Publication

Microlensing & scintillation of gravitationally lensed compact radio sources: Evidence for MACHOs?

Koopmans, LVE. & de Bruyn, AG., 2001, GRAVITATIONAL LENSING: RECENT PROGRESS AND FUTURE GOALS. Brainerd, TG. & Kochanek, CS. (eds.). SAN FRANCISCO: ASTRONOMICAL SOC PACIFIC, p. 193-196 4 p. (ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES; vol. 237).

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

We present the first unambiguous case of external variability of an extra-galactic radio source, the CLASS gravitational lens B1600+434, consisting of two images lensed by an edge-on disk galaxy. The VLA 8.5-GHz difference light curve of the lens images shows external variability at the 14.6-sigma confidence level. Although the current single-frequency VLA observations cannot conclusively exclude scintillation, several lines of evidence show that it does not dominate the short-term variability. This is supported by an ongoing three-frequency WSRT campaign. If scintillation is the dominant source of this external variability, it would require very different properties of the Galactic ionized ISM towards the two lens images. Microlensing of a superluminal jet component can explain both the rms and time-scale of variability, but requires the halo of the lens galaxy to be filled with greater than or similar to0.5-M-circle dot MACHOs. The current data appear to support microlensing as the dominant source of the observed external variability.

Original languageEnglish
Title of host publicationGRAVITATIONAL LENSING: RECENT PROGRESS AND FUTURE GOALS
EditorsTG Brainerd, CS Kochanek
Place of PublicationSAN FRANCISCO
PublisherASTRONOMICAL SOC PACIFIC
Pages193-196
Number of pages4
ISBN (Print)1-58381-074-9
Publication statusPublished - 2001
EventConference on Gravitational Lensing - Recent Progress and Future Goals - , Morocco
Duration: 25-Jul-199930-Jul-1999

Publication series

NameASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES
PublisherASTRONOMICAL SOC PACIFIC
Volume237

Other

OtherConference on Gravitational Lensing - Recent Progress and Future Goals
CountryMorocco
Period25/07/199930/07/1999

Event

Conference on Gravitational Lensing - Recent Progress and Future Goals

25/07/199930/07/1999

Morocco

Event: Other

    Keywords

  • INTERSTELLAR

ID: 4016508