The Astrophysical Journal Letters (Jan 2023)
Two Lensed Star Candidates at z ≃ 4.8 behind the Galaxy Cluster MACS J0647.7+7015
- Ashish Kumar Meena,
- Adi Zitrin,
- Yolanda Jiménez-Teja,
- Erik Zackrisson,
- Wenlei Chen,
- Dan Coe,
- Jose M. Diego,
- Paola Dimauro,
- Lukas J. Furtak,
- Patrick L. Kelly,
- Masamune Oguri,
- Brian Welch,
- Abdurro’uf,
- Felipe Andrade-Santos,
- Angela Adamo,
- Rachana Bhatawdekar,
- Maruša Bradač,
- Larry D. Bradley,
- Tom Broadhurst,
- Christopher J. Conselice,
- Pratika Dayal,
- Megan Donahue,
- Brenda L. Frye,
- Seiji Fujimoto,
- Tiger Yu-Yang Hsiao,
- Vasily Kokorev,
- Guillaume Mahler,
- Eros Vanzella,
- Rogier A. Windhorst
Affiliations
- Ashish Kumar Meena
- ORCiD
- Physics Department, Ben-Gurion University of the Negev , P.O. Box 653, Be’er-Sheva 84105, Israel ; [email protected]
- Adi Zitrin
- ORCiD
- Physics Department, Ben-Gurion University of the Negev , P.O. Box 653, Be’er-Sheva 84105, Israel ; [email protected]
- Yolanda Jiménez-Teja
- ORCiD
- Instituto de Astrofísica de Andalucía , Glorieta de la Astronomía s/n, E-18008 Granada, Spain; Observatório Nacional—MCTI (ON) , Rua Gal. José Cristino 77, São Cristóvão, 20921-400, Rio de Janeiro, Brazil
- Erik Zackrisson
- ORCiD
- Observational Astrophysics, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20 Uppsala, Sweden
- Wenlei Chen
- ORCiD
- School of Physics and Astronomy, University of Minnesota , 116 Church Street SE, Minneapolis, MN, 55455, USA
- Dan Coe
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD, 21218, USA; Association of Universities for Research in Astronomy (AURA) for the European Space Agency (ESA) , STScI, Baltimore, MD, USA; Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 N Charles St. Baltimore, MD, 21218, USA
- Jose M. Diego
- ORCiD
- Instituto de Física de Cantabria (CSIC-UC). Avda. Los Castros s/n. E-39005 Santander, Spain
- Paola Dimauro
- ORCiD
- INAF—Osservatorio Astronomico di Roma , via di Frascati 33, I-00078 Monte Porzio Catone, Italy
- Lukas J. Furtak
- ORCiD
- Physics Department, Ben-Gurion University of the Negev , P.O. Box 653, Be’er-Sheva 84105, Israel ; [email protected]
- Patrick L. Kelly
- ORCiD
- School of Physics and Astronomy, University of Minnesota , 116 Church Street SE, Minneapolis, MN, 55455, USA
- Masamune Oguri
- ORCiD
- Center for Frontier Science, Chiba University , 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan; Department of Physics, Graduate School of Science, Chiba University , 1-33 Yayoi-Cho, Inage-Ku, Chiba 263-8522, Japan
- Brian Welch
- ORCiD
- Department of Astronomy, University of Maryland , College Park, MD, 20742, USA; Observational Cosmology Lab, NASA Goddard Space Flight Center , Greenbelt, MD, 20771, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD, 20771, USA
- Abdurro’uf
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD, 21218, USA; Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 N Charles St. Baltimore, MD, 21218, USA
- Felipe Andrade-Santos
- ORCiD
- Department of Liberal Arts and Sciences, Berklee College of Music , 7 Haviland Street, Boston, MA, 02215, USA; Center for Astrophysics Harvard & Smithsonian , 60 Garden Street, Cambridge, MA, 02138, USA
- Angela Adamo
- ORCiD
- Department of Astronomy, Oskar Klein Centre, Stockholm University , AlbaNova University Centre, SE-106 91 Stockholm, Sweden
- Rachana Bhatawdekar
- ORCiD
- European Space Agency , ESA/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
- Maruša Bradač
- ORCiD
- Department of Mathematics and Physics, University of Ljubljana , Jadranska ulica 19, SI-1000 Ljubljana, Slovenia; Department of Physics and Astronomy, University of California , Davis, 1 Shields Ave, Davis, CA, 95616, USA
- Larry D. Bradley
- ORCiD
- Space Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD, 21218, USA
- Tom Broadhurst
- ORCiD
- Department of Theoretical Physics, University of the Basque Country UPV/EHU , Bilbao, Spain; Donostia International Physics Center (DIPC) , E-20018 Donostia, Spain; IKERBASQUE, Basque Foundation for Science , Bilbao, Spain
- Christopher J. Conselice
- ORCiD
- Jodrell Bank Centre for Astrophysics, University of Manchester , Oxford Road, Manchester, UK
- Pratika Dayal
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , P.O. Box 800, 9700 AV Groningen, The Netherlands
- Megan Donahue
- ORCiD
- Michigan State University , Physics & Astronomy Department, East Lansing, MI, USA
- Brenda L. Frye
- ORCiD
- Department of Astronomy/Steward Observatory, University of Arizona , 933 N. Cherry Avenue, Tucson, AZ, 85721, USA
- Seiji Fujimoto
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, 78712, USA
- Tiger Yu-Yang Hsiao
- ORCiD
- Center for Astrophysical Sciences, Department of Physics and Astronomy, The Johns Hopkins University , 3400 N Charles St. Baltimore, MD, 21218, USA
- Vasily Kokorev
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , PO Box 800, 9700 AV Groningen, The Netherlands
- Guillaume Mahler
- ORCiD
- Centre for Extragalactic Astronomy, Durham University , South Road, Durham, DH1 3LE, UK; Institute for Computational Cosmology, Durham University , South Road, Durham, DH1 3LE, UK
- Eros Vanzella
- ORCiD
- INAF—OAS, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna , via Gobetti 93/3, I-40129 Bologna, Italy
- Rogier A. Windhorst
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ, 85287-1404, USA
- DOI
- https://doi.org/10.3847/2041-8213/acb645
- Journal volume & issue
-
Vol. 944,
no. 1
p. L6
Abstract
We report the discovery of two extremely magnified lensed star candidates behind the galaxy cluster MACS J0647.7+015 using recent multiband James Webb Space Telescope (JWST) NIRCam observations. The star candidates are seen in a previously known, z _phot ≃ 4.8 dropout giant arc that straddles the critical curve. The candidates lie near the expected critical curve position, but lack clear counter-images on the other side of it, suggesting these are possibly stars undergoing caustic crossings. We present revised lensing models for the cluster, including multiply imaged galaxies newly identified in the JWST data, and use them to estimate background macro-magnifications of at least ≳90 and ≳50 at the positions of the two candidates, respectively. With these values, we expect effective, caustic-crossing magnifications of ∼[10 ^3 –10 ^5 ] for the two star candidates. The spectral energy distributions of the two candidates match well the spectra of B-type stars with best-fit surface temperatures of ∼10,000 K, and ∼12,000 K, respectively, and we show that such stars with masses ≳20 M _⊙ and ≳50 M _⊙ , respectively, can become sufficiently magnified to be observable. We briefly discuss other alternative explanations and conclude that these objects are likely lensed stars, but also acknowledge that the less-magnified candidate may alternatively reside in a star cluster. These star candidates constitute the second highest-redshift examples to date after Earendel at z _phot ≃ 6.2, establishing further the potential of studying extremely magnified stars at high redshifts with JWST. Planned future observations, including with NIRSpec, will enable a more detailed view of these candidates in the near future.
Keywords
