English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The Extragalactic Lens VLBI Imaging Survey (ELVIS) searches for centralimages of lensed radio quasars, in order to measure the central densityprofiles of distant galaxies. Here we present sensitive multi-epoch Very LongBaseline Array (VLBA) observations of PMN J1838-3427 at 8 GHz, with a 1 sigmanoise level of 38 microJy beam^(-1). Based on the absence of a central image ofthe background source at this level, we explore the possibilities for thecentral matter distribution in the lens galaxy. A power-law density profile,rho ~ r^(-gamma), must have gamma > 1.93. Thus the density profile is close toan isothermal profile (gamma = 2) or steeper. The upper limit on anyconstant-density core in an otherwise isothermal profile is ~< 5 parsecs. Wealso derive the constraints on models in which the density profile isisothermal on kiloparsec scales, but is allowed to have a different power lawin the central ~100 parsecs. If the lens galaxy harbors a supermassive blackhole, the galaxy profile is allowed to be shallower, but for the expected blackhole mass the galaxy profile must still be close to isothermal or steeper.Comment: accepted to ApJ. 8 pages, 6 figures, 3 tables, uses \emulateap

The Extragalactic Lens VLBI Imaging Survey (ELVIS). I. A Search for the Central Image in the Gravitational Lens PMN J1838−3427