Supplementing the 2MRS survey: The 2MZoA catalogue

Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, 85748 Garching, Germany

^★ Corresponding author: anja@mpe.mpg.de

Received: 11 September 2025
Accepted: 23 October 2025

Abstract

We present a homogeneous catalogue of verified 2MASX galaxies in high extinction areas that is complete to a Galactic extinction-corrected magnitude of K_s^o ≤ 11_⋅^m75. It covers the low Galactic latitudes (|b| ≤ 10_⋅^∘0), called Zone of Avoidance (ZoA), and areas of high foreground extinctions (E(B − V) > 0_⋅^m95) at higher latitudes. This catalogue supersedes the previously presented bright 2MZoA catalogue, which was only complete to K_s^o ≤ 11_⋅^m25. It fully complements the 2MASS Redshift Survey (2MRS) galaxy catalogue, which has the same magnitude limit but excludes high extinction regions. The combination of the two catalogues, the extended 2MRS or e2MRS, is a uniquely whole sky redshift survey of galaxies and forms a sound basis for studies of large-scale structures, cosmic flow fields, and extinction across the ZoA. The catalogue presented here comprises 6899 galaxies, with 6757 galaxies at low latitudes and 142 galaxies in highly obscured high-latitude areas. The completion rate in redshifts is almost 75%. The catalogue is complete up to star density levels of at least log N_*/deg² < 4.3, but the completion rate of the fainter part is affected by foreground extinction at all levels. This can be rectified by using a diameter-dependent extinction correction, which adds 605 highly obscured but apparently faint galaxies (with K_s^o > 11_⋅^m75 and K_s^o,d ≤ 11_⋅^m75) to the sample. This extended sample shows good completion rates with extinction up to at least A_K < 1_⋅^m3. Omission of such a diameter-dependent extinction correction may lead to a biased flow field even at intermediate extinction values as found in the 2MRS survey. As in our previous investigations, we recommend a correction factor of f = 0.86 be applied to the extinction maps, and we find it to be independent of Galactic longitudes or latitudes.