Résumé / Abstract Seminaire_IAP
« A calibration of the stellar-mass fundamental plane at z = 0.4 using the micro-lensing induced flux ratio anomalies of macro-lensed quasars  »

Paul L. Schechter
Massachusett Inst. Technology (MIT) (Cambridge, Massachusetts, Etats-Unis d'Amérique)

So-called "stellar" masses for early type galaxies are almost always determined by one of two methods: either they are estimated from spectra (and sometimes only broad band colors) or they are deduced by subtracting the contribution of an assumed dark matter profile from a combined mass inferred from kinematic (and sometimes macro-lensing) measurements. Both methods have shortcomings. We describe a third method: the analysis of flux ratio anomalies caused by the micro-lensing of quadruply imaged quasars by the stellar graininess of the lensing galaxy (Schechter and Wambsganss 2004). We use X-ray observations from the Chandra Observatory (Pooley et al 2012) to measure flux ratio anomalies and the "stellar mass fundamental plane" of Hyde and Bernardi (2009) and to average results obtained at different radii from galaxies of different sizes and at different redshifts. We infer limits on the underlying stellar intial mass function.
vendredi 6 décembre 2013 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage