Dim galaxies and outer halos of galaxies missed by 2MASS? The near–infrared luminosity function and density
INAF – Osservatorio Astronomico di Capodimonte, Naples, Italy
Corresponding author: email@example.com
Accepted: 6 November 2001
By using high–resolution and deep Ks band observations of early–type galaxies of the nearby Universe and of a cluster at we show that the two luminosity functions (LFs) of the local universe derived from 2MASS data miss a fair fraction of the flux of the galaxies (more than 20 to 30%) and a whole population of galaxies of central brightness fainter than the isophote used for detection, but bright enough to be included in the published LFs. In particular, the fraction of lost flux increases as the galaxy surface brightness become fainter. Therefore, the so far derived LF slopes and characteristic luminosity as well as luminosity density are underestimated. Other published near–infrared LFs miss flux in general, including the LF of the distant field computed in a 3 arcsec aperture.
Key words: galaxies: evolution / galaxies: clusters: general / X-rays: general
© ESO, 2002