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Title: A calibration of the stellar mass fundamental plane at z ∼ 0.5 using the micro-lensing-induced flux ratio anomalies of macro-lensed quasars {sup ,} {sup ,}

We measure the stellar mass surface densities of early-type galaxies by observing the micro-lensing of macro-lensed quasars caused by individual stars, including stellar remnants, brown dwarfs, and red dwarfs too faint to produce photometric or spectroscopic signatures. Instead of observing multiple micro-lensing events in a single system, we combine single-epoch X-ray snapshots of 10 quadruple systems, and compare the measured relative magnifications for the images with those computed from macro-models. We use these to normalize a stellar mass fundamental plane constructed using a Salpeter initial mass function with a low-mass cutoff of 0.1 M {sub ☉} and treat the zeropoint of the surface mass density as a free parameter. Our method measures the graininess of the gravitational potential produced by individual stars, in contrast to methods that decompose a smooth total gravitational potential into two smooth components, one stellar and one dark. We find the median likelihood value for the normalization factor F by which the Salpeter stellar masses must be multiplied is 1.23, with a one sigma confidence range, dominated by small number statistics, of 0.77
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States)
  2. Sam Houston State University, Huntsville, TX 77341 (United States)
  3. Areté Associates, Northridge, CA 91324 (United States)
  4. Zentrum für Astronomie der Universität Heidelberg, Heidelberg D-69120 (Germany)
Publication Date:
OSTI Identifier:
22370573
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 793; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALIBRATION; COMPARATIVE EVALUATIONS; DENSITY; DWARF STARS; GALAXIES; GRAVITATIONAL LENSES; IMAGES; MASS; PHOTOMETRY; QUASARS; RED DWARF STARS; SPECTROSCOPY; STARS; SUPERNOVA REMNANTS; SURFACES; X RADIATION