Separating galaxies from the cluster dark matter halo in Abell 611
Abstract
We investigate the mass content of galaxies in the core of the galaxy cluster Abell 611. We perform a strong lensing analysis of the cluster core and use velocity dispersion measurements for individual cluster members as additional constraints. Despite the small number of multiply-imaged systems and cluster members with central velocity dispersions available in the core of A611, the addition of velocity dispersion measurements leads to tighter constraints on the mass associated with the galaxy component, and as a result, on the mass associated with the dark matter halo. Without the spectroscopic velocity dispersions, we would overestimate the mass of the galaxy component by a factor of ∼1.5, or, equivalently, we would underestimate the mass of the cluster dark halo by ∼5 per cent. We perform an additional lensing analysis using surface brightness (SB) reconstruction of the tangential giant arc. This approach improves the constraints on the mass parameters of the five galaxies close to the arc by a factor up to ∼10. The resulting parameters are in good agreement with the σ-rtr scaling relation derived in the pointlike analysis. The galaxy velocity dispersions resulting from the SB analysis are consistent at the 1σ confidence level with the spectroscopic measurements. In contrast, the truncation radii for 2–3 galaxies depart significantly from the galaxy scaling relation and suggest differences in the stripping history from galaxy to galaxy.
Additional Information
© 2016. The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2016 November 21. Received 2016 November 18; in original form 2016 February 26. We thank Andrew Newman and David Sand for generously providing their Hectospec spectra of A611 so that we could extract central velocity dispersions of additional cluster members. We also thank Aleksi Halkola, who provided the tool glee used to perform this analysis. Finally, we thank Megan Donahue, Brenda Frye, Claudio Grillo and Massimo Meneghetti for their comments and contributions to this work. This work is supported by the Transregional Collaborative Research Centre TRR 33 – The Dark Universe and the DFG cluster of excellence 'Origin and Structure of the Universe'. The CLASH Multi-Cycle Treasury Program (GO-12065) is based on observations made with the NASA/ESA Hubble Space Telescope. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. The Dark Cosmology Centre is funded by the DNRF. Support for AZ is provided by NASA through Hubble Fellowship grant #HST-HF-51334.01-A awarded by STScI. The Smithsonian Institution supports the research of DGF, MJG and HSH.Attached Files
Published - stw3048.pdf
Submitted - 1602.08491.pdf
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Additional details
- Eprint ID
- 75589
- Resolver ID
- CaltechAUTHORS:20170331-120249409
- TRR 33
- Deutsche Forschungsgemeinschaft (DFG)
- NAS 5-26555
- NASA
- Danish National Research Foundation
- HST-HF-51334.01-A
- NASA Hubble Fellowship
- Smithsonian Institution
- Created
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2017-03-31Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field