TY - JOUR
T1 - BUFFALO/Flashlights
T2 - Constraints on the abundance of lensed supergiant stars in the Spock galaxy at redshift 1
AU - Diego, Jose M.
AU - Li, Sung Kei
AU - Meena, Ashish K.
AU - Niemiec, Anna
AU - Acebron, Ana
AU - Jauzac, Mathilde
AU - Struble, Mitchell F.
AU - Amruth, Alfred
AU - Broadhurst, Tom J.
AU - Cerny, Catherine
AU - Ebeling, Harald
AU - Filippenko, Alexei V.
AU - Jullo, Eric
AU - Kelly, Patrick
AU - Koekemoer, Anton M.
AU - Lagattuta, David
AU - Lim, Jeremy
AU - Limousin, Marceau
AU - Mahler, Guillaume
AU - Patel, Nency
AU - Remolina, Juan
AU - Richard, Johan
AU - Sharon, Keren
AU - Steinhardt, Charles
AU - Umetsu, Keiichi
AU - Williams, Liliya
AU - Zitrin, Adi
AU - Palencia, Jose María
AU - Dai, Liang
AU - Ji, Lingyuan
AU - Pascale, Massimo
N1 - Publisher Copyright:
© The Authors 2024.
PY - 2024/1/1
Y1 - 2024/1/1
N2 - In this work, we present a constraint on the abundance of supergiant (SG) stars at redshift z ≈ 1, based on recent observations of a strongly lensed arc at this redshift. First we derived a free-form model of MACS J0416.1-2403 using data from the Beyond Ultradeep Frontier Fields and Legacy Observations (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 allowed 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 the James Webb Space Telescope (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 explain how we computed 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 (Lmax ≈ 6 × 105 L⊙ for red stars), which is below ∼400 stars kpc-2, or (2) the absence of stars beyond the HD limit but with a SG number density of ∼9000 kpc-2 for stars with luminosities between 105 L⊙ and 6 × 105 L⊙. This is equivalent to one SG star per 10 × 10 pc2. Finally, we 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.
AB - In this work, we present a constraint on the abundance of supergiant (SG) stars at redshift z ≈ 1, based on recent observations of a strongly lensed arc at this redshift. First we derived a free-form model of MACS J0416.1-2403 using data from the Beyond Ultradeep Frontier Fields and Legacy Observations (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 allowed 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 the James Webb Space Telescope (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 explain how we computed 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 (Lmax ≈ 6 × 105 L⊙ for red stars), which is below ∼400 stars kpc-2, or (2) the absence of stars beyond the HD limit but with a SG number density of ∼9000 kpc-2 for stars with luminosities between 105 L⊙ and 6 × 105 L⊙. This is equivalent to one SG star per 10 × 10 pc2. Finally, we 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.
KW - Gravitation
KW - Gravitational lensing: strong
KW - Supergiants
UR - http://www.scopus.com/inward/record.url?scp=85184275459&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202346761
DO - 10.1051/0004-6361/202346761
M3 - Article
AN - SCOPUS:85184275459
SN - 0004-6361
VL - 681
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A124
ER -