A Search For Signatures of Dark Matter in Ultra-high Precision VLBI Astrometry

March 1, 3:30pm - 4:30pm
Mānoa Campus, Wat. 112 Add to Calendar

Department of Physics and Astronomy Colloquium: Prof. Peter Gorham, Department of Physics and Astronomy, University of Hawaii - Manoa to speak on "A Search For Signatures of Dark Matter in Ultra-high Precision VLBI Astrometry."

Abstract:
We report on work in progress to investigate possible astrometric microlensing of quasars observed with Very Long Baseline Interferomety (VLBI). These astrometric data, obtained via thousands of individual observations, span up to 30 years, with astrometric precisions of a few tens of microarcseconds in many cases. Dark matter, whether in the form of isolated compact objects or distributed halos of exotic particles, is almost certain to lead to microlensing of distant sources, and such microlensing has probably already been observed as brightness variations in some cases. Here we look at a complementary effect, the astrometric changes caused by the image distortions of the microlenses, which may have a unique sensitivity to dark matter, regardless of its nature or origin.


Ticket Information
Free

Event Sponsor
Physics and Astronomy, Mānoa Campus

More Information
Dr. Peter Gorham, 956-9157, gorham@phys.hawaii.edu, http://www.phys.hawaii.edu/indico/conferenceDisplay.py?confId=334

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