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Grand Canyon 8-m Telescope 1929 3
A World-wide Sample of Instruments 4
Instrumentation Details Instrument name Observing Modes Start of operations Wavelength Coverage Field of View Instrument cost Multiplex gain Spatial [ ]/Spectral resolution # Detectors Detector Format Detector size Buttability Pixel size Pixel scale Electronics Noise Readout Time Dark Current Full well Cost per pixel 5
Wavelength Coverage The great divide between optical and infrared is obvious Basically a bimodal distribution, separated at 1 µm This divide is artificial - it s technology driven, not science driven 180 Instrument 1Number 90 0.1 1 10 100 6
Optical, Near-Infrared, or Mid-Infrared? Currently astronomy is pretty heavily dominated by optical instruments, with ~2 out of 3 instruments using CCDs Percent 70 60 50 40 30 20 10 NOW The next-generation of instruments will consist of nearly equal numbers of optical and NIR instruments Percent 0 50 45 40 35 30 25 20 15 10 5 0 MIR NIR OPT Wavelength Coverage FUTURE MIR NIR OPT Wavelength Coverage 7
What Modes are Most Commonly Used? Spectrometers remain the most popular type of instrument in astronomy (~60%), with imagers a distant second (~25%) Most spectrometers also have an imaging mode, at least to support a target acquisition mode, so imaging systems are important Percent 70 60 50 40 30 20 10 0 Imager Spectrometer Other Among the spectrometers built, not surprisingly the most popular type remains the simple long slit spectrometer 80 70 60 Primary Instrument Modes An equal number of MOS and IFU based systems are either built or planned Given the large multiplex gain of these systems, MOS and IFU spectrometers tend to require the largest focal planes Percent 50 40 30 20 10 0 MOS IFU Long Slit Spectrometer in Use 8
Current Market Share by Various Manufacturers 30 Top histogram shows dominant manufacturers used in various instruments Effectively assumes 1 detector per instrument Others are in many cases are oneoff devices in specialized instruments which together account for ~20% of all instruments Bottom plot tallies all detectors sampled in survey so is a true head count of detectors in use Percent of Instruments Percent of Detectors 25 20 15 10 5 0 50 45 40 35 30 25 20 15 10 5 0 MIT/LL MIT/LL SITe Raytheon Rockwell E2V Manufacturer SITe Raytheon Rockwell E2V Manufacturer Other Other 9
Plate Scale and Field of View Most instruments use (surprisingly) small pixels, most at ~0.1 Lack of >1 pixels is probably due to not sampling small telescopes which often have large fields Clearly a sweet spot in field size of instruments for fields in the 10-100 arcmin 2 range Extremely small fields are pretty much exclusively domain of AO Can t correct over large fields Extremely large fields on the right are mainly due to future ultra wide field instruments involving large CCD focal planes (LSST). Percent Percent 25 20 15 10 5 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Plate Scale (arcsec/pixel) 40 35 30 25 20 15 10 5 0 0.01 0.1 1 10 100 1000 10000 1E+05 1E+06 Field of View (arcmin 2 ) 10
Typical CCD Format, Now and Tomorrow 2x4k building block is, not surprisingly, by far the most popular current CCD format Future planned instruments will baseline 4x4k detectors as much as the more established 2x4k detectors Percent 60 50 40 30 20 10 0 CURRENT 1024x1024 2048x2048 2048x4096 Other Detector Format 77% of future instruments expect to use either 2x4k or 4x4k CCDs Clearly astronomers are eager to use ever larger CCDs Percent 45 40 35 30 25 20 15 10 FUTURE 5 0 1024x1024 2048x2048 2048x4096 4096x4096 Other Detector Format 11
Controller Types Includes all instruments (current and future) in survey SDSU clearly the most commonly used controller in astronomy, with ~1 in 4 controllers being an SDSU system Percent 25 20 15 10 5 Huge range in controllers being used - total of 44 different controllers identified in survey 0 AAO2 ARCON FIERA IRACE SDSU MCE Monsoon MPI This is an area where we would all benefit from an industry standard Manufacturer Closest thing we have is SDSU 12
Instrument Costs Most participants in the survey did not include a cost and, in general, it is difficult to make a detailed apples to apples comparisons due to various assumptions Does cost include labor, overhead, all parts, etc? Instead, have only assessed median costs of current and future instruments to look for basic trends Median Instrument Cost Summary Optical Infrared Current $400,000 $3,750,000 Future $6,600,000 $5,000,000 13
The Galactic Center: Discovery Strip Chart 14
The Galactic Center: Becklin & Neugebauer 1975 15
The Galactic Center: Forrest et al. 1986 16
The Galactic Center: Rigaut et al. 1997 17
The Galactic Center 18
The 25 Year Evolution of the Galactic Center... Our basic understanding of key areas in astronomy is clearly a function of current technology What took us perhaps 25 years to achieve before, may only take ~10 years with the rapid acceleration of technology available to astronomers Advancements in science detectors have made this all possible 25 yrs 19
The ELT s Window on the Universe... ~1
Target: Galactic Cores Objective: Detect signatures of black holes in compact galactic nuclei
Target: First Stars Objective: Morphology, spectra, and luminosity of first luminous objects in the universe
Target: γ-ray bursters Objective: Identify and measure distance & SED of hosts; detect the first GRBs in the universe
Target: Extra-solar planets Objective: Direct imaging and spectroscopy of planetary systems beyond our own
Future Research These facilities will be used to perform enormous surveys to answer major questions in astronomy and fundamental physics, of interest to all of humanity Galaxy Genesis Dark Matter 25
Telescopes 26
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Future Wide Field Facilities - LSST 8.4 Meter Primary Aperture 3.4 M Secondary 5.0 M Tertiary 3.5 degree Field Of View 3 Gigapixel Camera 4k x 4k CCD Baseline 65 cm Diameter Six Filters 30 Second Cadence Highly Dynamic Structure Highly Parallel Readout Accumulated depth ~27 mag. in each filter over 10y Data Storage and Pipelines ~ 18Tb/night! 28
Typical Telescope Focal Configurations
Principal Image Aberrations
Background Noise Sources 31
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Wavefront Errors 34
Coma 35
Lens Convergence Sphere Asphere 36
Instruments 37
The CFHT Legacy Survey MegaPrime is an optical/near IR instrument mounted at the prime focus for 15 to 18 day periods. It consists of the prime focus upper end, a wide field corrector, an image stabilizing unit, the filter assembly, and a focus stage. MegaCam comprises 40 2048 x 4612 CCDs, covering 1 x 1 degree with a plate scale of 0.187 /pixel. The sensors are Marconi (now E2V) CCD42-90 backilluminated devices, 3-side buttable, optimized in the blue. 39
Imaging Spectrograph 40
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First Light Image Direct Imaging Mode 42
Wavefront Propagation
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Wavefront Sensing 45
Detectors 47
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IR Detector Technology
Thermal Emission 57
Infrared Camera 58
Kuipper Airborne Observatory 59
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SIDECAR ASIC 36 channels, each of 10 MHz ADCs with 12 bit resolution Gain adjustment for each channel All bias and clock generation Simple serial interface 16 bit microprocessor for timing and program control Additional array processor for adding, shifting and multiplying on all channels, specifically designed for on ASIC CDS and data processing 61
H4RG MUX and detector, and H1RG detector H4RG MUX H1RG detector H4RG detector 62
SIDECAR ASIC PROGRESS SIDECAR ASIC set up at Rochester Imaging Detector Laboratory All Clocks and Biases probed during power-up and regular operation No Voltages above 3.3 V going to detector SIMPLE INTERFACE HXRG Hirose Connector ASIC USB Cable Computer SIDECAR ASIC attached to an H4RG and connected to DELL Laptop with a USB cable Have tested ASIC over 125 foot fiber/usb cable 63
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