extragalactic science with the herschel space observatory
DESCRIPTION
Extragalactic science with the Herschel Space Observatory. Marc Sauvage CEA/DSM/DAPNIA Service d'Astrophysique UMR AIM. The Herschel Space Observatory. A European Space Agency (ESA) mission with a NASA participation. 3.5 m , passively cooled ( 80 K ) telescope in space. - PowerPoint PPT PresentationTRANSCRIPT
Extragalactic science with the Herschel Space
Observatory
Marc SauvageCEA/DSM/DAPNIA
Service d'Astrophysique
UMR AIM
The Herschel Space Observatory
•A European Space Agency (ESA) mission with a NASA participation.
•3.5 m, passively cooled (80 K) telescope in space.
•Located at the L2 Lagrange point of the earth-sun system.
•Operating in the Far-Infrared to Submillimeter range (60-700 µm).
•Cryogenically and actively cooled instruments (detector temperature < 1 K).
•3.5 years nominal lifetime.•OfficialLaunchDate: August 2007.
Herschel’s science objective in a nutshell
Turn a nice and simple grey-body curve into a complicated mess of broad solid-state features underlying a forest of lines…
More seriously
Observe star-forming galaxies in a range where they emit most of their flux, taking advantage of the redshift
Herschel's payloadHerschel will cover the FIR-Submm with three instruments:
HIFIHigh resolution
heterodyne spectrometer
Wavelength coverage: 157-625 µmSingle Beam 12-40”High spectral resolution (up to 107)
Limited capacities for extragalactic science
Herschel's payloadHerschel will cover the FIR-Submm with three instruments:
PACSBolometer camera and low resolution photoconductor
spectrometer60-200 µm
Photometer:3 bands at 75, 110 and 170 µm1.8’x3.5’ fully sample field of viewBeam size 6”, 8” and 12”Spectrometer:Imaging provided through image slicer0.8’x0.8’R=1000-2000
Herschel's payloadHerschel will cover the FIR-Submm with three instruments:
SPIREBolometer camera and fourier transform low
resolution spectrometer200-600 µm
Photometer:3 bands simultaneously at 250, 360 and 520 µm4’x8’ field of view (not fully sampled)Beam size 18”, 25”, 36”Spectrometer:200-670 µm2.6’ circular field of view (not fully sampled)R=20->1000 (FTS)
Extragalactic Science with Herschel
Note: Herschel was built to make surveys but, galaxy deep surveys are not the only kind of surveys…
>1/3 of the time will be dedicated to Galactic star formation.
SPIRE & PACS will be the instruments of choice for distant or faint extragalactic objects
Sensitivities as of almost today:
SPIRE PS imaging 3-10 mJy 5 1hr (obs. mode dependent, but all three bands)
PACS PS imaging 3 mJy 5 1hr (two bands simultaneously)
Confusion will be the main limitation of extragalactic science with Herschel
Observing with Herschel
This will be a déjà-vu situation (Herschel is borrowing a lot from Spitzer)
Four program categories:•Garanteed Time (32%)
• Key programs• Regular projects
•Open Time (68%)• Key programs• Regular projects
• L-21m: Key Programs GT submitted
• L-18: Key Programs GT published• L-15: Key Programs OT submitted• L-12: Key Programs OT published• L-9: cycle 1 GT submitted• L-6: cycle 1 GT published• L: Launch• L+9: cycle 1 OT submitted• L+12: cycle 1 OT published• L+21: cycle 2 GT submitted• L+24: cycle 2 GT published• L+27: cycle 2 OT submitted• L+30: cycle 2 OT published• L+42: nominal end of mission
Science timeline
Current situation
Instrument Consortia have prepared a relatively detailed version of their Key Programs (but these over-use the available time).Still to be done is the negotiation between consortia regarding the program contents (competition on GT is not allowed)
•Spectral survey of starburst and AGNs•Photometric survey of the local volume•Photometric survey of active galaxies•Imaging and spectral study of nearby
galaxies•Imaging and spectral study of dwarf
galaxies•Galaxy deep surveys:
• Cosmic IR background• Evolution of the star formation rate and IR luminosity• Environment effects• AGN contribution• Extreme galaxies at very high redshifts
Th
e P
rogra
ms
Contributing to the Herschel Surveys
For most of the surveys objective, the guaranteed time available is not sufficient.
Open time key programs will be necessary to reach these objectives.
• Build your own consortium (in the spirit of the Spitzer Legacy Programs).
• Join existing initiatives and for this contact Steve Eales ([email protected]) or visit http://astronomy.sussex.ac.uk/~sjo/extrahot/