PalSpec Status Review1 PalSpec Status Review WITH NOTES RE KECK APPLICATION Terry Herter, Chuck Henderson (Cornell) John Wilson, Mike Skrutskie (Univ. or Virginia) Keith Matthews (Caltech), Jim Howard (Telic) March 21, 2003

PalSpec Status Review2 Spectrograph Requirements Original Baseline –Simultaneous coverage from 0.80 – 2.5  m Emphasis on J, H, and K bands –R ~ 2500 with 30 x 0.9 arcsec slit –For keck R~2500 with slit ~ 15 x 0.45 arcsec –Slit viewer with > 2x2 arcmin 2 FoV –Keck slit viewer ~ 40”x40” Delivery –December 2003 –For Keck, delivery TBD

PalSpec Status Review3 WHY DOES IT WORK ON KECK Instrument is being designed to study faint, small (<~1”) objects, one at a time f number: at palomar 16, keck 16.6 Seeing at keck ~1/2 that at Palomar –=>palomar instrument will work at keck with fov reduced by factor of 2

PalSpec Status Review4 OH Line Positions Positions of atmosphere airglow (OH) lines vs. wavelength overlaid with atmospheric transmission.

PalSpec Status Review5 Perspective Views Collimator Reimager Grating Slit viewer Focal Plane

PalSpec Status Review6 Perspective Views

PalSpec Status Review7 View with Shell

PalSpec Status Review8 6 inches CaF2/CaF2 Infrasil/ZnS/ZnSe ZnSe/ZnSe Asphere Array tilted 1.3 deg Prototype Camera by Jim Howard, Telic Optics Prototype Spectrograph Camera

PalSpec Status Review9 Top/Bottom of 30 arcsec slit Camera Spot Diagrams

PalSpec Status Review10 2 pix radius = 18 micron If 2.78 pix/arcsec (slit width Palomar = 72 Keck = 36 arcsec Encircled Energy

PalSpec Status Review11 Spectrum Layout in Focal Plane Possible array rotation (also rotate slit to keep on columns)

PalSpec Status Review12 Spectral Resolution Spectral resolution for 1.0 arcsec slit with 2.78 pixels/arcsecond.

PalSpec Status Review13 Grating Efficiency

PalSpec Status Review14 * includes primary through detector System Throughput Atmospheric transmission Off the array

PalSpec Status Review15 Slit Viewer Design Specs –Operates at Ks –Images to ~ 0.14 arcsec/pix –Giving 2.4 arcmin FoV => 5.7 sq. arcmin Integration Time (sec) Ks mag (S/N = 5) Number of Galaxies Number of Stars

PalSpec Status Review16 KECK SLIT VIEWER WE’LL USE 256X256 ARRAY FROM EXISTING IR INSTRUMENT FOV EQUIVALENT TO NIRC FOV (40”)

PalSpec Status Review17 Slit Viewer Detection Rate Slit viewer with 2.4 arcmin FoV Counts from Glazebrook et al. 1994, MNRAS, 266, sec 10 sec 30 sec

PalSpec Status Review18 Spectrograph Line Sensitivity Assumptions –S/N = 5, 10 pixels to extract line –System throughput = 0.15 in all bands –Between OH-lines (J,H,K bkgnd = 70, 200, 70  Jy/arcsec 2 ) –RN = 5 e-, i(dark) = 0.01 e-/sec KECK SHOULD BE 4x BETTER Flux ( ergs/cm 2 /s)t back Band600 sec1800 sec3600 sec(sec) J H K t back = integration time for RN to contribute < 20% to noise.

PalSpec Status Review19 Spectrograph Continuum Sensitivity Assumptions –S/N = 5 per resolution element –System throughput = 0.15 in all bands –Between OH-lines (J,H,K bkgnd = 70, 200, 70  Jy/arcsec 2 ) –RN = 5 e-, i(dark) = 0.01 e-/sec KECK WILL BE 1.5 MAG DEEPER FOR POINT SOURCES Mag in 1 resolution element Band600 sec1800 sec3600 sec J H K

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