Free Access
Volume 545, September 2012
Article Number A15
Number of page(s) 15
Section Extragalactic astronomy
Published online 29 August 2012

Online material

Appendix A: Additional data

There are some additional data associated with this study: a) SDSS photometric data that were processed but not used for this study and b) Hyperleda data that were compiled for the comparison presented in Sect. 4. These data are presented here and in for future reference and to allow the data replication and reproducibility.

A diagram of the samples and data presented in the paper is shown in Fig. A.1.

A.1. SDSS photometric data

We cross-correlated the positions of our galaxies (Leon & Verdes-Montenegro 2003) with the SDSS DR6 photometric catalogue using the interface available on the SDSS web-page (search radius of 0.5′). We obtained a list of photometric sources near the estimated centre of each galaxy as well as the corresponding SDSS spectral data when available. The right objects were identified using a semi-automatic selection algorithm selecting the object with the highest z band flux followed by a visual inspection as a cross-check. Only  ~8% of the photometric objects were clearly misclassified with the usual source of confusion involving a nearby star. A total of 549 AMIGA galaxies were included in DR6.

In six cases the photometry for the galaxy was assigned to an object whose estimated position was shifted from the centre of the galaxy. In these cases, we manually chose the correct photometric object. We inspected in more detail some special cases that were finally discarded from our catalogue (CIG 402 is strongly affected by the light of a nearby star and CIG 802 and 388 are resolved Milky Way satellites). As a final check we compared the apparent magnitudes in g-band from the SDSS data and in B-band from the AMIGA database (Verdes-Montenegro et al. 2005). Although the filter shapes are different and the shape of the spectral energy distribution of the galaxy directly affects their ratio, a high difference between these two magnitudes may indicate an error in the selection of the photometric data. The mean of the ratio is 1.044 and the standard deviation is 0.070. In seven cases the difference was found to be above 3σ, suggesting that the SDSS photometric data might refer to a restricted region rather than the entire galaxy. The photometric data for these cases were flagged. The values for the SDSS photometry are presented in Table A.1.

thumbnail Fig. A.1

Description of the samples and data presented in the different tables within the paper.

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A.2. Hyperleda data

Hyperleda data were compiled for the AMIGA and HCG samples (see Sect. 4). In Table A.2, the compiled morphological classification and absolute magnitude for AMIGA galaxies are shown. In Table A.3, the compiled morphological classification and absolute magnitude plus the nuclear activity classification obtained from Martínez et al. (2010) are shown.

Table A.1

Catalogue of SDSS photometry.

Table A.2

Hyperleda data for AMIGA galaxies.

Table A.3

Hyperleda data for HCG galaxies.

© ESO, 2012

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