Reference : A generalized method for deriving mass-loss rates - The first order moment of unsatur...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/22114
A generalized method for deriving mass-loss rates - The first order moment of unsaturated P Cygni line profiles
English
Surdej, Jean mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Feb-1983
Astrophysics & Space Science
Springer Science & Business Media B.V.
90
299-311
Yes (verified by ORBi)
International
0004-640X
Dordrecht
The Netherlands
[en] LINE SPECTRA ; STELLAR ENVELOPES ; STELLAR MASS EJECTION ; STELLAR MOTIONS ; STELLAR SPECTRA ; NUMERICAL INTEGRATION ; OPTICAL THICKNESS ; RADIAL VELOCITY ; B STARS
[en] For the case of optically thin lines, we show that the relation existing between the first order moment W1 ~ j (E(2)/E~ - 1)(2 - 212) d2 of a P Cygni profile and the quantity ii~in(1eve1), where M is the mass-loss rate of the central star and n(level) the fractional abundance of the ion under study, is in fact independent of any Sobolev-type approximations used for the transfer of line radiation, contrary to what has been assumed in some previous works (Castor eta!., 1981; Surdej, 1982). Consequently, all results established in the context of'very rapidly' expanding atmospheres and mainly referring to the non-dependence of W1 vs various physical (underlying photospheric absorption line, limb darkening, etc.) and geometrical (velocity field v(r), etc.) effects remain unchanged for arbitrary (e.g. non-Sobolev type) outward-accelerating velocity laws. Whenever applied with caution, Equation (50) thus provides a very powerful means of deriving mass-loss rates - with a total uncertainty less than 60 percent - from the measurement W1 of unsaturated P Cygni profiles observed in the spectrum of early - as well as late - type stars, quasars, etc
Researchers ; Professionals
http://hdl.handle.net/2268/22114
10.1007/BF00650064
http://esoads.eso.org/abs/1983Ap%26SS..90..299S
The authors thank SAO/NASA ADS Astronomy Abstract Service for their deposit authorization. The original publication is available at www.springerlink.com.

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Open access
Surdej_ASS_1983_90_299_311.pdfPublisher postprint761.58 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.