A Zone of Avoidance catalogue of 2MASS bright galaxies. I. Sample description and analysis

We present a homogeneous 2MASS bright galaxy catalogue at low Galactic latitudes ($\mathrm{\mid }b\mathrm{\mid }\le {10.0}^{\mathrm{o}}$, called Zone of Avoidance) which is complete to a Galactic extinction-corrected magnitude of $K_s^o\le {11.25}^{\mathrm{m}}$. It also includes galaxies in regions of high foreground extinctions ($E(B-V) > 0.95^{\rm m}$) situated at higher latitudes. This catalogue forms the basis of studies of large-scale structures, flow fields and extinction across the ZoA and complements the ongoing 2MASS Redshift and Tully-Fisher surveys. It comprises 3763 galaxies, 70% of which have at least one radial velocity measurement in the literature. The catalogue is complete up to star density levels of $\log N_{\ast }\mathrm{/}{\mathrm{d}\mathrm{e}\mathrm{g}}^2<4.5$ and at least for $A_K<{0.6}^{\mathrm{m}}$ and likely as high as $A_K={20}^{\mathrm{m}}$. Thus the ZoA in terms of bright NIR galaxies covers only $2.5-4$% of the whole sky. We use a diameter-dependent extinction correction to compare our sample with an unobscured, high-latitude sample. While the correction to the $K_s$ -band magnitude is sufficient, the corrected diameters are too small by about $4^{\mathrm{\prime }\mathrm{\prime }}$ on average. The omission of applying such a diameter-dependent extinction correction may lead to a biased flow field even at intermediate extinction values as found in the 2MRS survey. A slight dependence of galaxy colour with stellar density indicates that unsubtracted foreground stars make galaxies appear bluer. Furthermore, far-infrared sources in the DIRBE/IRAS extinction maps that were not removed at low latitudes affect the foreground extinction corrections of three galaxies and may weakly affect a further estimated $\approx 20$% of our galaxies.