Il est visible que la classification via "mass" et "angular" ne suffit pas, le "morphology" est toujours aussi présent...
"Our goal is to develop a new and reliable statistical method to classify galaxies from large surveys. We probe the reliability of the method by comparing it with a three-dimensional classification cube, using the same set of spectral, photometric and morphological parameters
" Methods: We applied two different methods of classification to a sample of galaxies extracted from the zCOSMOS redshift survey, in the redshift range 0.5 ≲ z ≲ 1.3. The first method is a combination of three independent classification schemes - a spectroscopic one based on the strength of the continuum break at 4000 Å and the rest-frame equivalent width of the [O ii] emission line, a photometric one based on the observed B - z colours, and a morphological one
"The second method exploits an entirely new approach based on statistical analyses like principal component analysis (PCA) and unsupervised fuzzy partition (UFP) clustering method. The PCA+UFP method has also been applied to a lower redshift sample (z ≲ 0.5), exploiting the same set of data but replacing the spectroscopic indicators with the equivalent width of Hα."
"Results: The comparison between the two methods shows fairly good agreement on the definition on the two main populations, the early-type and the late-type galaxies. "
" galaxies with masses of the order of 3 × 1010 M⊙ are predominantly found in the transition from the late-type to early-type group at z > 0.5, while galaxies with lower masses, of the order of 1010 M⊙, are in transition at later epochs. Galaxies with M < 1010 M⊙ have not yet begun to transition, while galaxies with very large masses (M > 5
× 1010 M⊙) have mostly completed their transition to the early-type regime before z ~ 1."
Clairement, cela ne suffira pas pour tous les derniers... Et ils en sont conscient.
Il faut toujours viser la Lune, car même en cas d'échec, on atterrit dans les étoiles.