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Physical Sciences and Mathematics Commons

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East Tennessee State University

2006

Microlensing

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Microlensing Of Circumstellar Envelopes Iii. Line Profiles From Stellar Winds In Homologous Expansion., M. Hendry, Richard Ignace, H. Bryce May 2006

Microlensing Of Circumstellar Envelopes Iii. Line Profiles From Stellar Winds In Homologous Expansion., M. Hendry, Richard Ignace, H. Bryce

ETSU Faculty Works

This paper examines line profile evolution due to the linear expansion of circumstellar material obsverved during a microlensing event. This work extends our previous papers on emission line profile evolution from radial and azimuthal flow during point mass lens events and fold caustic crossings. Both “flavours” of microlensing were shown to provide effective diagnostics of bulk motion in circumstellar envelopes. In this work a different genre of flow is studied, namely linear homologous expansion, for both point mass lenses and fold caustic crossings. Linear expansion is of particular relevance to the effects of microlensing on supernovae at cosmological distances. We …


The Polarization Signature From Microlensing Of Circumstellar Envelopes In Caustic Cossing Events, Richard Ignace, J. Bjorkman, H. Bryce Feb 2006

The Polarization Signature From Microlensing Of Circumstellar Envelopes In Caustic Cossing Events, Richard Ignace, J. Bjorkman, H. Bryce

ETSU Faculty Works

In recent years, it has been shown that microlensing is a powerful tool for examining the atmospheres of stars in the Galactic bulge and Magellanic Clouds. The high gradient of magnification across the source during both small impact parameter events and caustic crossings offers a unique opportunity for determining the surface brightness profile of the source. Furthermore, models indicate that these events can also provide an appreciable polarization signal: arising from differential magnification across the otherwise symmetric source. Earlier work has addressed the signal from a scattering photosphere for both point mass lenses and caustic crossings. In a previous paper, …