| Full text | |
| Author(s): |
Martins, L. P.
[1]
;
Lanfranchi, G.
[1]
;
Goncalves, D. R.
[2, 3]
;
Magrini, L.
[4]
;
Teodorescu, A. M.
[5]
;
Quireza, C.
[2]
Total Authors: 6
|
| Affiliation: | [1] NAT Univ Cruzeiro Sul, BR-01506000 Sao Paulo - Brazil
[2] UFRJ Obser Valongo, BR-20080090 Rio De Janeiro - Brazil
[3] Univ London Univ Coll, Dept Phys & Astron, London WC1E 6BT - England
[4] INAF Osservatorio Astrofis Arcetri, I-50125 Florence - Italy
[5] Univ Hawaii, Inst Astron, Honolulu, HI 96822 - USA
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 419, n. 4, p. 3159-3166, FEB 2012. |
| Web of Science Citations: | 5 |
| Abstract | |
NGC 185 is a dwarf spheroidal satellite of the Andromeda galaxy. From mid-1990s onwards it was revealed that dwarf spheroidals often display a varied and in some cases complex star formation history. In an optical survey of bright nearby galaxies, NGC 185 was classified as a Seyfert galaxy based on its emission line ratios. However, although the emission lines in this object formally place it in the category of Seyferts, it is probable that this galaxy does not contain a genuine active nucleus. NGC 185 was not detected in radio surveys either in 6 or 20 cm, or X-ray observations, which means that the Seyfert-like line ratios may be produced by stellar processes. In this work, we try to identify the possible ionization mechanisms for this galaxy. We discussed the possibility of the line emissions being produced by planetary nebulae (PNe), using deep spectroscopy observations obtained with the Gemini Multi-Object Spectrograph North (GMOS-N), at Gemini. Although the fluxes of the PNe are high enough to explain the integrated spectrum, the line ratios are very far from the values for the Seyfert classification. We then proposed that a mixture of supernova remnants and PNe could be the source of the ionization, and we show that a composition of these two objects do mimic Seyfert-like line ratios. We used chemical evolution models to predict the supernova rates and to support the idea that these supernova remnants should be present in the galaxy. (AU) | |
| FAPESP's process: | 11/00171-4 - A high-resolution stellar library for stellar population synthesis |
| Grantee: | Lucimara Pires Martins |
| Support Opportunities: | Regular Research Grants |