hifi h eterodyne i nstrument for the f ar i nfrared

HIFI: Submm Workshop,15 Aug, 2006

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HIFI Heterodyne Instrument for the

Far Infrared(The high resolution spectrometer for Herschel)

Michel Fich


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Outline

• HIFI science goals– Water!– Key Projects

• instrument characteristics– the Canadian instrument contribution: the LSU– how to use HIFI – observing modes, integration times

• proposing for HIFI time• support for Canadian astronomers

– the Canadian HIFI team– tools


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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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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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Science with HIFI – Water


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Science with HIFI – Water

SWAS result


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Example – WATER in intermediate mass star forming region

• define intermediate mass as 100 – 1000 Lsun

• spherical core, –1.5 power-law

• assumed water abundance 10-6 H2

– all frozen out at T < 20 K• Monte Carlo solution to radiative transfer (RATRAN)

– run until “lowest” 7 lines in HIFI bands converged with S/N=5

• convolve to HIFI beam appropriate for line frequency– at centre of core

• sample spectra shown for 1000 Lsun (left) and 100 Lsun (right), 100 Msun (top) and 10 Msun (bottom)


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557 GHz ortho (2-1) 61K


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1670 GHz ortho (3-1) 114K


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1661 GHz ortho (4-3) 194K


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1163 GHz ortho (7-6) 305K


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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 – [CII] in distant galaxies


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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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HIFI Instrument Characteristics HIFI Implementation:Heterodyne spectroscopy

– single pixel on the sky– very high spectral resolution

• 7 dual-pol mixer bands– 480-1250 GHz (625-240 m) 5x2

SIS mixers, IF 4-8 GHz

– 1410-1910 GHz(212-157 m; 2x2 HEB mixers, IF 2.4-4.8 GHz

• 14 LO sub-bands– LO source unit in common– LO multiplier chains

• 2 spectrometer systems;– for each polarisation

- auto-correlator spectrometer- acousto-optical spectrometer

HIFI designed for: - Spectral Scans and Spectral line

surveys- Very high spectral resolution- Widest possible coverage in the

unexplored FIR/Submm range

1. Frequency coverage:480 – 1250 GHz (625-240 m)

1410 – 1910 GHz (212-157 m)

2. SensitivityNear-quantum noise limit sensitivity• IF bandwidth/Resolution:

- 4 GHz (in 2 polarisations)- 140 – 280 kHz –0.5 and 1 MHz

3. Calibration Accuracy: 10% baseline; 3% goal


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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)

• Flight Model assembled, undergoing tests. Due to be shipped to SRON first week of Sept. 2006

• the LSU dimensions are 265(H) x 424(L) x 286(W) mm.

The Canadian Hardware Contribution to HIFI


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Latest update LO chain performance:Bands 1-4 by RPG; Bands 5, 6L, 6H by JPL


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HIFI Flight Mixer Performanceat Unit level (open symbols) and

after integration in the FPU


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Band-3 SIS Noise Temperature as function of IF

FM 12, Band6 High, 2005-07-14, S32-82, 4.2K ;LO: 1-- 1.63 THz; 16--1.89 THz

700

900

1100

1300

1500

1700

1900

2100

2300

2500

2700

2.4 2.9 3.4 3.9 4.4 4.9

IF, GHz

DS

B T

r, K

, co

rre

cte

d f

or

op

tic

al l

os

s

FM12-IF-1 Band6H-1.6THzFM12-IF-16 Band6H-1.9THzBand6H-1.8THz

LO:1.63 THz

LO:1.89 THz

Band-6 HEB Noise Temperatureas function of IF

IN HIFI: ONE FREQUENCY Band is working at a time with 2 mixers; • In orthogonal polarisation, also for redundancy.• One LO band, with 2 sub-bands, match the corresponding mixer band


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WBO FM with 1.1 MHz resolution and 4GHz

bandwidth


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HIFI-HRS (auto-correlator) FM Capabilities

2 HRS FM modules


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HIFI Observing Modes

• Dual Beam Switch with internal copper and telescope nod• Position Switch efficiency depending on off-position slew• Frequency Switch with switching LSU• Optimum AOT depends on stability of Telescope-Instrument System


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HIFI Band SensitivitiesBand

1 2 3 4 5 6Frequency Range (GHz) 480-640 640-

800800-960

960-1120

1120-1250

1410-1910

Tsys (K) 160 320 480 730 2000 2500Flux Limit (5, 1hr, R=104) (Jy) 2.3 4.0 5.5 8.0 20 22Flux Limit (5, 1hr, R=104) (mK) 5 9 12 17 43 45Line Flux limit (5,1hr, 104) (10-

18 Wm-2)1.3 3 5 8 24 34

Beamwidth (arcsec) 39 30 25 21 19 13Spectral Resolution (MHz) 0.14 – 0.28 – 1.00


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Estimating integration times

• Time estimate recipe available on web at http://www.sron.rug.nl/hifi_icc/time_estimator.html

• overheads not well known until after launch– slew times: large distances, scanning, small distances (beam-

switching)– pointing/focus/calibration times– re-tuning times: within band and changing bands– data downloads and command uploads

http://www.sron.rug.nl/hifi_icc/time_estimator.html


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Updated Herschel Observing Proposal AO Timeline

• AO KP (GT and OT) issue 1/02/2007• KP GT proposal deadline 5/04/2007• KP GT result official 5/07/2007• KP OT proposal deadline 1/11/2007• KP OT result official 28/02/2008• AO ‘regular’ GT cycle 1 issue 28/02/2008• AO ‘regular’ GT cycle 1 proposal deadline 3/04/2008 • GT result official 5/06/2008• AO OT issue 1/02/2009?

AO = Announcement of Opportunity KP = Key Project

GT = Guaranteed Time OT = Open Time


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Support for Canadian Astronomers

• 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

• Canadian HIFI staff members of HIFI Instrument Control Centre (ICC)

– Science support specialist (University of Waterloo): job available!

– Instrument support specialist (SRON): Kevin Edwards


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Tools for HIFI

• Observing tool is HSPOT (Herschel adaptation of Spitzer SPOT tool)

• Analysis tool is HICLASS (HIFI adaptation of CLASS)• Tools based on Linux and Windows platforms but

Canadian contribution is Mac OSX version – not fully functional because database not available for Macs

• may need to learn some Jython (Java/Python implementation) to write observing scripts, etc.


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Canadian HIFI strategy is to maximize success rate on Open Time (OT) Proposals

• 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 mid-2009

• observing assistance, data analysis advice and software support will be available

http://astro.uwaterloo.ca/HIFI

email: [email protected]

http://astro.uwaterloo.ca/HIFI

mailto:[email protected]

hifi h eterodyne i nstrument for the f ar i nfrared

Documents

hifi waterscience

hifi timesupport

hifi cii

hifi bands

hifi heterodyne instrument

optical spectrometer

intermediate mass star

water abundance