BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//icalcreate//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
SUMMARY:EVN Seminar: John McKean on testing models for dark matter with gr
 avitational lenses
DTSTART:20260312T100000Z
DTEND:20260312T110000Z
DTSTAMP:20260226T131757Z
UID:d627b58b-b3e0-4d2d-9d08-842f4e4a1289@icalcreate
DESCRIPTION:EVN Seminar: John McKean on testing models for dark matter wit
 h gravitational lenses\n\n\nJoin via Zoom (Meeting ID: 876 4980 9023\; htt
 ps://astron.zoom.us/j/87649809023) or via the YouTube streaming in the JIV
 E and EVN channel (https://youtube.com/live/KArulZlk46A). More information
  at https://evlbi.org/evn-seminars. Abstract: Gravitational lensing provid
 es a powerful probe of the global mass properties of galaxies\, which are 
 best tested using observations at extremely high angular resolution. In ad
 dition\, through detailed observations of the lensed images\, it is possib
 le to place tight constraints on the nature of dark matter through measuri
 ng the abundance and properties of low mass haloes in the Universe via the
 ir subtle gravitational lensing signal. Here\, we first present new observ
 ations with the VLA and HSA to better understand the source of so-called f
 lux-ratio anomalies in four image gravitational lenses\, which historicall
 y provided the first constraints on CDM using lensing studies. Next\, we w
 ill present the analysis of the mass properties of five massive elliptical
  galaxies at intermediate redshifts\, by combining gravitational lensing a
 nd the sensitivity and resolving power of the Atacama Large Millimetre Arr
 ay (ALMA) and global Very Long Baseline Interferometry (radio VLBI). Using
  imaging at 25 to a few milli-arcsecond resolution\, we find that complex 
 mass models with angular structure are strongly favoured by the data. In a
 ddition\, such observations are sensitive to small-scale structure either 
 in the lens or along the line-of-sight to the background source. From such
  an analysis of the data from global VLBI observations\, we detect of a lo
 w mass (million solar mass) dark object\, whose properties are inconsisten
 t with a dark matter halo from either cold or warm dark matter models\, bu
 t may be in agreement with more exotic models\, like self-interacting dark
  matter. Finally\, we present a brief overview of future studies using the
  SKA and a likely African VLBI facility.
LOCATION:https://astron.zoom.us/j/87649809023
URL:https://www.evlbi.org/evn-seminars
BEGIN:VALARM
ACTION:DISPLAY
DESCRIPTION:Reminder: EVN Seminar: John McKean on testing models for dark 
 matter with gravitational lenses
TRIGGER:-PT15M
END:VALARM
END:VEVENT
END:VCALENDAR