COOL-LAMPS. VI. Lens Model and New Constraints on the Properties of COOL J1241+2219, a Bright z = 5 Lyman Break Galaxy and its z = 1 Cluster Lens

Klein, Maxwell; Sharon, Keren; Napier, Kate; Gladders, Michael D.; Khullar, Gourav; Bayliss, Matthew; Dahle, Håkon; Owens, M. Riley; Stark, Antony; Brownsberger, Sasha; Kim, Keunho J.; Kuchta, Nicole; Mahler, Guillaume; Smith, Grace; Walker, Ryan; Gozman, Katya; Martinez, Michael N.; Matthews Acuña, Owen S.; Merz, Kaiya; Sanchez, Jorge A.; Stein, Daniel J. Kavin; Sukay, Ezra O.; Tavangar, Kiyan

Abstract

We present a strong lensing analysis of COOL J1241+2219, the brightest known gravitationally lensed galaxy at z ≥ 5, based on new multiband Hubble Space Telescope (HST) imaging data. The lensed galaxy has a redshift of z = 5.043, placing it shortly after the end of the “Epoch of Reionization,” and an AB magnitude z AB = 20.47 mag (Khullar et al.). As such, it serves as a touchstone for future research of that epoch. The high spatial resolution of HST reveals internal structure in the giant arc, from which we identify 15 constraints and construct a robust lens model. We use the lens model to extract the cluster mass and lensing magnification. We find that the mass enclosed within the Einstein radius of the z = 1.001 cluster lens is M(<5.″77)=1.079−0.007+0.023×1013M☉ , significantly lower than other known strong lensing clusters at its redshift. The average magnification of the giant arc is 〈μ arc〉 = 76−20+40 , a factor of 2.4−0.7+1.4 greater than previously estimated from ground-based data; the flux-weighted average magnification is 〈μ arc〉 = 92−31+37 . We update the current measurements of the stellar mass and star formation rate (SFR) of the source for the revised magnification to log(M⋆/M⊙)= 9.7 ± 0.3 and SFR = 10.3−4.4+7.0 M ⊙ yr−1, respectively. The powerful lensing magnification acting upon COOL J1241+2219 resolves the source and enables future studies of the properties of its star formation on a clump-by-clump basis. The lensing analysis presented here will support upcoming multiwavelength characterization with HST and JWST data of the stellar mass assembly and physical properties of this high-redshift lensed galaxy.

Citation

Klein, M., Sharon, K., Napier, K., Gladders, M. D., Khullar, G., Bayliss, M., Dahle, H., Owens, M. R., Stark, A., Brownsberger, S., Kim, K. J., Kuchta, N., Mahler, G., Smith, G., Walker, R., Gozman, K., Martinez, M. N., Matthews Acuña, O. S., Merz, K., Sanchez, J. A., …Tavangar, K. (2024). COOL-LAMPS. VI. Lens Model and New Constraints on the Properties of COOL J1241+2219, a Bright z = 5 Lyman Break Galaxy and its z = 1 Cluster Lens. Astrophysical Journal, 963(1), Article 44. https://doi.org/10.3847/1538-4357/ad22de

• Journal Article Type: Article
• Acceptance Date: Jan 24, 2024
• Online Publication Date: Feb 28, 2024
• Publication Date: Mar 1, 2024
• Deposit Date: Apr 10, 2024
• Publicly Available Date: Apr 10, 2024
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 963
• Issue: 1
• Article Number: 44
• DOI: https://doi.org/10.3847/1538-4357/ad22de
• Keywords: Galaxy formation, Gravitational lensing, Galaxy clusters, Strong gravitational lensing
• Public URL: https://durham-repository.worktribe.com/output/2292467