The Cosmic Telescope that Lenses the Sunburst Arc, PSZ1 G311.65-18.48: Strong Gravitational Lensing model and Source Plane Analysis
Published in The Astrophysical Journal, 2022
We present a strong-lensing analysis of the cluster PSZ1 G311.65−18.48, based on Hubble Space Telescope imaging, archival VLT/MUSE spectroscopy, and Chandra X-ray data. This cool-core cluster (z = 0.443) lenses the brightest lensed galaxy known, dubbed the “Sunburst Arc” (z = 2.3703), a Lyman continuum (LyC) emitting galaxy multiply imaged 12 times. We identify in this field 14 additional strongly lensed galaxies to constrain a strong-lens model and report secure spectroscopic redshifts of four of them. We measure a projected cluster core mass of M(<250 kpc) = \(2.93^{0.01}_{-0.02} \times 10^14 M_{\odot}\). The two least magnified but complete images of the Sunburst Arc’s source galaxy are magnified by ∼13×, while the LyC clump is magnified by ∼4–80×. We present time delay predictions and conclusive evidence that a discrepant clump in the Sunburst Arc, previously claimed to be a transient, is not variable, thus strengthening the hypothesis that it results from an exceptionally high magnification. A source plane reconstruction and analysis of the Sunburst Arc finds its physical size to be 1 × 2 kpc and that it is resolved in three distinct directions in the source plane, 0°, 40°, and 75° (east of north). We place an upper limit of r \(\lesssim\) 50 pc on the source plane size of unresolved clumps and r \(\lesssim\) 32 pc for the LyC clump. Finally, we report that the Sunburst Arc is likely in a system of two or more galaxies separated by \(\lesssim\)6 kpc in projection. Their interaction may drive star formation and could play a role in the mechanism responsible for the leaking LyC radiation
Recommended citation: Sharon, K., Mahler, G., Rivera-Thorsen, T. E., Dahle, H., Gladders, M. D., Bayliss, M. B., Florian, M. K., Kim, K. J., Khullar, G., Mainali, R., Napier, K. A., Navarre, A., Rigby, J. R., Remolina González, J. D., & Sharma, S. (2022). The Cosmic Telescope That Lenses the Sunburst Arc, PSZ1 G311.65-18.48: Strong Gravitational Lensing Model and Source Plane Analysis. \apj, 941(2), e203. https://doi.org/10.3847/1538-4357/ac927a
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