Published September 20, 2014 | Version Published
Journal Article Open

A Geometrically Supported z ~ 10 Candidate Multiply Imaged by the Hubble Frontier Fields Cluster A2744

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Johns Hopkins University
  • 3. ROR icon University of the Basque Country
  • 4. ROR icon Ikerbasque
  • 5. ROR icon Siena College
  • 6. ROR icon University of Hong Kong
  • 7. ROR icon CEA Saclay
  • 8. ROR icon University of Science and Technology of China
  • 9. ROR icon Institute of Physics of Cantabria
  • 10. ROR icon Pontificia Universidad Católica de Chile
  • 11. ROR icon Space Science Institute
  • 12. ROR icon Carnegie Observatories
  • 13. ROR icon Instituto de Astrofísica de Andalucía

Abstract

The deflection angles of lensed sources increase with their distance behind a given lens. We utilize this geometric effect to corroborate the z_phot ≃ 9.8 photometric redshift estimate of a faint near-IR dropout, triply imaged by the massive galaxy cluster A2744 in deep Hubble Frontier Fields images. The multiple images of this source follow the same symmetry as other nearby sets of multiple images that bracket the critical curves and have well-defined redshifts (up to z_spec ≃ 3.6), but with larger deflection angles, indicating that this source must lie at a higher redshift. Similarly, our different parametric and non-parametric lens models all require this object be at z ≳ 4, with at least 95% confidence, thoroughly excluding the possibility of lower-redshift interlopers. To study the properties of this source, we correct the two brighter images for their magnifications, leading to a star formation rate of ~0.3 M_☉ yr^(−1), a stellar mass of ~4 × 10^7 M_☉, and an age of ≲220 Myr (95% confidence). The intrinsic apparent magnitude is 29.9 AB (F160W), and the rest-frame UV (~1500 Å) absolute magnitude is M_UV, AB = −17.6. This corresponds to ~0.1 L*_(z=8) (~0.2 L*_(z=10), adopting dM*/dz ~ 0.45), making this candidate one of the least luminous galaxies discovered at z ~ 10.

Additional Information

© 2014 The American Astronomical Society. Received 2014 July 14; accepted 2014 August 23; published 2014 September 4. We kindly thank the anonymous reviewer of this work for useful comments. Useful discussions with Rychard Bouwens, Richard Ellis, and Larry Bradley are much appreciated. This work is based on observations made with the NASA/ ESA Hubble Space Telescope and was supported by award AR-13079 from the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. It is also based on observations from the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This work utilizes gravitational lensing models produced by P.I.s Zitrin and Merten, and P.I. Ebeling, funded as part of the HST Frontier Fields program conducted by STScI. Support for this work was provided by NASA through Hubble Fellowship grant #HST-HF-51334.01-A awarded by STScI.

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Additional details

Identifiers

Eprint ID
50174
Resolver ID
CaltechAUTHORS:20141002-133453349

Funding

Space Telescope Science Institute
AR-13079
NASA
NAS 5-26555
NASA Hubble Fellowship
HST-HF-51334.01-A

Dates

Created
2014-10-06
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field