Open AccessOn the nature of the near‐UV extended light in Seyfert galaxies
Author(s) -
Marín V. M. Muñoz,
StorchiBergmann T.,
Delgado R. M. González,
Schmitt H. R.,
Spinelli P. F.,
Pérez E.,
Cid Fernandes R.
Publication year - 2009
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2009.15317.x
Subject(s) - physics , astrophysics , galaxy , bulge , stellar population , astronomy , emission spectrum , star formation , doubly ionized oxygen , line (geometry) , ionization , population , spectral line , ion , geometry , mathematics , demography , quantum mechanics , sociology
We study the nature of the extended near‐UV emission in the inner kiloparsec of a sample of 15 Seyfert (Sy) galaxies which have both near‐UV (F330W) and narrow‐band [O iii ] high‐resolution Hubble images. For the majority of the objects, we find a very similar morphology in both bands. From the [O iii ] images, we construct synthetic images of the nebular continuum plus the emission‐line contribution expected through the F330W filter, which can be subtracted from the F330W images. We find that the emission of the ionized gas dominates the near‐UV extended emission in half of the objects. A further broad‐band photometric study, in the bands F330W ( U ), F547M ( V ) and F160W ( H ), shows that the remaining emission is dominated by the underlying galactic bulge contribution. We also find a blue component whose nature is not clear in four out of 15 objects. This component may be attributed to scattered light from the active galactic nuclei, to a young stellar population in unresolved star clusters, or to early disrupted clusters. Star‐forming regions and/or bright off nuclear star clusters are observed in 4/15 galaxies of the sample.