Título
A Spitzer-IRS Spectroscopic atlas of early-type galaxies in the Revised Shapley-Ames Catalog
Autor
OLGA MERCEDES VEGA CASANOVA
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
We produce an atlas of homogeneously reduced and calibrated low resolution IRS spectra of the nuclear regions of nearby early-type galaxies (i.e. Es and S0s, ETGs), in order to build a reference sample in the mid-infrared window. From the Spitzer Heritage Archive we extract ETGs in the Revised Shapley-Ames Catalog of Bright Galaxies having an IRS SL and/or LL spectrum. We recover 91 spectra out of 363 galaxies classified as ETGs in the catalog: 56 E (E0-E6), 8 mixed E/S0+S0/E, 27 S0 (both normal and barred - SB0) plus mixed types SB0/Sa+SB0/SBa. For each galaxy, we provide the fully reduced and calibrated spectrum, the intensity of nebular and molecular emission lines as well as of the Polycyclic Aromatic Hydrocarbons (PAHs) after a template spectrum of a passively evolving ETG has been subtracted. Spectra are classified into five mid-infrared classes, ranging from AGN (class-4) and star forming nuclei (class-3), transition class-2 (with PAHs) and class-1 (no-PAHs) to passively evolving nuclei (class-0). A demographic study of mid-infrared spectra shows that Es are significantly more passive than S0s:46⁺¹¹₋₁₀% of Es and 20⁺¹¹₋₇ % of S0s have a spectrum of class-0. Emission lines are revealed in 64⁺¹²₋₆ % of ETGs. The H₂S(1) line is found with similar rate in Es (34⁺¹⁰₋₈ %) and in S0s (51⁺¹⁵₋₁₂%). PAHs are detected in 47⁺⁸₋₇% of ETGs, but only 9⁺⁴₋₃% have PAHs ratios typical of star forming galaxies. Several indicators, such as peculiar morphologies and kinematics, dust–lane irregular shape, radio and X-ray properties, suggest that mid-infrared spectral classes are connected to phases of accretion/feedback phenomena occurring in the nuclei of ETGs.
Editor
Monthly Notices of the Royal Astronomical Society
Fecha de publicación
19 de marzo de 2013
Tipo de publicación
Artículo
Versión de la publicación
Versión aceptada
Recurso de información
Formato
application/pdf
Idioma
Inglés
Audiencia
Estudiantes
Investigadores
Público en general
Sugerencia de citación
Rampazzo, R., et al., (2013), A Spitzer-IRS Spectroscopic atlas of early-type galaxies in the Revised Shapley-Ames Catalog, Monthly Notices of the Royal Astronomical Society, Vol. 432(1):374-403
Repositorio Orígen
Repositorio Institucional del INAOE
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