Variation of the ultraviolet extinction law across the Taurus-Auriga star-forming complex. A GALEX based study

The Taurus-Auriga molecular complex (TMC) is the main laboratory for the study of low-mass star formation. The density and properties of interstellar dust are expected to vary across the TMC. These variations trace important processes such as dust nucleation or the magnetic field coupling with the c...

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Detalles Bibliográficos
Autores: Gómez De Castro, Ana Inés, López Santiago, Javier, López Martínez, Fátima, Sánchez, Néstor, Castro Rubio, Elisa De, Cornide Castro-Piñeiro, Manuel
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/24082
Acceso en línea:https://hdl.handle.net/20.500.14352/24082
Access Level:acceso abierto
Palabra clave:52
Stars formation
ISM: clouds
Dust
Extinction
Ultraviolet ISM
Ultraviolet stars
Astronomía (Matemáticas)
21 Astronomía y Astrofísica
Descripción
Sumario:The Taurus-Auriga molecular complex (TMC) is the main laboratory for the study of low-mass star formation. The density and properties of interstellar dust are expected to vary across the TMC. These variations trace important processes such as dust nucleation or the magnetic field coupling with the cloud. In this paper, we show how the combination of near ultraviolet (NUV) and infrared (IR) photometry can be used to derive the strength of the 2175 Å bump and thus any enhancement in the abundance of small dust grains and polycyclic aromatic hydrocarbons in the dust grains size distribution. This technique is applied to the envelope of the TMC, mapped by the GALEXAll Sky Survey (AIS). Ultraviolet and IR photometric data have been retrieved from the GALEX-AIS and the 2MASS catalogues. NUV and K-band star counts have been used to identify the areas in the cloud envelope where the 2175 Å bump is weaker than in the diffuse interstellar medium namely, the low column density extensions of L1495, L1498 and L1524 in Taurus, L1545, L1548, L1519, L1513 in Auriga and L1482-83 in the California region. This finding agrees with previous results on dust evolution derived from Spitzer data and suggests that dust grains begin to decouple from the environmental Galactic magnetic field already in the envelope.