PACS instrument and calibration web pages

Observing with PACS

• The PACS observer's manual PDF (11 Mb)

• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory (1.5 Mb) , Poglitsch et al., 2010, A&A, 518, L2, in-flight scientific capabilities of the PACS instrument.

• PACS fact sheet A quick guide to the PACS instrument.

• Key information of PACS on the NHSC web site.

PACS data processing

• The latest User Release HCSS version for PACS data reduction is HIPE v6.0.3, it can be downloaded from: http://herschel.esac.esa.int/HIPE_download.shtml, it corresponds to HIPE 6.0 build 2055.

• HIPE 6.0 build 2055 comes with the latest calibration tree, that will be downloaded automatically after starting HIPE on your local directory, and can also be found on here.

• The corresponding PACS Data Reduction Guide (PDRG) is PDRG version 6.

• Data reduction scripts are now available in HIPE under the menu: Pipeline --> PACS --> Photometer/Spectrometer

• The Nasa Herschel Science center (NHSC) has also posted some PACS Data Processing Tutorials and made convenient scripts on : PACS Script Downloads Page

PACS calibration

Photometer calibration in scan maps.

• Point Spread Function: PACS Photometer Point Spread function (5.5 M), version 1.01, 3 November 2010. A detailed document of the in-flight observed PSF. The accompanying tarball can be found here (31 Mb).
• Herschel/PACS modelled point spread functions (3.1 Mb) is a related document presenting Zemax modelled point spread functions for both an `ideal' and an 'as built' Herschel telescope model. Tarballs with corresponding broad-band and monochromatic PSFs for these two cases are at http://pacs.ster.kuleuven.ac.be/pubtool/PSF. Since the models do not capture all effects found in the observed PSFs, they are useful only in addition to the observed PSFs but cannot replace them.

• Point-source photometry: PACS uses 5 stars as primary calibrators with fluxes ranging from 0.6 to 15 Jy, plus other fainter stars and asteroids as secondary calibrators. A new responsivity calibration (version) will be deployed on the HCSS 7 track consistent with PICC-ME-TN-033 v1.01 and its associated encircled energy fraction (EEF). It improves the accuracy of photometry to 3% in the blue channel and 5% in the red channel. The new calibration is described in detail in the technical note"PACS photometer point-source flux calibration (3.1 Mb) (PICC-ME-TN-037), version 1.0, 12 April 2011.

• PACS Photometer Passbands and Colour Correction Factors for various source SEDs (2.5 Mb) , PICC-ME-TN-038, version 1.0, 12 April 2011.

• Extended emission photometry: There are two technical reports which assess the extended emission (or surface brightness) measured from PACS data to IRAS and Spitzer/MIPS data:
  • Experiments in photometric measurements of extended sources (3.2 Mb) , SAp-PACS-MS-0718-11, March 18, 2011. This report compares photometry of large extended galaxies (using large apertures) between PACS, IRAS and MIPS.
  • Surface brightness comparison of PACS blue array with IRAS and Spitzer/MIPS images (1 Mb), PICC-NHSC-TN-029, v1.01, 12 April 2011. This report summarizes pixel-to-pixel comparisons between extended emission as measured between PACS, IRAS and MIPS.

• Point-source observations:
  • We refer to : PACS Photometer : chop/nod point-source & mini-scan map AOT release note: (2 Mb) version 2.0, 12 November 2010 . We recommend to use the mini scan-map technique in all science cases related to point-sources, compact sources and also in cases of faint extended emission around point-sources.
  • For a more technical assessment of the original chop/nod mode sensitivity intended for point-sources, we refer to SAp-PACS-MS-0711-09 (5.5 Mb).

PACS spectrometer AOTs

The PACS Spectrometer AOT design and observer's access to instrument observing modes is described in Chapter 6 of the PACS Observer's Manual. Guidelines to find the suitable observing mode and the optimization process of the overall observing strategy for various science cases are explained there. Dedicated documents are also available for each AOTs and their sub-modes in AOT Release Notes:

PACS high-sampling chop/nod mode for Line Spectroscopy and Range Spectroscopy AOTs

• PACS chopped line scan and high-sampling range scan AOT release note (19 Jan 2010)

PACS SED and large range scan mode in Range Spectroscopy AOT

• PACS SED and large range scan AOT release note (10 Mar 2010)

PACS unchopped grating scan mode for Line Spectroscopy and Range Spectroscopy AOTs - 2nd generation observing mode

• Unchopped line scan and unchopped range scan/SED mode release note (10 Sep 2010)

PACS wavelength switching mode for Line Spectroscopy AOT - decommissioned 1st generation observing mode

• PACS wavelength switching AOT release note (20 Jan 2010)

PACS spectrometer calibration

• PACS Spectrometer performance and calibration: This document provides details on the calibration accuracy and the necessary information to optimally interpret PACS spectroscopy observations. New issues of this document will be released with new versions of the pipeline and new versions of the calibration files in the Herschel interactive data analysis system.

• Data processing known issues of standard products: Browse quality Level 2 products are provided in the Herschel Science Archive. This page describes typical problems and caveats the observer needs to be familiar when looking at these preview products. The document refers to the version of data processing pipeline currently being used for processing of incoming Herschel data (version number provided therein).

-- BrunoAltieri - 12 April 2011