod