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Find information, examples, FAQs and extensive descriptions of the data, curated by the survey teams.

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The Sydney-AAO Multi-object Integral-field spectrograph puts 13 fused hexabundles, each containing 61 fibres, across a square-degree field of view. SAMI will provide a comprehensive spatially-resolved view of galaxy evolution.
Nov. 10, 2020 by S. Croom
Dec. 14, 2020, 4:13 a.m. L. Cortese

Input, photometric and observational catalogues

Changes from DR2 to DR3

In DR2 and prior we provided the main input catalogue for the GAMA region. For DR3 there are several changes to the input and other related catalogues we are releasing. Specific changes are:

  • Coordinates for both object position and IFU position are now provided in the GAMA catalogue. Galaxy PA is also corrected to the proper on-sky definition of North, through East.

New catalogues releases:

  • Cluster galaxy input catalogue.
  • Catalogues for secondary calibration.
  • Catalogue for filler galaxies.
  • Catalogue of visual morphology
  • Catalogue of multi-Gaussian Expansion photometric fits.
  • Catalogue that contains quality information for all observed cubes.

Below we outline each of the catalogues, but further details can be found in Croom et al (2020). The Data Central schema browser gives descriptions of individual columns in tables.

1. The GAMA input catalogue

The GAMA input catalogue (InputCatGAMADR3) contains all potential targets within the 3 GAMA regions at RA approx 9hr, 12h, 15h and declination 0 degrees. This is based on data from the Galaxy and Mass Assembly (GAMA) Survey, and target selection is described in detail by Bryant et al. (2015) and on the target selection page of the SAMI Data Central documentation.

This catalogue provides basic data for the target objects including coordinates, redshift, magnitude, g-i colour, extinction, effective radius and others. Two sets of coordinates are given, one called (RA_OBJ, DEC_OBJ) are the coordinates of the object. The second set, (RA_IFU,DEC_IFU), are the nominal pointing of the IFU. In most cases these are the same, but in a small number of cases these were offset to allow asymmetric galaxies or close mergers to be fully contained within the field-of-view. Those galaxies with offsets had their BAD_CLASS parameter (see below) set to 5.

The BAD_CLASS parameter flags various problems with the input data, and the definition of these different classes are given in the table below and also in Bryant et al. (2015). Objects with BAD_CLASS = 0, 5 or 8 are potential targets to be observed.

BAD_CLASS value description Observe (Y/N)
0 Object is okay Y
1 Nearby bright star N
2 Target is a star N
3 Subcomponent of a galaxy N
4 Very large low-redshift galaxy N
5 IFU position requires offset Y
6 Poor redshift from input catalogue N
7 Other problems N
8 Smaller galaxy of a close pair of galaxies. Y

2. The clusters input catalogue

We newly release the clusters input catalogue (InputCatClustersDR3) for DR3 which is based on the target selection described on the Data Central target selection page and in Owers et al. (2017). This catalogue contains largely the same parameters as the GAMA catalogue, based either on SDSS or VST/ATLAS photometry. Additional cluster specific parameters are also included in this catalogue, and these include a member/non-member flag, normalized projected clustercentric distances ($R/R_{200}$) and normalized peculiar velocity ($v_{pec}/\sigma_{200}$). Further description of these can be found in Owers et al (2017) and Croom et al. (2020).

3. The filler input catalogue

In some fields (particularly towards the end of the survey) not all hexabundles could be allocated to a target in the main input catalogues (see above). As a result we added extra filler targets. The filler catalogues do not have the large amount of ancillary information contained within the main input catalogues. In most cases just coordinates and redshift, along with a flag indicating the type of filler. The filler object classes are defined by their FILLFLAG parameter. Only a small fraction of these have been observed; see Croom et al. (2020) for details. The filler samples are listed in the table below. $N_{all}$ is the number of potential filler targets and $N_{obs}$ is the number observed (typically a small fraction of the total number).

FILLFLAG Description Nall Nobs
20 Galaxies with 21cm detections from ALFALFA 22 1
30 Galaxies in a close pair with both outside of the SAMI selection 1800 36
40 Galaxies in a close pair with one outside of the SAMI selection 141 1
50 0.12<z<0.15 star forming disks to test weak lensing. 996 13
90 Early cluster galaxy observations that did not meet the final selection limits 21 21

4. The secondary calibration star catalogues

Flux calibration for the DR3 made use of secondary flux standards observed at the same time as the main SAMI galaxy sample. These were selected to be F-dwarfs (largely in the galactic halo) based on photometric color (see Bryant et al. (2015) and Owers et al. (2017) for details). As part of DR3 we release the target list for all these calibration stars (including those that were never observed). Catalogues are named FstarCatGAMA and FstarCatClusters.

5. The observational catalogue

As part of DR3 we provide a catalogue that lists quality information and warning flags for each cube constructed and released. This is contained within catalogue CubeObs. This includes seeing and relative transmission. Where multiple cubes sets have been made for an object, each cube set has a separate entry in the CubeObs catalogue. A parameter ISBEST indicates in the case of repeats which data is considered the best, based on seeing and S/N. Other flags indicate missing data, or value added products, and other calibration of measurement problems or warnings. The catalogue schema browser describes each of these warnings.

6. Visual morphology catalogue

All galaxies observed by SAMI in the main samples have been visually classified by members of the team using RGB composite images from SDSS or VST/ATLAS. The classification scheme is described in detail by Cortese et al. (2016). In summary the scheme was simple, using 4 types: elliptical, S0, early spiral, late spiral. For a small fraction (approximately 5%) no classification could be agreed upon. These visual morphologies are provided in catalogue VisualMorphologyDR3.

7. Multi-Gaussian expansion catalogue

For all galaxies observed in the main GAMA and cluster input catalogues we make photometric measurements using the Multi-Gaussian Expansion algorithm (Emsellem et al. 1994). We make use of the MGEFIT package (Cappellari 2002). This provides measures of effective radius, ellipticity and related quantities based on SDSS and VST/ATLAS imaging. These data are provided in catalogue MGEPhotomUnregDR3 and are described in detail by D'Eugenio et al. (in prep).

Nov. 10, 2020 by S. Croom
Dec. 14, 2020, 4:13 a.m. L. Cortese