CASCA 2001Page 1 of 12 SPIRE: The Spectral and Photometric Imaging Receiver Presentation to CASCA 2001 The SPIRE Team

CASCA 2001Page 2 of 12 The Herschel Space Observatory THE HERSCHEL MISSION: Herschel is a general purpose astronomical observatory to carry out photometry and spectroscopy over the spectral range 80 – 670  m Cornerstone ESA mission UNIQUE FEATURES: Large (3.5m), cold (80K), low-emissivity (4%) telescope Access to poorly-explored spectral range with no atmospheric interference Large amount of high-quality observing time VITAL STATISTICS: Launch: April 2007 on Ariane 5; Lifetime: 4.25 years Orbit: around Sun-Earth L2 point Payload cooling: to 4K using onboard LHe (ISO cryostat technology)

CASCA 2001Page 3 of 12 The Herschel Spacecraft PAYLOAD INSTRUMENTS: Heterodyne Instrument for FIRST (HIFI)  High-resolution spectroscopy over selected spectral bands Photoconductor Array Camera and Spectrometer (PACS)  Imaging photometry and low- resolution spectroscopy,  m Spectral and Photometric Imaging Receiver (SPIRE)  Imaging photometry and low- resolution spectroscopy,  m

CASCA 2001Page 4 of 12 SPIRE Science Objectives PRIMARY OBJECTIVES: The main scientific goals of SPIRE are the investigation of the statistics and physics of galaxy and structure formation at high redshift and the study of the earliest stages of star formation, while the protostar is still coupled to the interstellar medium These studies require the capability to carry out large-area deep photometric imaging surveys at far-infrared and submillimetre wavelengths Survey observations will be followed up with spectroscopy of selected sources SPIRE will exploit the unique advantages of Herschel and will have unmatched sensitivity SECONDARY OBJECTIVES: SPIRE will also be a powerful tool for many other astrophysical studies: giant planets, comets, the galactic interstellar medium, nearby galaxies, ultraluminous infrared galaxies and active galactic nuclei

CASCA 2001Page 5 of 12 Galaxies and Protostars GALAXIES: emit primarily in the far infrared due to reprocessing of stellar UV by interstellar dust; redshifted into submm for z~1-5 determination of bolometric luminosity (star formation rate) requires that submm SED be known PROTOSTARS: cold cloud cores emit primarily in the far infrared and submm bolometric luminosity and temperature can be determined from measurement of the thermal continuum including the peak PACS

CASCA 2001Page 6 of 12 Instrument Summary In order to carry out large-scale photometric surveys and follow-up spectroscopy, SPIRE consists of two separate parts. 3-BAND IMAGING PHOTOMETER: = 250, 350, 500  m; /  ~ 3 4 x 8 arcmin field of view; diffraction-limited beams IMAGING FOURIER TRANSFORM SPECTROMETER: =  m; /  = (variable) 2.6 arcmin field of view Mach-Zehnder configuration with novel broadband beamsplitters DESIGN FEATURES: feedhorn-coupled spider web bolometer detector arrays detector arrays cooled to 0.3 K by 3 He fridge minimal use of mechanisms sensitivity limited by thermal emission from low-emissivity telescope at 80 K

CASCA 2001Page 7 of 12 SPIRE Photometer FIRST focal surface M3 M4 M5 M6 M7 M8 Beam steering mirror Offner relay Dichroics and arrays M9 2-K cold stop Detector array modules 3 He cooler Shutter

CASCA 2001Page 8 of 12 SPIRE Spectrometer Telescope input port Calibrator input port Output port Intensity beam dividers Fore-optics shared with photometer Detector array modules Mirror mechanism

CASCA 2001Page 9 of 12 Mach-Zehnder FTS FEATURES:  Access to two input ports, complementary output ports  Optical amplification of 4  Novel beamsplitters: high and uniform efficiency over broad spectral range  FTS of similar design is being built for use at the JCMT

CASCA 2001Page 10 of 12 The SPIRE Consortium PI: Matt Griffin, QMW, London COUNTRIES: Canada, France, Italy, Spain, Sweden, UK, USA CONSORTIUM INSTITUTES:  Caltech/Jet Propulsion Laboratory, Pasadena, USA  CEA Service d’Astrophysique, Saclay, France  Imperial College, London, UK  Institut d’Astrophysique Spatiale, Orsay, France  Instituto de Astrofisica de Canarias, Tenerife, Spain  Istituto di Fisica dello Spazio Interplanetario, Rome, Italy  Laboratoire d’Astronomie Spatiale, Marseille, France  Mullard Space Science Laboratory, Surrey, UK  NASA Goddard Space Flight Center, Maryland, USA  Observatoire de Paris, Meudon, France  Queen Mary and Westfield College, London, UK  Rutherford Appleton Laboratory, Oxfordshire, UK  UK Astronomy Technology Centre, Edinburgh, UK  Stockholm Observatory, Sweden  Università di Padova, Italy  University of Saskatchewan, Canada

CASCA 2001Page 11 of 12 Canadian Participation in SPIRE AGREED WORK PACKAGES: shutter subsystem, ICC manpower other possibilities are under investigation CANADIAN SPIRE TEAM: Principal Investigator:  G.R. Davis, University of Saskatchewan Co-Investigators:  P.A. Feldman, HIA  M. Halpern, UBC  D.A. Naylor, University of Lethbridge  D. Scott, UBC  C.D. Wilson, McMaster University Project Manager:  D.G. Peterson, CSA Instrumentation Scientist:  J.K. Taylor, University of Saskatchewan

CASCA 2001Page 12 of 12 Shutter Subsystem DESCRIPTION: vane will cover SPIRE entrance aperture to block flux from cryostat surface facing detectors will be coated with high- emissivity material vane temperature will be controllable between 5 and 20K to provide known flux to detectors (heater and temperature monitor) 4-K actuator and position sensor Industrial partner: COM DEV (Courtesy COM DEV)