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BUFFALO/Flashlights: Constraints on the abundance of lensed supergiant stars in the Spock galaxy at redshift 1

Authors :
Diego, Jose M
Li, Sung Kei
Meena, Ashish K
Niemiec, Anna
Acebron, Ana
Jauzac, Mathilde
Struble, Mitchell F
Amruth, Alfred
Broadhurst, Tom J
Cerny, Catherine
Ebeling, Harald
Filippenko, Alexei V
Jullo, Eric
Kelly, Patrick
Koekemoer, Anton M
Lagatutta, David
Lim, Jeremy
Limousin, Marceau
Mahler, Guillaume
Patel, Nency
Remolina, Juan
Richard, Johan
Sharon, Keren
Steinhardt, Charles
Umetsu, Keichii
Williams, Liliya
Zitrin, Adi
Palencia, J.M
Dai, Liang
Ji, Lingyuan
Pascale, Massimo
Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585))
Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Laboratoire d'Astrophysique de Marseille (LAM)
Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Centre de Recherche Astrophysique de Lyon (CRAL)
École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)
Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Publication Year :
2023

Abstract

We present a constraint on the abundance of supergiant (SG) stars at redshift z approx. 1, based on recent observations of a strongly lensed arc at this redshift. First we derive a free-form model of MACS J0416.1-2403 using data from the BUFFALO program. The new lens model is based on 72 multiply lensed galaxies that produce 214 multiple images, making it the largest sample of spectroscopically confirmed lensed galaxies on this cluster. The larger coverage in BUFFALO allows us to measure the shear up to the outskirts of the cluster, and extend the range of lensing constraints up to ~ 1 Mpc from the central region, providing a mass estimate up to this radius. As an application, we make predictions for the number of high-redshift multiply-lensed galaxies detected in future observations with JWST. Then we focus on a previously known lensed galaxy at z=1.0054, nicknamed Spock, which contains four previously reported transients. We interpret these transients as microcaustic crossings of SG stars and compute the probability of such events. Based on simplifications regarding the stellar evolution, we find that microlensing (by stars in the intracluster medium) of SG stars at z=1.0054 can fully explain these events. The inferred abundance of SG stars is consistent with either (1) a number density of stars with bolometric luminosities beyond the Humphreys-Davidson (HD) limit (L ~ $6\times10^5 L_{\odot}$) that is below 400 stars per sq. kpc, or (2) the absence of stars beyond the HD limit but with a SG number density of ~ 9000 per sq. kpc for stars with luminosities between $10^5$ and $6\times10^5$. This is equivalent to one SG star per 10x10 pc$^2$. We finally make predictions for future observations with JWST's NIRcam. We find that in observations made with the F200W filter that reach 29 mag AB, if cool red SG stars exist at z~1 beyond the HD limit, they should be easily detected in this arc<br />24 pages & 18 figures

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....0b00c210f02632301f01402572d226c1