The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies

Brenda L. Frye, Massimo Pascale, Nicholas Foo, Reagen Leimbach, Nikhil Garuda, Paulina Soto Robles, Jake Summers, Carlos Diaz, Patrick Kamieneski, Lukas J. Furtak, Seth H. Cohen, Jose Diego, Benjamin Beauchesne, Rogier A. Windhorst, S. P. Willner, Anton M. Koekemoer, Adi Zitrin, Gabriel Caminha, Karina I. Caputi, Dan CoeChristopher J. Conselice, Liang Dai, Hervé Dole, Simon P. Driver, Norman A. Grogin, Kevin Harrington, Rolf A. Jansen, Jean Paul Kneib, Matt Lehnert, James Lowenthal, Madeline A. Marshall, Felipe Menanteau, Belén Alcalde Pampliega, Nor Pirzkal, Mari Polletta, Johan Richard, Aaron Robotham, Russell E. Ryan, Michael J. Rutkowski, Christóbal Sifón, Scott Tompkins, Daniel Wang, Haojing Yan, Min S. Yun

Research output: Contribution to journalArticlepeer-review


The massive galaxy cluster El Gordo (z = 0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the “Prime Extragalactic Areas for Reionization and Lensing Science” (“PEARLS”) program. Point-spread function-matched photometry across Hubble Space Telescope and NIRCam filters supplies new photometric redshifts. A new light-traces-mass lens model based on 56 image multiplicities identifies the two mass peaks and yields a mass estimate within 500 kpc of (7.0 ± 0.30) × 1014 M . A search for substructure in the 140 cluster members with spectroscopic redshifts confirms the two main mass components. The southeastern mass peak that contains the brightest cluster galaxy is more tightly bound than the northwestern one. The virial mass within 1.7 Mpc is (5.1 ± 0.60)×1014 M , lower than the lensing mass. A significant transverse velocity component could mean the virial mass is underestimated. We contribute one new member to the previously known z = 4.32 galaxy group. Intrinsic (delensed) positions of the five secure group members span a physical extent of ∼60 kpc. 13 additional candidates selected by spectroscopic/photometric constraints are small and faint, with a mean intrinsic luminosity ∼2.2 mag fainter than L *. NIRCam imaging admits a fairly wide range of brightnesses and morphologies for the group members, suggesting a more diverse galaxy population in this galaxy overdensity.

Original languageEnglish (US)
Article number81
JournalAstrophysical Journal
Issue number1
StatePublished - Jul 1 2023

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies'. Together they form a unique fingerprint.

Cite this