Sebastien Muller (Chalmers University of Technology, Sweden)
Warning : Seminar moved to Friday November 20th - 11am
IPAG Seminar Room - IPAG
The molecular absorber at z=0.89 in the line of sight of the lensed blazar PKS1830-211 is a unique source to investigate the physico-chemical properties of the ISM in the disk of a distant galaxy, with now about 50 different molecules detected.
I will present the latest ALMA results on this source (mostly focussing on hydride species), and show how the molecules can be used as powerful cosmological probes (temperature of the cosmic microwave background, evolution of isotopic ratios, constancy of fundamental constants). Besides the molecular absorption, the ALMA data provide unprecedented information on the intrinsic activity of the blazar itself. In particular, some observations were coincident in time with a strong gamma-ray flare. Finally, we used a new method of differential polarization calibration to measure the Faraday rotation toward the blazar, suggesting a strong magnetic field close to its black hole.
Dans la même rubrique :