Bibcode
Laurikainen, E.; Salo, H.; Buta, R.; Knapen, J. H.
Referencia bibliográfica
Advances in Astronomy, vol. 2011, id.516739
Fecha de publicación:
2011
Número de citas
6
Número de citas referidas
6
Descripción
A review of the results of the Near-IR S0 galaxy Survey (NIRS0S) is
presented. NIRS0S is a magnitude (mB 12.5 mag) and inclination (<
65o) limited sample of 200 nearby galaxies, mainly S0s. It uses deep Ks
-band images, typically reaching a surface brightness of 23.5 mag
arcsec^(-2) . Detailed visual and photometric classifications were made,
for the first time coding also the lenses in a systematic manner. As a
comparison sample, a similar sized spiral galaxy sample with similar
image quality was used. The main emphasis were to study whether the S0s
are former spirals in which star formation has been ceased, and also,
how robust are bars in galaxies. Based on our analysis the Hubble
sequence was revisited: following the early idea by van den Bergh we
suggested that the S0s are spread throughout the Hubble sequence in
parallel tuning forks as spirals (S0a, S0b, S0c etc.). This is evidenced
by our improved bulge-to-total (B/T) flux ratios, reaching as small
values as typically found in late-type spirals. The properties of bulges
and disks in S0s were found to be similar to those in spirals. Also, the
masses and scale parameters of the bulges and disks were found to be
coupled. Bars were found to be fairly robust both in S0s and spirals,
but inspite of that bars might evolve significantly within the Hubble
sequence.