Morphological classifications of APM galaxies

DOI

We investigate the consistency of visual morphological classifications of galaxies by comparing classifications for 831 galaxies from six independent observers. The galaxies were classified on laser print copy images or on computer screen using scans made with the Automated Plate Measuring (APM) machine. Classifications are compared using the Revised Hubble numerical type index T. We find that individual observers agree with one another with rms combined dispersions of between 1.3 and 2.3 type units, typically about 1.8 units. The dispersions tend to decrease slightly with increasing angular diameter and, in some cases, with increasing axial ratio (b/a). The agreement between independent observers is reasonably good but the scatter is non-negligible. In spite of the scatter, the Revised Hubble T system can be used to train an automated galaxy classifier, e.g. an artificial neural network, to handle the large number of galaxy images that are being compiled in the APM and other surveys.

Cone search capability for table J/MNRAS/274/1107/experts (Unified table of T-type classifications and mean types)

Identifier
DOI http://doi.org/10.26093/cds/vizier.72741107
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/274/1107
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/274/1107
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/274/1107
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/274/1107
Provenance
Creator Naim A.; Lahav O.; Buta R.J.; Corwin H.G.Jr.; De Vaucouleurs G.,Dressler A.; Huchra J.P.; Van Den Bergh S.; Raychaudhury S.; Sodre L.Jr,Storrie-Lombardi M.C.
Publisher CDS
Publication Year 2000
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Observational Astronomy; Physics