The nature of G52.381-0.849 and G56.240-0.345: young stellar objects associated with extended mid-infrared emission - Astrophysics > Astrophysics of GalaxiesReportar como inadecuado




The nature of G52.381-0.849 and G56.240-0.345: young stellar objects associated with extended mid-infrared emission - Astrophysics > Astrophysics of Galaxies - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We report the results of visual spectroscopy, mid-infrared MIR mapping andphotometry, and near-infrared photometry of two candidate symbiotic starsIPHAS J193108.67+164950.5 and IPHAS J193709.65+202655.7 associated withextended MIR emission. Our analysis of the continua of these sources shows thatthey are likely to represent Class I-II young stellar objects YSOs in whichmost of the IR emission arises from circumstellar discs, and for which thephysical characteristics stellar temperatures, radii, masses and luminositiesare similar. The extended emission is characterized by a substantial increasein fluxes and dimensions to longer MIR wavelengths. This is likely to arise asa result of emission by polycyclic aromatic hydrocarbons within extendedphotodissociation regimes, centred upon more compact ionized regionsresponsible for much of the shorter wave emission. Such dual emissionstructures are characteristic of those observed in many compact HII regions.Finally, we note that the clouds have asymmetrical structures and wind-sweptmorphologies, conceivably indicative of shock interaction with external winds.Where this is the case, then it is possible that the YSOs are located inregions of triggered star formation.



Autor: J. P. Phillips, J. A. Perez-Grana, G. Ramos-Larios, S. Velasco-Gas

Fuente: https://arxiv.org/







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