PalSpec Status Review WITH NOTES RE KECK APPLICATION

PalSpec Status Review

WITH NOTES RE KECK APPLICATIONTerry Herter, Chuck Henderson (Cornell)John Wilson, Mike Skrutskie (Univ. or Virginia)Keith Matthews (Caltech), Jim Howard (Telic)

March 21, 2003


Spectrograph RequirementsOriginal BaselineSimultaneous coverage from 0.80 2.5 mmEmphasis on J, H, and K bandsR ~ 2500 with 30 x 0.9 arcsec slitFor keck R~2500 with slit ~ 15 x 0.45 arcsecSlit viewer with > 2x2 arcmin2 FoVKeck slit viewer ~ 40x40DeliveryDecember 2003For Keck, delivery TBD


WHY DOES IT WORK ON KECKInstrument is being designed to study faint, small (palomar instrument will work at keck with fov reduced by factor of 2


OH Line PositionsPositions of atmosphere airglow (OH) lines vs. wavelength overlaid with atmospheric transmission.


Perspective ViewsCollimatorReimagerGratingSlit viewerFocal Plane


Perspective Views


View with Shell


Prototype Spectrograph CameraPrototype Camera by Jim Howard, Telic Optics


Camera Spot Diagrams


Encircled Energy


Spectrum Layout in Focal PlanePossible array rotation (also rotate slit to keep on columns)


Spectral ResolutionSpectral resolution for 1.0 arcsec slit with 2.78 pixels/arcsecond.


Grating Efficiency


System Throughput* includes primary through detectorAtmospheric transmissionOff the array


Chart1

0.15834679810.17231139090.10000149530.09761621420.07286072590.05700028230.350.35

0.30265195670.25658978320.22816493880.19086983020.12296865460.041644127800

0.06502316640.09142993860.05578069380.08014679850.03880870290.0055082862

Order 3

Order 4

Order 5

Order 6

Order 7

Order 8

Microns

Throughput

Estimated Instrument Throughput

throughput totals

Palomar SpectrographTransmission Calculations

pisco2arotate3bent.zmx

Wavelength (microns)

Order = 3Order = 4Order = 5Order = 6Order = 7Order = 8

2.402.181.871.871.641.461.461.311.191.191.091.011.010.940.870.870.820.77

estimated

throughput

from worksheet 20.160.300.070.170.260.090.100.230.060.100.190.080.070.120.040.060.040.01


2.42.181.871.641.461.311.191.091.010.940.870.820.77

throughput after0.160.300.240.260.190.230.150.190.150.120.100.040.01

summing contributions

from adjacent orders

1.891.89

0.350

1.851.85

0.350

throughput totals

00000000

00000000

000000

Order 3

Order 4

Order 5

Order 6

Order 7

Order 8

Microns

Throughput

Estimated Instrument Throughput


Palomar Spectrograph

Transmission Calculations



Order = 3Order = 4Order = 5Order = 6Order = 7Order = 8

Source2.402.181.871.871.641.461.461.311.191.191.091.011.010.940.870.870.820.77

Element

Primary10.930.920.920.920.910.910.910.900.890.890.880.870.870.860.850.850.840.83

f/16 Secondary10.930.920.920.920.910.910.910.900.890.890.880.890.890.890.880.880.880.87

Dewar Window

surf 1 reflectance20.990.990.990.990.990.990.990.990.990.990.990.990.990.970.950.950.920.90

bulk transmission1.001.001.001.001.001.001.001.001.001.001.001.001.001.001.001.001.001.00


Reimager OAP 1

surf reflectance30.980.980.980.980.980.980.980.980.980.980.980.980.980.980.980.980.980.98

Reimager OAP 2


Collimator


Prism 1 ZnSe




Prism 2 ZnSe




Prism 3 Infrasil




Fold Mirror


Grating


measured efficiency rel alum70.550.950.200.530.880.320.350.800.200.350.770.330.300.710.320.470.630.21

charge for non-littrow (AD=30)80.950.950.950.950.950.950.950.950.950.950.950.950.950.950.950.950.950.95

Camera Lens 1




Camera Lens 2




Camera Lens 3




Camera Lens 4




Camera Lens 5




Camera Lens 6




Camera Lens 7




Detector

sapphire substrate90.930.930.930.930.930.930.930.930.930.930.930.930.930.930.930.930.930.93

quantum efficiency100.600.600.600.600.550.550.550.550.550.550.500.500.500.500.500.500.500.40

Throughput0.160.300.070.170.260.090.100.230.060.100.190.080.070.120.040.060.040.01

Notes:

1. Hal Petrie e-mail dtd 19 Mar 03

2. Estimate 0.99 from 1-2.4 microns, and assume reflectance falls to 0.90 by 0.8 microns

3. Estimate coated silver delivers 0.98 across all wavelengths

4. Thin Film Lab estimate dtd 15 Mar 03 for 28 deg AOI on ZnSe

5. Thin Film Lab estimate dtd 15 Mar 03 for 36 deg AOI on Infrasil

6. Estimate from RGL Catalogue

7. Based on measured littrow reflectances for master grating for orders 4, 6, 7, 8 by RGL, and extrapolation for non-littrow use and missing order mesurements

8. Guess based on Loewen, Neviere & Maystre, Applied Optics, October 1977, p.2711, Fig 8

9. Sapphire from calculating (n-1)^2/(n+1)^2, assume uncoated

10. Estimate from Hawaii-I data found at http://www.mpia-hd.mpg.de/homes/calj/omega2000/newsletter/text.html

P200 reflectivity

P200 Reflectivity

Data from H. Petrie e-mail dtd 19 Mar 03

primary (current estimate)secondary (new coating)secondary (w/ 3 years aging)

0.70.810.90.87

10.870.920.89

1.50.910.950.92

2.50.930.960.93

P200 reflectivity

0

0

0

0

Microns

Reflectance (current estimate)

Primary Reflectance

0

0

0

0

Microns

Reflectance (current estimate)

f/16 Secondary Reflectance

Slit ViewerDesign SpecsOperates at KsImages to ~ 0.14 arcsec/pixGiving 2.4 arcmin FoV => 5.7 sq. arcmin

IntegrationTime (sec)Ks mag (S/N = 5)Number of GalaxiesNumber of Stars117.2311018.41513019.0271


KECK SLIT VIEWERWELL USE 256X256 ARRAY FROM EXISTING IR INSTRUMENTFOV EQUIVALENT TO NIRC FOV (40)


Slit Viewer Detection RateSlit viewer with 2.4 arcmin FoVCounts from Glazebrook et al. 1994, MNRAS, 266, 65.


Spectrograph Line SensitivityAssumptionsS/N = 5, 10 pixels to extract lineSystem throughput = 0.15 in all bandsBetween OH-lines (J,H,K bkgnd = 70, 200, 70 mJy/arcsec2)RN = 5 e-, i(dark) = 0.01 e-/secKECK SHOULD BE 4x BETTERtback = integration time for RN to contribute < 20% to noise.

Flux (10-17 ergs/cm2/s)tbackBand600 sec1800 sec3600 sec(sec)J2.11.10.75410H2.21.20.87170K3.01.71.257


Spectrograph Continuum SensitivityAssumptionsS/N = 5 per resolution elementSystem throughput = 0.15 in all bandsBetween OH-lines (J,H,K bkgnd = 70, 200, 70 mJy/arcsec2)RN = 5 e-, i(dark) = 0.01 e-/secKECK WILL BE 1.5 MAG DEEPER FOR POINT SOURCES

Mag in 1 resolution elementBand600 sec1800 sec3600 secJ19.720.420.8H18.819.519.8K17.718.318.7


PalSpec Status Review WITH NOTES RE KECK APPLICATION

Documents

Transcript of PalSpec Status Review WITH NOTES RE KECK APPLICATION