Role of nonthermal velocity fields in determining the H-alpha widths in supergiant chromospheres

dc.contributor.author	Mallik, S. G. V
dc.date.accessioned	2009-08-10T14:58:30Z
dc.date.available	2009-08-10T14:58:30Z
dc.date.issued	1990-10
dc.identifier.citation	Publications Astronomical Society of the Pacific, Vol. 102, pp. 1148 - 1152	en
dc.identifier.issn	0004-6280
dc.identifier.uri	http://hdl.handle.net/2248/4749
dc.description.abstract	Radiative transfer calculations of the H-alpha line in spherically symmetric, expanding chromospheres explain the large widths of the line observed in late G and K supergiants. The role of various dynamical processes as well as that of opacity in determining the H-alpha width is illustrated. The H-alpha line profile is basically characterized by large optical depths and large Doppler broadening velocity. The calculations show that the existence of large microturbulence has to be invoked in the chromosphere to understand the observed widths.	en
dc.language.iso	en	en
dc.publisher	The Astronomical Society of the Pacific.	en
dc.relation.uri	http://adsabs.harvard.edu/abs/1990PASP..102.1148M	en
dc.relation.uri	http://dx.doi.org/10.1086/132745	en
dc.rights	© Astronomical Society of the Pacific.	en
dc.subject	Radiative Transfer: H-alpha line	en
dc.subject	Chromosphere: Late-Type Supergiants	en
dc.title	Role of nonthermal velocity fields in determining the H-alpha widths in supergiant chromospheres	en
dc.type	Article	en