The Herschel Space Observatory James Di Francesco Herzberg Institute of Astrophysics Whee!

What is Herschel?! 3.5 m diameter space 3.5 m diameter space telescope telescope covers ~  m covers ~  m to be launched by ESA to be launched by ESA in 2008 in th ESA “cornerstone” 4th ESA “cornerstone” missions from Horizon missions from Horizon 2000 plan 2000 plan

Herschel Space Observatory Mirror Assembly Payload Module Service Module Sunshield/shade

Why go into space? Whee!

No atmospheric absorption!! transparent opaque longer wavelengthshorter wavelength submillimetre wavelengths 9 mm 350  m Why go into space?

Herschel Primary Science Goals The cool universe: formation of galaxies and stars, The cool universe: formation of galaxies and stars, ISM physics/chemistry, solar system objects ISM physics/chemistry, solar system objects Herschel’s large aperture, low background and no Herschel’s large aperture, low background and no atmospheric attenuation = high sensitivity atmospheric attenuation = high sensitivity

Herschel in Context: the Past IRAS (1983); o.57 m aperture - all sky survey at 12, 25, 60, 100  m - all sky survey at 12, 25, 60, 100  m - low-res spectroscopy at  m - low-res spectroscopy at  m ISO ( ); o.60 m aperture - photometry at  m - photometry at  m - spectroscopy at  m - spectroscopy at  m KAO ( ); o.91 m aperture - photometry and spectroscopy from = - photometry and spectroscopy from = ~20  m to ~500  m; many instruments ~20  m to ~500  m; many instruments

Herschel in Context: the Present JCMT ( ?); 15 m aperture - photometry at 450 & 850  m (SCUBA2) - photometry at 450 & 850  m (SCUBA2) - spectr’py at 1300, 850, 650, 450  m - spectr’py at 1300, 850, 650, 450  m Spitzer ( ?); 0.85 m aperture - photo’ry at 3.6, 4.5, 5.8, 8.0  m (IRAC), - photo’ry at 3.6, 4.5, 5.8, 8.0  m (IRAC), 24, 70, 160  m (MIPS) 24, 70, 160  m (MIPS) - spectroscopy at 5-38  m (IRS) - spectroscopy at 5-38  m (IRS) ASTRO-F “Akari” ( ?); m - 4-band all-sky survey at  m (FIS) - 4-band all-sky survey at  m (FIS) - imaging/spectr’py at  m (IRC) - imaging/spectr’py at  m (IRC)

Herschel Factoids primary diameter = 3.5 m (large!) primary diameter = 3.5 m (large!) primary material = SiC with a thin primary material = SiC with a thin reflective Al layer + plasil layer reflective Al layer + plasil layer primary WFE < 6% primary WFE < 6% telescope temperature < 90 K telescope temperature < 90 K telescope emissivity < 4% telescope emissivity < 4% abs/rel pointing (68%) < 3.7” / 0.3” abs/rel pointing (68%) < 3.7” / 0.3” science instruments = 3 science instruments = 3 cryostat lifetime > 3.5 years cryostat lifetime > 3.5 years height / width ~ 7.5 m / 4 m height / width ~ 7.5 m / 4 m launch mass = 3200 kg launch mass = 3200 kg power ~ 1500 W power ~ 1500 W cold side hot side

Herschel Science Team at ESTEC on 2006 Feb 1 Spacecraft in structural & thermal test configuration Flight cryostat & parts of flight service module and sunshade installed Whee!

Herschel located in large Lissajous orbit around L2

Herschel Instruments PACS (Photodetector Array Camera and Spectrometer) PACS (Photodetector Array Camera and Spectrometer) SPIRE (Spectral and Photometric Imaging REceiver) SPIRE (Spectral and Photometric Imaging REceiver) HIFI (Heterodyne Instrument for the Far-Infrared) HIFI (Heterodyne Instrument for the Far-Infrared) HIFI PACS SPIRE (EQMs)

Herschel Instruments Photometry/Imaging: 6 bands at  m Photometry/Imaging: 6 bands at  m - PACS: 1.7’ x 3.5’ FOV at 75/110  m and 170  m - PACS: 1.7’ x 3.5’ FOV at 75/110  m and 170  m - SPIRE: 4’ x 8’ FOV at 250, 363 and 517  m - SPIRE: 4’ x 8’ FOV at 250, 363 and 517  m - sensitivity: ~ 1 mJy - 1  - 1 hour (confusion!) - sensitivity: ~ 1 mJy - 1  - 1 hour (confusion!) - no chopping! (no spatial filtering of emission) - no chopping! (no spatial filtering of emission) - angular resolution: ~15” x ( /250  m) - angular resolution: ~15” x ( /250  m) PACSSPIRE

Herschel Instruments Spectroscopy:  m range, R = Spectroscopy:  m range, R = PACS: (grating) 0.8’ FOV at  m, - PACS: (grating) 0.8’ FOV at  m, R = , 5 x 5 spatial x 16 spectral pixels R = , 5 x 5 spatial x 16 spectral pixels - SPIRE: (FTS) 2.6’ FOV at  m, - SPIRE: (FTS) 2.6’ FOV at  m, R = R = HIFI: (heterodyne) 1-pixel FOV at  m and - HIFI: (heterodyne) 1-pixel FOV at  m and  m (no gaps), 4000 channels, R =  m (no gaps), 4000 channels, R = 10 7 PACSSPIRE HIFI

Confusion Limitations CMB exgal bkgrd inter gal’tic dust inter stellar dust Zod- iacal dust Photometric Confusion: Photometric Confusion: - extragalactic confusion: 1 source / 20 beams - extragalactic confusion: 1 source / 20 beams - interstellar dust: cirrus w. powerlaw fluctuations - interstellar dust: cirrus w. powerlaw fluctuations - both improve w. instrumental resolution - both improve w. instrumental resolution - Herschel Confusion Noise Model made by - Herschel Confusion Noise Model made by scaling COBE/ISO data, etc. to PACS/SPIRE bands scaling COBE/ISO data, etc. to PACS/SPIRE bands - determining actual confusion will be major PV activity - determining actual confusion will be major PV activity

Confusion Limitations Spectroscopic Confusion: Spectroscopic Confusion: - “U” lines problematic (but not like OMC1 everywhere) Schilke et al. (2001)

Herschel Timeline: Telescope 2008 August - LAUNCH 2008 August - LAUNCH travel to L2, cooldown travel to L2, cooldown commissioning & performance verification commissioning & performance verification science demonstration + workshop science demonstration + workshop routine science operations (36 months+): routine science operations (36 months+): - ~1000 days of available time ( ) - ~1000 days of available time ( ) - ~1/3 share is Guaranteed Time (GT) to instrument teams - ~1/3 share is Guaranteed Time (GT) to instrument teams - ~2/3 share is Open Time (OT) to world community - ~2/3 share is Open Time (OT) to world community three “Calls for Proposals” (Cycles) foreseen: three “Calls for Proposals” (Cycles) foreseen: - one for Key Projects (>100 hrs), GT & OT - one for Key Projects (>100 hrs), GT & OT - two for regular programs, GT & OT - two for regular programs, GT & OT - in every cycle, GT before OT observations - in every cycle, GT before OT observations } 6 mos.

Herschel Timeline: Data issue AO as late as possible, to maximize timeliness of issue AO as late as possible, to maximize timeliness of scientific programmes and knowledge of instruments scientific programmes and knowledge of instruments 2007 Feb 1: AO for KP proposals issued 2007 Feb 1: AO for KP proposals issued 2007 Apr 5: deadline for GT KP proposals 2007 Apr 5: deadline for GT KP proposals 2007 Jul 5: selection/announcement of GT KP projects 2007 Jul 5: selection/announcement of GT KP projects 2007 Nov 1: deadline for OT KP proposals 2007 Nov 1: deadline for OT KP proposals 2008 Feb 28: selection/announcement of OT KP projects 2008 Feb 28: selection/announcement of OT KP projects 2008 Feb 28: AO for regular GT proposals 2008 Feb 28: AO for regular GT proposals 2008 Apr 3: deadline for GT1 proposals 2008 Apr 3: deadline for GT1 proposals 2008 Jun 5: selection/announcement for GT1 projects 2008 Jun 5: selection/announcement for GT1 projects 2008 August: LAUNCH 2008 August: LAUNCH

Space Astronomy Proposals given limited time (and maybe the promise of extra given limited time (and maybe the promise of extra $$$), space astronomy observing time is often heavily $$$), space astronomy observing time is often heavily oversubscribed (e.g., HST ~ 10!) oversubscribed (e.g., HST ~ 10!) also, relatively few proposal opportunities available also, relatively few proposal opportunities available during lifetime of any given satellite… during lifetime of any given satellite… need to have the highest quality proposals possible, with need to have the highest quality proposals possible, with very little room for largesse (in words or in time!) very little room for largesse (in words or in time!) Google image search for “working hard”

Herschel Pre-Observations space observations require careful planning and program space observations require careful planning and program optimization (mission costs ~1o 6 euros/day!) optimization (mission costs ~1o 6 euros/day!) use “Astronomical Observing Templates” (AOTs) to script a series of “Astronomical Observing Requests” use “Astronomical Observing Templates” (AOTs) to script a series of “Astronomical Observing Requests” (AORs) to execute a program, minimize overheads (AORs) to execute a program, minimize overheads For this, Herschel will use HSPOT, a variant of the Spitzer For this, Herschel will use HSPOT, a variant of the Spitzer Observing Tool (SPOT): extremely easy and fun to use! Observing Tool (SPOT): extremely easy and fun to use! Google image search for “waiting”

Herschel Post-Observations data reduced using single, coherent package: HCSS-DP data reduced using single, coherent package: HCSS-DP Java-based, platform independent - no licences to buy Java-based, platform independent - no licences to buy toolbox to aid interactive analysis (IA) of data toolbox to aid interactive analysis (IA) of data generation of standard data products and relevant quality generation of standard data products and relevant quality information (SPG & QC pipelines) information (SPG & QC pipelines) up to GT groups to provide extra tools up to GT groups to provide extra tools extensive, online & context sensitive documentation extensive, online & context sensitive documentation data will be in FITS format and VO-compliant data will be in FITS format and VO-compliant Google image search for “data reduction”

Summary Herschel will probe a relatively unexplored regime of Herschel will probe a relatively unexplored regime of the EM spectrum at high sensitivities the EM spectrum at high sensitivities data will be very complementary to JCMT, ALMA data will be very complementary to JCMT, ALMA ~2/3 observing time is available to the world community, ~2/3 observing time is available to the world community, For more info see For more info see The end??? Whee! Whee! Whee!