PACS Products Explained

Katrina Exter

KU Leuven

Zoltan Balog

MPIA Heidelberg
Issue User Version HIPE 15
March 2017

Table of Contents

1. Introduction
1.1. The scope
1.2. Other reference material
2. The products in an observation
2.1. Overview
2.2. Navigating an ObservationContext
2.2.1. In HIPE
2.2.2. On disc
2.3. Spectroscopy
2.3.1. Slicing in the pipeline
2.3.2. Level 0 to 1
2.3.3. Level 2 and higher
2.3.4. Missing products
2.3.5. Spectroscopy FITS files on disc
2.3.6. Unchopped range scan obsids: the on- and the off-source obsid
2.4. Photometry
2.4.1. Photometry FITS files on disc
2.5. Tips for reading the Quality and History information
3. Detailed description of the pipeline products
3.1. Introduction
3.2. Spectroscopy
3.2.1. Level 0 to 1: Not yet fully-reduced data
3.2.2. Level 2, 2.5: the final pipeline cubes
3.2.3. Level 2, 2.5, and 3: spectrum tables
3.2.4. Flux calibration for chop-nod drizzled cubes
3.2.5. General comments for all Level 2 science cubes
3.3. Photometry
3.3.1. The science products
4. The Meta Data and FITS Keywords
4.1. Introduction
4.2. Where are the Meta data?
4.3. Meta data and FITS keywords
4.4. Meta data and FITS keywords to help identify spectroscopy slices
5. The Standalone Browse Products
5.1. Introduction
5.2. Photometry
5.3. Spectroscopy
5.3.1. The postcards
5.3.2. Equidistant cubes
5.3.3. Rebinned cube tables
5.3.4. Spectrum tables
6. The recommended products for different science cases
6.1. Introduction
6.2. Spectroscopy
6.2.1. Point sources
6.2.2. Semi-extended sources
6.2.3. Flat extended sources
6.2.4. Other extended sources, crowded fields, off-centred point sources, and semi-extended sources: correcting for the uneven illumination of the PACS IFU
6.3. Photometry

List of Figures

2.1. A spectroscopy ObservationContext, produced by SPG 12.1 and viewed with the Observation Viewer.
2.2. The Levels directory listing in an ObservationContext for a spectroscopy observation produced by SPG 13. Some spectroscopy and photometry observations will also have a Level 2.5 and a Level 3.
2.3. Screengrabs of parts of a spectroscopy ObservationContext stored on disc, having been downloaded from the HSA as a tarball
2.4. Screen-grabs of parts of a spectroscopy ObservationContext stored as a pool on disc
2.5. The level 0 and 0.5 contents for an ObservationContext produced by SPG 13 and higher
2.6. The level 0.5 and 1 contents for an ObservationContext produced by SPG 13 and higher
2.7. The Level 2 contents for a spectroscopy ObservationContext produced by SPG 13 (taken from the same observation as in the figures above). The PacsCubes (HPS3D[R|B]) and the PacsRebinnedCubes (HPS3DR[R|B]) are present for both cameras. The mosaic cubes (drizzled, interpolated, projected) provided for the red and blue differ, because for this observation the mapping was oversampled in the red (4.5" steps in a 2x2 raster) but is considered undersampled in the blue (where steps of 3" in a raster of 3x3 is required). Therefore, projected cubes (HPS3DP[R|B]) are present in both cameras and additionally there is a blue interpolated cube (HPS3DI[R|B]) and a red drizzled cube (HPS3DE[R|B]).
2.8. The Level 2 and 3 contents for a spectroscopy pointed observation produced by SPG 14.
2.9. Screengrabs of parts of a spectroscopy ObservationContext stored on disc, having been downloaded from the HSA as a tarball
2.10. The layers in the level0 and 0.5 product of an ObservationContext (SPG 13)
2.11. The layers in the Level 1 product of an ObservationContext (SPG 13)
2.12. The layers in the Level 2 product of an ObservationContext (SPG 13)
2.13. The layers in the Level 2.5 product of an ObservationContext (SPG 13)
2.14. The layers in the Level 3 product of an ObservationContext (SPG 13)
2.15. Screengrabs of parts of a photometry ObservationContext stored on disc, having been downloaded from the HSA as a tarball
3.1. The datasets in a Frames (SPG 13.0 and higher), and the top part of the Pacs Product Viewer is visible in the Data viewing tab
3.2. The datasets in a PacsCube (SPG 13.0 and higher) and the top part of the Spectrum Explorer is visible in the Data viewing tab
3.3. The datasets in a Level 2 PacsRebinnedCube and a projected cube, taken from an SPG 13 observation. The Spectrum Explorer is open on the cube in Data viewing tab
3.4. The PACS rebinned cube table
3.5. The PacsCentralSpectrum product. Columns are: index, segment, wavelength, band, central spaxel flux and error, "c1" flux and error, "c129" flux and error, and "c9" flux and error. If a column is NaN it means that spectrum is not provided for this type of observation
4.1. Meta data in the Observation viewer

List of Tables

2.1. The contents of Levels 0, 0.5, and 1 of an ObservationContext
2.2. The contents of Levels 2, 2.5, and 3 of an ObservationContext
2.3. The mosaic cubes provided for the different pointing modes of PACS spectroscopy AOTs
2.4. The observing parameters for the different mapping modes. The number and size of the steps need to be fulfilled for an observation to be considered to have the indicated mapping mode, and both keywords for each row must have the indicated value.
2.5. The Meta data and FITS keywords in the Level 2 and higher cubes and tables to inspect to find the observing mode of any observation. The value of the keywords indicate what the specific mode is, i.e. the value of "aot" tells you whether the observation is a line or a range scan
2.6. Spectral range limits: outside of these ranges the data are masked out
2.7. The science-grade PACS spectroscopy products as found in an unpacked tarball gotten from the HSA, for Levels 2, 2.5, and 3. [R|B] and [r|b] indicate a choice between the red and blue camera product/file. The "Directory" is the one in which the FITS file can be found, and in the unpacked directory structure this is located in [obsid]/levelX/HPSXXX, where level"X" and HPS"XXX" are the given in the product context column. The ## in the FITS filenames are a sequence indicator (slice number).
2.8. The PACS spectroscopy standalone browse products as found in an unpacked tarball gotten from the HSA. [R|B] and [r|b] indicate a choice between the red and blue camera product/file. The "Directory" is the one in which the FITS file can be found, and in the unpacked directory structure this is located in [obsid]/browseProduct/HPSXXX, where HPS"XXX" is given in the product context column. The ## in the FITS filenames are a sequence indicator (slice number). Note that the same products are also located in the Level 2/2.5/3 directories.
2.9. The contents of the Levels. [R|B] indicates the red or blue camera
2.10. The PACS photometry products as found in an unpacked tarball gotten from the HSA. [B|R] and [b|r] indicate a choice between the red and blue camera product/file. The "Directory" is the one in which the FITS file can be found, below the directory that is the obsid (1342xxx).
3.1. The contents of PACS pipeline products from Level 2,2.5,3
3.2. The contents of PACS pipeline products
4.1. Meta Data of an ObservationContext
4.2. The Meta data and FITS keywords in the Level 2 and higher cubes and tables to identify what is unique about that particular "slice number". Note that mosaic cubes are the combination of a raster, and hence will not have raster-related keywords.
6.1. The recommended products for different science case and AOT type, for science and/or just for inspection.
6.2. Product name key for Table 6.1.