Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-05-05
Astronomy and Astrophysics
Astrophysics
22 pages, 10 figures, accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20054302
In order to show the importance of high spatial resolution observations of extra-galactic sources when compared to observations obtained with larger apertures such as ISO, we present N-band spectra (8-13 um) of some locations in three starburst galaxies. In particular, the two galactic nuclei of the spiral galaxy NGC3256, the compact IR supernebula in the dwarf galaxy IIZw40 and the two brightest IR knots in the central starburst of the WR galaxy He2-10. The spectra have been obtained with TIMMI2 on the ESO 3.6m telescope. An inventory of the spectra in terms of atomic fine-structure lines and molecular bands is presented. We show the great value of these high spatial resolution data at constraining properties such as the extinction in the mid-IR, metallicity or stellar content (age, IMF, etc.). Regarding this, we have constrained the stellar content of the IR compact knot in IIZw40 by using the mid-IR fine-structure lines and setting restrictions on the nebular geometry. Considering the PAH bands, we have constructed a new mid-/far-IR diagnostic diagram based on the 11.2 um PAH and continuum, accessible to ground-based observations. Finally, we find a dependence between the presence or non-presence of PAHs and the hardness of the radiation field as measured by the [SIV]/[NeII] ratio. In particular, sources with PAH emission have in general a [SIV]/[NeII] ratio < 0.35. We investigate possible origins for this relation and conclude that it does not necessarily imply PAH destruction, but could also be explained by the PAH-dust competition for FUV photons.
Martin-Hernandez N. L.
Peeters Els
Sauvage Marc
Schaerer Daniel
Tielens Alexander G. G. M.
No associations
LandOfFree
High spatial resolution mid-infrared spectroscopy of the starburst galaxies NGC 3256, IIZw40 and Henize 2-10 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with High spatial resolution mid-infrared spectroscopy of the starburst galaxies NGC 3256, IIZw40 and Henize 2-10, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High spatial resolution mid-infrared spectroscopy of the starburst galaxies NGC 3256, IIZw40 and Henize 2-10 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-608293