Se presenta espectroscopia de alta resolucion espacial con T-ReCS en la banda N (8− 13 µm) de las regiones centrales (unos pocos kpc) de tres galaxias infrarrojas (IR) luminosas (LIRGs) locales. Los espectros nucleares presentan una profunda banda de absorci´on de los silicatos a 9.7 µm y la l´ınea de emisi´on de [S iv]10.5 µm en acuerdo con su clasificacion como AGN. Las dos LIRGs con emision en el IR medio no resuelta no muestran emisi´on PAH en 11 . 3 µm en sus espectros nucleares. Para NGC 5135 los datos de T-ReCS nos han permitido resolver los espectros del n´ucleo, una regi´on H ii y la zona difusa entre ambos, en escalas menores que 2 .5′′ ∼ 600 pc. La zona difusa presenta emisi´on PAH brillante con un continuo d´ebil, mientras que la regi´on H ii presenta emision PAH con menor anchura equivalente y la l´ınea de [Ne ii]12. 8 µm.

We present T-ReCS high spatial resolution N-band (8− 13 µm) spectroscopy of the central regions (a few kpc) of 3 local LIRGs. The nuclear spectra show deep 9.7 µm silicate absorption feature and the high ionization [S iv]10. 5 µm, emission line, consistent with their optical classification as AGN. The two LIRGs with unresolved mid-IR emission do not show PAH emission at 11. 3 µm in their nuclear spectra. The spatially resolved mid-IR spectroscopy of NGC 5135 allows us to separate out the spectra of the Seyfert nucleus, an H ii region, and the diffuse region between them on scales of less than 2 . 5 ′′ ∼ 600 pc. The diffuse region spectrum is characterized by strong PAH emission with almost no continuum, whereas the H ii region shows PAH emission with a smaller equivalent width as well as [Ne ii]12 . 8 µm line.

Support was provided by the Spanish PNE (ESP2005-01480) and the NSF (0206617). Based on observations obtained at the Gemini Observatory, which is operated by AURA, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: NSF (USA), PPARC (UK), NRC (Canada), CONICYT (Chile), ARC (Australia), CNPq (Brazil) and CONICET (Argentina).

3 pags., 3 figs.

Peer reviewed