[34.01] Microlensing Effects on Emission Lines from Homologously Expanding Winds

AAS 205th Meeting, 9-13 January 2005
Session 34 Stellar Structure and Evolution
Oral, Monday, January 10, 2005, 10:00-11:30am, Royal Palm 4-6

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[34.01] Microlensing Effects on Emission Lines from Homologously Expanding Winds

R. Ignace (ETSU), H. M. Bryce, M.A. Hendry (U. of Glasgow)

We have been investigating the influence of microlensing on a variety of spectroscopic signatures relevant to circumstellar flows. Here we report on recent results for line profiles that form in spherically symmetric winds during a microlensing event. As a convenient test case, we have adopted a homologous velocity law (v \propto r, from r=R_phot to r_max). Results are discussed for resonance scattering P Cygni lines and recombination emission lines. Somewhat surprisingly, the rectified line profiles show rather mild variations in response to microlensing. The reason is that both the line emission from the extended wind and the stellar photosphere are lensed, so that the strong magnification effects of lensing seen in either component are partially supressed when showing the continuum normalized spectrum (which is the common form of display for such data). Still, significant and observable variations in the line equivalent width do result.

This research has been supported in part by NSF grant AST-0354261.

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