Infrared and optical properties of the emission-line galaxies NGC 1386 and NGC 1365
We have obtained optical spectrophotometry and broad-band infrared data for the nucleus of the emission-line galaxy NGC 1386. These observations are discussed and compared with our own optical spectrophotometry as well as published optical and infrared measurements of the nucleus of the neighboring ''hot spot'' galaxy NGC 1365. Both galaxies show large infared excesses. The very high excitation emission-line spectrum of NGC 1386 is that of a type of 2 Seyfert, making this galaxy the closest known member of this class of objects. We find direct evidence for a significant early-type stellar population in the nucleus of NGC 1365, thus strengthening the previous conclusion that the nuclear emission lines of this galaxy are excited by the radiation of young, hot stars. In addition, we confirm the presence of weak (Ne V) and He II emission, which suggests that a nonthermal source of ionization may also be present. The nucleus of NGC 1365 is emitting a factor of 10 more energy in both the optical emission lines and the infrared than is that of NGC 1386. Finally, we point out the uncertainty in identification of NGC 1365 as an X-ray source in view of its proximity of a Seyfert 2, galaxy, several of which have now been shown to be strong X-ray emitters.
- Research Organization:
- Cerro Tololo Inter-American Observatory
- OSTI ID:
- 5364217
- Journal Information:
- Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 235:3; ISSN ASJOA
- Country of Publication:
- United States
- Language:
- English
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