Volume 594, October 2016
|Number of page(s)||14|
|Section||Cosmology (including clusters of galaxies)|
|Published online||24 October 2016|
The Bullet cluster at its best: weighing stars, gas, and dark matter
1 Laboratoire d’Astrophysique École Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
2 Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 13388 Marseille, France
3 Univ. Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon, UMR 5574, 69230 Saint-Genis-Laval, France
4 Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899, USA
Received: 14 December 2015
Accepted: 11 August 2016
Aims. We present a new strong lensing mass reconstruction of the Bullet cluster (1E 0657-56) at z = 0.296, based on WFC3 and ACS HST imaging and VLT/FORS2 spectroscopy. The strong lensing constraints underwent substantial revision compared to previously published analysis, there are now 14 (six new and eight previously known) multiply-imaged systems, of which three have spectroscopically confirmed redshifts (including one newly measured from this work).
Methods. The reconstructed mass distribution explicitly included the combination of three mass components: (i) the intra-cluster gas mass derived from X-ray observation; (ii) the cluster galaxies modeled by their fundamental plane scaling relations and (iii) dark matter.
Results. The model that includes the intra-cluster gas is the one with the best Bayesian evidence. This model has a total rms value of 0.158″ between the predicted and measured image positions for the 14 multiple images considered. The proximity of the total rms to resolution of HST/WFC3 and ACS (0.07−0.15′′FWHM) demonstrates the excellent precision of our mass model. The derived mass model confirms the spatial offset between the X-ray gas and dark matter peaks. The fraction of the galaxy halos mass to total mass is found to be fs = 11 ± 5% for a total mass of 2.5 ± 0.1 × 1014M⊙ within a 250 kpc radial aperture.
Key words: gravitational lensing: strong / galaxies: clusters: individual: Bullet cluster
© ESO, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.