Extended UV (XUV) Emission in Nearby Galaxy Disks

We summarize the main properties of the extended UV (XUV) emission found in roughly 30% of the nearby spiral galaxies observed by the GALEX satellite. Two different classes of XUV disks are identified, the Type 1 XUV disks where significant, structured UV-bright features are found beyond the classic...

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Detalles Bibliográficos
Autores: Gil De Paz, Armando, Díaz Lopez, Cristina, Zamorano Calvo, Jaime, Gallego Maestro, Jesús, Muñoz Mateos, Juan Carlos, Pérez González, Pablo Guillermo
Tipo de recurso: capítulo de libro
Fecha de publicación:2008
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/53473
Acceso en línea:https://hdl.handle.net/20.500.14352/53473
Access Level:acceso abierto
Palabra clave:52
Spiral galaxies
Star-formation
Ultraviolet disk
Evolution
Spectroscopy
Abundances
NGC-4625
M83
Astrofísica
Astronomía (Física)
Descripción
Sumario:We summarize the main properties of the extended UV (XUV) emission found in roughly 30% of the nearby spiral galaxies observed by the GALEX satellite. Two different classes of XUV disks are identified, the Type 1 XUV disks where significant, structured UV-bright features are found beyond the classical azimuthally-averaged star-formation threshold, and the Type 2 XUV disks, which are characterized by very extended (seven times the area where most of the stellar mass is found), blue ((FUV-K)<5 mag) outer disks. These latter disks are extreme examples of galaxies growing inside-out. The few XUV disks studied in detail to date are rich in H I but relatively poor in molecular gas, have stellar populations with luminosity-weighted ages of ∼1 Gyr, and ionized-gas metal abundances of ∼Z_⊙/10. As part of the CAHA-XUV project we are in the process of obtaining deep multi-wavelength imaging and spectroscopy of 65 XUV-disk galaxies so to determine whether or not these properties are common among XUV disks.