Portal de Periódicos da CAPES

The nuclei of peculiar emission-line galaxies.

1974; IOP Publishing; Volume: 192; Linguagem: Inglês

10.1086/153058

1538-4357

Patrick S. Osmer, M. G. Smith, D. W. Weedman,

Astrophysical Phenomena and Observations

view Abstract Citations (162) References (57) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The nuclei of peculiar emission-line galaxies. Osmer, P. S. ; Smith, M. G. ; Weedman, D. W. Abstract The nature of the nuclear activity in six Sersic-Pastoriza spirals with morphologically peculiar nuclei (NGC 613, 1097, 1365, 1672, 1808, and 2997), in the peculiar galaxy NGC 5253, and in the interacting galaxy NGC 2992, is studied using spectrophotometry of emission lines and continua. In the Sersic-Pastoriza nuclei the emission spectra are similar to those of normal H ii regions except that the Balmer decrements are very steep, indicative of large reddening. Hot stars are the most plausible source of ionizing radiation; their contribution to the optical continuum is masked by the interstellar absorption. After correction for interstellar absorption, the Hfl luminosities are one to two orders of magnitude larger than those of typical giant H ii regions. Such large numbers of ionizing stars are required that the present levels of activity must result from transitory bursts of star formation. The emission-line region in NUC 5253 has higher excitation and a much bluer continuum than the Sersic-Pastoriza nuclei, and the reddening is relatively small. The total H emission is comparable to that of a typical giant H ii region and consequently the present rate of star formation could have been supported for a much longer time than in the Sersic-Pastoriza nuclei. NGC 2992 has both very high excitation and a steep Balmer decrement which, if caused by reddening, leads to a luminosity in H comparable to that of the brighter Seyfert galaxies. Its activity may be related to the interaction with the nearby NUC 2993. Subject headings: galactic nuclei - nebulae Publication: The Astrophysical Journal Pub Date: September 1974 DOI: 10.1086/153058 Bibcode: 1974ApJ...192..279O full text sources ADS | data products NED (8)