3.5arcmin

1.75

arc

min

3.2"x 3.2"on sky

Red photometer32x16 pixels (2x16x16)

Blue photometer64x32 pixels (4x2x16x16)

Integral Integral FieldFieldSpectrometerSpectrometer

Imaging Photometer

For more information please visit: http://pacs.mpe-garching.mpg.de

Simultaneous 57-105 & 105-210 µmspectroscopy.

47”x47” (5x5 pixels) FOV rearrangedvia an image slicer on two 16x25Ge:Ga detector arrays.

λ/Δλ ~ 1500

Sensitivity: ~5x10-18 W/m2 (5σ, 1h)

Simultaneous two-band (same FOV)60-85 µm or 85-130 µm and 130-210 µmimaging.

Two filled bolometer arrays:32x16 and 64x32 pixels

Point source detection limit:~3mJy (5σ , 1h)

PACS is one of three scienceinstruments for ESA’s Herschelmission. It operates either as animaging photometer or an integralfield spectrometer over the spectralband from 57 to 210 µm.

PACS is being designed and built by a consortium of institutes and university departments from acrossEurope under the leadership of Principal Investigator Albrecht Poglitsch located at Max-Planck-Institute forExtraterrestrial Physics, Garching, Germany. Consortium members are: Austria: UVIE; Belgium: IMEC, KUL,CSL; France: CEA, OAMP; Germany: MPE, MPIA; Italy: IFSI, OAP/OAT, OAA/CAISMI, LENS, SISSA; Spain: IAC.

Optical layout of the PACS instrument

Projection of focal plane ontobolometer arrays

6.4"x 6.4"on sky

focal plane

Projection of focal plane ontospectrometer arrays

PACS – A Photodetector Array Camera & Spectrometer for Herschel

Instrument Design

PACS – A Photodetector Array Camera & Spectrometer for Herschel

Scientific Motivations

The opening of the 60-210µm window by PACS to sensitive photometry and spectroscopy at highspatial resolution will address a wide range of key questions of current astrophysics concerning theorigins of stars, planetary systems, galaxies, and the evolution of the Universe.

PACS is also intended to be an important driver for other projects which will explore adjacent spectral regions,such as JWST in the near/mid IR and ALMA in the mm domain.

-Most of the energy released e.g.in starbursts or AGNs is absorbed byinterstellar dust (which preventsobservation at shorter wavelengths)and re-emitted in the far infraredand sub-mm domain.

What is the cosmic history ofstar formation and AGN activity?

How do stars form out of the interstellarmedium?

- Photometric surveysof nearby molecularclouds: search forprotostars

- Photometric mapping andspectroscopy (e.g. CO, H2O,OI) of the circumstellar matterin evolved objects

-Cool, dusty and/or distantobjects have their emissionpeak in the far-IR.

-The far-IR also contains many spectral lines fromatoms, ions and molecules. Largely unaffected byextinction they provide detailed information onUV radiation, density, temperature, velocities andabundances of ionised and neutral components ofinterstellar and circumstellar gas.

Simulated deep PACS survey of10-5 sr at 75, 110 and 175 µm(false colors) to a 1σ limit of~0.5 mJy (50h). Deepestsources are at z~3.

- Deep multi-band photometricsurveys and spectroscopy atthe peak of cosmic starformation (z=1...3)

M82 (Subaru/FOCAS) with thePACS spectroscopy FOV overlayed

How does stellar mass loss influence the ISM chemistry?The carbon starY CVn. ISOPHOT90 µm map(Izumiura et al.1996)

Version: 2005-1

- Local galaxies: photo-metric and spectral linemapping for detailed,spatially resolved studiesof star formation ongalactic scales

For more information please visit: http://pacs.mpe-garching.mpg.de

ρ Oph, SCUBA850 µm (Johnstoneet al. 2000)

Some examples:

z = 2 .44