HIFI: Submm Workshop,

1
HIFI Heterodyne
Instrument for the Far Infrared (The high
resolution spectrometer for Herschel)
Michel Fich
2
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

3
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

4
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

5
Science with HIFI Water
6
Science with HIFI Water
SWAS result
7
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 lt 20 K
• Monte Carlo solution to radiative transfer
  (RATRAN)
• run until lowest 7 lines in HIFI bands
  converged with S/N5
• 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)

8
557 GHz ortho (2-1) 61K
9
1670 GHz ortho (3-1) 114K
10
1661 GHz ortho (4-3) 194K
11
1163 GHz ortho (7-6) 305K
12
Molecular Lines visible with HIFI
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
13
Science with HIFI CII in distant galaxies
14
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

15
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 mm) 5x2 SIS mixers,
• IF 4-8 GHz
• 1410-1910 GHz(212-157 mm 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
• Frequency coverage
• 480 1250 GHz (625-240 ?m)
• 1410 1910 GHz (212-157 ?m)
• 2. Sensitivity
• Near-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

16
HIFI Design block diagram
17
HIFI Local Oscillator Source Unit (LSU)
The Canadian Hardware Contribution to HIFI

• 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.

18
Latest update LO chain performanceBands 1-4 by
RPG Bands 5, 6L, 6H by JPL
19
HIFI Flight Mixer Performanceat Unit level (open
symbols) and after integration in the FPU
20
Band-3 SIS Noise Temperature as function of IF
Band-6 HEB Noise Temperature as 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

21
WBO FM with 1.1 MHz resolution and 4GHz bandwidth
22
HIFI-HRS (auto-correlator) FM Capabilities
2 HRS FM modules
23
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

24
HIFI Band Sensitivities
25
Estimating integration times

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

26
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

27
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

28
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.

29

• 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 hifi_at_astro.uwaterloo.ca