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HIFI
Heterodyne Instrument for the
Far Infrared
(The high resolution spectrometer for Herschel)
Michel Fich
HIFI: CASCA08, 23 May, 2008
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Outline
 Herschel
- science
- the mission
 HIFI
- the instrument
- science
- the Canadian HIFI team
• what comes after Herschel?
HIFI: CASCA08, 23 May, 2008
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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
HIFI: CASCA08, 23 May, 2008
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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 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
HIFI: CASCA08, 23 May, 2008
late
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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
HIFI: CASCA08, 23 May, 2008
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HIFI Design block diagram
f rom
telescope
LOU
FPU
Housing
Radiator
7 LO Assemblies
with 7x2 LO chains
and power amplifiers
Common Optics
Calibration source
Chopper mechanism
7 M ixer Assemblies
each with 2 mixers
IF amplifiers
LSU
LCU
Control
Control
M aster oscillator M ultiplier bias
Synthesizer
Power amplifier
Ref. distribution
bias
FCU
HRS-v
HRS-h
WBS-v
WBS-h
Control
M ixer bias
Amplifier bias
M echanism control
IF processor
Sub-band division
IF processor
Sub-band division
IF processor
Sub-band division
IF processor
Sub-band division
 f~1GHz
f variable
 f~1GHz
f variable
 f 4 GHz
f 1 M Hz
 f 4 GHz
f 1 M Hz
Instrument Control Unit
spacecraf t
OB DH
HIFI: CASCA08, 23 May, 2008
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HIFI Local Oscillator Source Unit (LSU)
The Canadian Hardware Contribution to HIFI
•
•
built by COMDEV
performing extremely well in tests
• the LSU dimensions are
265(H) x 424(L) x 286(W) mm.
HIFI: CASCA08, 23 May, 2008
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HIFI Core Science
ISM in Galaxies:
• Normal galaxies
• Physical properties
•of star-forming ISM
ISM in the Milky Way:
• Structure
• Dynamics (pressure)
• Composition (gradients)
Dense cores and
star-formation:
• Dynamics
• Role of Water
• Disks
Late stages of
stellar evolution:
• Winds
• Shells
• Asymmetries
• Composition
Solar System:
• Water in Giant
Planets
• Chemistry Martian
atmosphere
HIFI: CASCA08, 23 May, 2008
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Molecular Lines visible with HIFI
H 2O
20 lines
O2
15 lines
HDO
40 lines
H218O
24 lines
CO
13 lines
OH
6 lines
OH+
4 lines
Plus lines of
HD, 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
HIFI: CASCA08, 23 May, 2008
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Science with HIFI – Water
SWAS result
HIFI: CASCA08, 23 May, 2008
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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
HIFI: CASCA08, 23 May, 2008
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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
HIFI: CASCA08, 23 May, 2008
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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
HIFI: CASCA08, 23 May, 2008
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What comes after Herschel?
• cold telescopes (SPICA)
• larger telescopes (10 meter diameter)
• Interferometers
Join the
Far InfraRed Discipline Working Group
(FIRDWG)
to learn more!
http://astro.uwaterloo.ca/~firdwg
Meeting Thursday after the CASCA Business
Meeting
HIFI: CASCA08, 23 May, 2008
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The Far-IR Spatial Resolution Gap
~ 10 arcsec with micro-K
sensitivity
~ 0.005 arcsecs with few K
sensitivity
UofW Astro-lunch
29 Nov. 2006
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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)
UofW Astro-lunch
29 Nov. 2006
16
Dave Leisawitz
NASA
Based largely on the NASA-sponsored study of the
Space Infrared Interferometric Telescope (SPIRIT),
a candidate Origins Probe mission
UofW Astro-lunch
29 Nov. 2006
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