Wind Inhomogeneities in Wolf-Rayet Stars. III. Unusual Emission-Line Profile Variations in [FORMULA][F]γ[SUP]2[/SUP][/F][/FORMULA] Velorum

1999 ◽  
Vol 117 (3) ◽  
pp. 1441-1453 ◽  
Author(s):  
Sébastien Lépine ◽  
Thomas Eversberg ◽  
Anthony F. J. Moffat
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Emission Line Profile

Anomalous Hα Emission Line Profile Detected at the Center of DDO 53

2021 ◽  
Vol 919 (2) ◽  
pp. 73
Author(s):  
Justin A. Kader ◽  
Liese van Zee ◽  
Kristen B. W. McQuinn ◽  
Laura C. Hunter
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Hα Emission ◽  
Emission Line Profile

scholarly journals Emission-line-profile variability as a contraint on the structure and dynamics of hot star winds

2003 ◽  
Vol 212 ◽  
pp. 168-169
Author(s):  
Luc Dessart ◽  
Stanley P. Owocki
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Theoretical Calculations ◽  
Line Center ◽  
Radiation Hydrodynamics ◽  
Velocity Scale ◽  
Centre Region ◽  
Lateral Extent ◽  
Emission Line Profile ◽  
Hot Star Winds

We present theoretical calculations of emission-line-profile variability (LPV), based on radiation hydrodynamics simulations of the infamous radiative instability of hot star winds. We demonstrate that spherically symmetric wind structures (shells) cannot account for the observed profile variability at line center. Hence, we resort to a model that breaks-up the wind volume into a number of independent star-centered cones. The essential approximation made here is that each of these cones can be described by a structure calculated with a one-dimensional (1d) radiation hydrodynamics model. Such pseudo-3d ‘patch’-method leads to a satisfactory reproduction of the fundamental characteristics of LPV observed in O-type and Wolf-Rayet star optical spectra: the low-level fluctuations in the profile centre region, a migration of variable sub-peaks from line center to edge, that mimics the underlying wind acceleration. Our method highlights the correlation between the velocity scale of profile sub-peaks at line center and the lateral extent of wind structures, while at line edge it reflects the intrinsic radial velocity dispersion of emitting clumps. However, our model fails to reproduce the increase in this characteristic velocity scale from line center to edge, which we believe is a shortcoming of our purely 1d hydrodynamics approach.

Sign in / Sign up

Export Citation Format

Share Document