# AUTHOR: CALIFA collaboration
# SOURCE: SDSS, Galex, 2MASS
# DATE: 2014-09-09
# VERSION: 1.0
# COLAPRV: none
# PUBAPRV: None 

This catalogue presents a match of UV, optical and NIR photometric data. All magnitudes are 
on the AB system. 

The optical growth curve magnitudes from the SDSS images are given in the precedent catalogue. 

The Galex photometry is described in Catalan et al., in prep. 

The 2MASS photometry is from the 2MASS All-Sky Extended Source Catalog (XSC) catalog providing 
J,H,Ks photometry. It was retrieved directly from the NASA/IPAC Infrared Science Archive at 
http://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-scan?mission=irsa&submit=Select&projshort=2MASS&BOLOCAM=bolocam_gps_v1_0_1&DENIS=denis3
The CALIFA galaxy coordinates were used to find extended 2MASS source entries within 20arcsec, 
with 924 positive matches. Please note that for some galaxies the 2MASS coordinates can be 
significantly of from the galaxy center by more than 10arcsec. 

This can have various reasons:
1. Confusion with a nearby bright star
2. Noise peaks due to the faintness of a galaxy
3. The NIR emission peaks off-center in the galaxy
This does not mean that the photometry is not reliable if the offset is large, but it might be beneficial 
to check the corresponding 2MASS image to be sure.

Information on the details about the 2MASS XSC photometry can be found at 
http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec4_5.html .
Followed by some cautionary notes http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec1_6c.html

Some magnitudes are not to be believed or objects are not detected. For these the 
error on the magnitude was set to 30. A chi2 fitting code will thus disregard these 
magnitudes automatically. For any other application one may have to mask magnitudes 
with large errors, which should be easy to do.