HIFI: CASCA08, 23 May, 20081 HIFI Heterodyne Instrument for the Far Infrared (The high resolution...
Transcript of HIFI: CASCA08, 23 May, 20081 HIFI Heterodyne Instrument for the Far Infrared (The high resolution...
HIFI: CASCA08, 23 May, 2008 1
HIFI Heterodyne Instrument for the
Far Infrared(The high resolution spectrometer for Herschel)
Michel Fich
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Outline
Herschel- science - the mission
HIFI- the instrument- science- the Canadian HIFI team
• what comes after Herschel?
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Herschel Main Scientific Objectives
Formation and evolution of galaxies and clusters in the early universe Star formation rates, bolometric luminosities, AGN structure Evolution of chemical elements
Formation of stars & planets and physics of the interstellar medium Tracers of structure, kinematics, chemistry in star forming regions Circulation/enrichment of the interstellar medium Astrochemistry – WATER Detailed studies of nearby resolvable galaxies
Cometary, planetary, and satellite atmospheres History of the solar system Pristine material in comets Water activity
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Herschel: The Mission• facility-class far-infrared/submm space observatory
– 1/3 Guaranteed Time, 2/3 Open Time with annual calls for proposals
• 3.5 m Ritchey-Chrétien telescope that will passively cool to around 70K
• have an operational lifetime of at least three years
• incorporates an ISO-type liquid helium cryostat
• launched by an Ariane 5 in late late 2008 (with Planck)
• operate from an orbit around the L2 point in the Sun/Earth system located approximately 1.5 million km away from the Earth in the anti-sunward direction
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Herschel: The Instruments
• SPIRE: simultaneously imaging at 250, 350, 500 μm with 322, 242, and 162 pixels in same 4'x4' FOV or low to medium resolution spectroscopy in 2'x2'
• PACS: spectroscopy with velocity resolution of 100-250 km/s and 1300-3000 km/s coverage or imaging with two 25x16 arrays at 80-130 and 130-210 μm simultaneously
• HIFI: very high spectral resolution heterodyne spectroscopy spanning 480-1250 and 1410-1910 GHz with wide and narrow band spectrometers operating in parallel
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HIFI Design block diagram
Instrument Control Unit
f~1GHz f variable
HRS-vIF processorSub-band division
f~1GHz f variable
HRS-hIF processorSub-band division
f 4 GHz f 1 MHz
WBS-vIF processorSub-band division
f 4 GHz f 1 MHz
WBS-hIF processorSub-band division
fromtelescope
Common OpticsCalibration sourceChopper mechanism7 Mixer Assemblies each with 2 mixersIF amplifiers
FPU
ControlMixer biasAmplifier biasMechanism control
FCU
LOUHousingRadiator7 LO Assemblies with 7x2 LO chains and power amplifiers
LCUControlMultiplier biasPower amplifier
bias
LSUControlMaster oscillatorSynthesizerRef. distribution
spacecraftOBDH
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HIFI Local Oscillator Source Unit (LSU)
• built by COMDEV• performing extremely well in tests
• the LSU dimensions are 265(H) x 424(L) x 286(W) mm.
The Canadian Hardware Contribution to HIFI
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HIFI Core Science
Solar System:• Water in Giant Planets• Chemistry Martian atmosphere
ISM in Galaxies:• Normal galaxies• Physical properties•of star-forming ISM
Dense cores and star-formation:• Dynamics• Role of Water• Disks
ISM in the Milky Way:• Structure• Dynamics (pressure)• Composition (gradients)
Late stages of stellar evolution:• Winds• Shells• Asymmetries• Composition
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Molecular Lines visible with HIFI
H2O 20 lines
O2 15 lines
HDO 40 lines
H218O 24 lines
CO 13 lines
OH 6 lines
OH+ 4 lines
Plus lines ofHD, HD+, H2D, 6LiH, 7LiH, CH, CH+, NH, NH+, NeH+, HF, SH, SH+, HCl, FeH, SiH, SiH+, CH2, NH2, NH3, … plus many lines from larger molecules
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Science with HIFI – Water
SWAS result
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HIFI Key Projects (Guaranteed Time)• water in star forming regions
– low mass: pre-stellar, Class 0, Class 1, outflows– intermediate mass: embedded (led by Doug Johnstone)– high mass: pre-stellar, hot cores, maps– disks– hydrides
• Ori B maps and spectral surveys– Ori KL, Ori-South (led by Rene Plume), bar maps
• warm ISM– PDRs, diffuse, shocks, low-UV, hydrides, C-clusters (Peter Martin on
team)• Solar System
– comets, mars, outer solar system• evolved stars• extragalactic
– galactic centre, star bursts, ultra-luminous, AGNs, Cen A, metal-poor
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Canadian HIFI Steering Committee
• Michel Fich* (University of Waterloo) Canadian Lead Co-Investigator• Doug Johnstone* (NRC/HIA)• Peter Martin* (University of Toronto)• Henry Matthews (NRC/HIA/DAO/DRAO)• Bill McCutcheon (University of British Columbia)• Rene Plume* (University of Calgary)
* “Astronomy Co-Investigator” - member of the international HIFI Science Team
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Canadian HIFI strategy is to maximize success rate on Open Time Proposals
•we expect a call for OT proposals due no sooner than May 2009
•Canadian staff and Science Team members available as a resource to all Canadian astronomers to help with proposals
•Canadian HIFI Workshop for potential users in 2009 (perhaps with CASCA meeting)
•observing assistance, data analysis advice and software support will be available
http://astro.uwaterloo.ca/HIFI
email: [email protected]
Herschel Meeting: 12:00 – 13:30 Friday, Esqumalt Room
What comes after Herschel?
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• cold telescopes (SPICA)• larger telescopes (10 meter diameter)• Interferometers
Join the Far InfraRed Discipline Working Group
(FIRDWG) to learn more!
http://astro.uwaterloo.ca/~firdwgMeeting Thursday after the CASCA Business
Meeting
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The Far-IR Spatial Resolution Gap
~ 0.005 arcsecs with few K sensitivity
~ 10 arcsec with micro-K sensitivity
JWST
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Interferometers: Heterodyne vs. Direct Detection Heterodyne – detect the signals at each antenna and then
combine electronically
Direct Detection – combine beams, then detect signal
• sensitivity• resolution• technology challenges (cost and schedule)
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Based largely on the NASA-sponsored study of theSpace Infrared Interferometric Telescope (SPIRIT), a candidate Origins Probe mission
Based largely on the NASA-sponsored study of theSpace Infrared Interferometric Telescope (SPIRIT), a candidate Origins Probe mission
Dave LeisawitzNASA