English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/20615
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

A high spatial resolution mid-infrared spectroscopic study of the nuclei and star-forming regions in luminous infrared galaxies

AutorDiza-Santos, T.; Alonso-Herrero, A. ; Colina, Luis ; Packham, Christopher; Levenson, N. A.; Pereira Santaella, Miguel; Roche, P. F.; Telesco, Charles M.
Palabras claveGalaxies: nuclei
Galaxies: star clusters
Galaxies: starburst
Infrared: galaxies
Fecha de publicación2-feb-2010
ResumenWe present a high spatial (diffraction-limited) resolution (~0.3") mid-infrared (MIR) spectroscopic study of the nuclei and star-forming regions of 4 local luminous infrared galaxies (LIRGs) using T-ReCS on the Gemini South telescope. We investigate the spatial variations of the features seen in the N-band spectra of LIRGs on scales of ~100 pc, which allow us to separate the AGN emission from that of the star formation (SF). We compare our Gemini T-ReCS nuclear and integrated spectra of LIRGs with those obtained with Spitzer IRS. The 9.7um silicate absorption feature is weaker in the nuclei of the LIRGs than in the surrounding regions. This is probably due to the either clumpy or compact environment of the central AGN or young, nuclear starburst. We find that the [NeII] luminosity surface density is tightly and directly correlated with that of Pa-alpha for the LIRG star-forming regions (slope of 1.00+-0.02). Although the 11.3um PAH feature shows also a trend with Pa-alpha, this is not common for all the regions. We also find that the [NeII]\Pa-alpha ratio does not depend on the Pa-alpha equivalent width (EW), i.e., on the age of the ionizing stellar populations, suggesting that, on the scales probed here, the [NeII] emission line is a good tracer of the SF activity in LIRGs. On the other hand, the 11.3um PAH\Pa-alpha ratio increases for smaller values of the Pa-alpha EW (increasing ages), indicating that the 11.3um PAH feature can also be excited by older stars than those responsible for the Pa-alpha emission. Additional high spatial resolution observations are essential to investigate, in a statistical way, the star formation in local LIRGs at the smallest scales and to probe ultimately whether they share the same physical properties as high-z LIRGs, ULIRGs and submillimiter galaxies.
Descripción24 pages, 19 figures, 7 tables, 1 appendix.
Versión del editorhttp://arxiv.org/abs/1001.1871
Aparece en las colecciones: (CFMAC-IEM) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
1001.1871v1.pdf2,62 MBAdobe PDFVista previa
Mostrar el registro completo

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.