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Title: A very large ( θ E ≳ 40") strong gravitational lens selected with the Sunyaev–Zel’dovich effect: PLCK G287.0+32.9 ( z = 0.38)

Since galaxy clusters sit at the high end of the mass function, the number of galaxy clusters both massive and concentrated enough to yield particularly large Einstein radii poses useful constraints on cosmological and structure formation models. To date, less than a handful of clusters are known to have Einstein radii exceeding $$\sim 40^{\prime\prime} $$ (for a source at $${z}_{s}\simeq 2$$, nominally). Here, we report an addition to that list of the Sunyaev–Zel'dovich (SZ) selected cluster, PLCK G287.0+32.9 (z = 0.38), the second-highest SZ-mass (M 500) cluster from the Planck catalog. We present the first strong-lensing analysis of the cluster, identifying 20 sets of multiply imaged galaxies and candidates in new Hubble Space Telescope ( HST) data, including a long, $$l\sim 22^{\prime\prime} $$ giant arc, as well as a quadruply imaged, apparently bright (magnified to $${J}_{{\rm{F}}110{\rm{W}}}=25.3$$ AB), likely high-redshift dropout galaxy at $${z}_{\mathrm{phot}}=6.90$$ [6.13–8.43] (95% C.I.). Our analysis reveals a very large critical area (1.55 arcmin2, $${z}_{s}\simeq 2$$), corresponding to an effective Einstein radius of $${\theta }_{{\rm{E}}}\sim 42^{\prime\prime} $$. Furthermore, the model suggests the critical area will expand to 2.58 arcmin2 ($${\theta }_{{\rm{E}}}\sim 54^{\prime\prime} $$) for sources at $${z}_{s}\sim 10$$. Our work adds to recent efforts to model very massive clusters toward the launch of the James Webb Space Telescope, in order to identify the most useful cosmic lenses for studying the early universe. Spectroscopic redshifts for the multiply imaged galaxies and additional HST data will be necessary for refining the lens model and verifying the nature of the $$z\sim 7$$ dropout.
ORCiD logo [1] ; ORCiD logo [2] ;  [2] ; ORCiD logo [3] ;  [4] ; ORCiD logo [5] ; ORCiD logo [6] ; ORCiD logo [7] ;  [2] ;  [8]
  1. Ben-Gurion Univ. of the Negev, Be'er-Sheva (Israel)
  2. Univ. Observatory Munich, Munich (Germany); Max Planck Institute for Extraterrestrial Physics, Garching (Germany)
  3. Space Telescope Science Institute, Baltimore, MD (United States)
  4. INAF - Osservatorio Astronomico di Trieste, Trieste (Italy)
  5. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
  6. Univ. Observatory Munich, Munich (Germany); INAF - Osservatorio Astronomico di Trieste, Trieste (Italy)
  7. INAF - Osservatorio Astronomico di Trieste, Trieste (Italy); Univ. degli Studi di Trieste, Trieste (Italy)
  8. INAF - Osservatorio Astronomico di Capodimonte, Napoli (Italy)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
The Astrophysical Journal. Letters
Additional Journal Information:
Journal Volume: 839; Journal Issue: 1; Journal ID: ISSN 2041-8213
Institute of Physics (IOP)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; galaxies: clusters: general; galaxies: clusters: individual (PLCK G287.0+32.9); gravitational lensing; strong
OSTI Identifier: