dorsal/arxiv
View SchemaCaught in Swallowtails: Discovery of Two Swallowtail Image Formations in MS 0451.6-0305
| Authors | Ashish K. Meena, Wenlei Chen, Lukas J. Furtak, Johan Richard, Adi Zitrin, Jose M. Diego, Mathilde Jauzac, Patrick L. Kelly, Rogier A. Windhorst |
|---|---|
| Categories | |
| ArXiv ID | 2601.10097vv1 |
| URL | https://arxiv.org/abs/2601.10097 |
| License | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
Abstract
We report the discovery of two swallowtail image formations at $z=2.91$ and $z=6.70$ behind the galaxy cluster MS 0451.6-0305 in JWST-NIRCam imaging. We find that in both of the above lensed systems, the complex image morphology cannot be reproduced by simple fold/cusp caustics, and detailed lens modeling reveals higher-order swallowtail caustic configurations. In the $z=2.91$ lens system, a small part of the source galaxy (which itself is part of a galaxy group) containing atleast two compact knots sits inside the swallowtail caustic, producing a quadruply imaged arc. At two of the image positions of these knots, we infer point source magnifications of $\gtrsim 300$, implying lensing-corrected effective radii of $\lesssim 0.8-1.5$ pc. The $z=6.70$ system exhibits even more complex image formation. We therefore only use the most confidently identified counter-images of knots in this system as constraints in our lens modeling. The resulting model predicts magnifications $\sim20-200$ and lensing-corrected effective radii of $\lesssim 0.8-18.5$ pc for various knots. Together, these two systems represent the first example of observations of multiple swallowtail image formations in a single galaxy cluster and demonstrate the ability of swallowtail caustics to magnify individual substructures at sub-parsec scales, from intermediate redshifts to the first billion years of the Universe.
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"abstract": "We report the discovery of two swallowtail image formations at $z=2.91$ and $z=6.70$ behind the galaxy cluster MS 0451.6-0305 in JWST-NIRCam imaging. We find that in both of the above lensed systems, the complex image morphology cannot be reproduced by simple fold/cusp caustics, and detailed lens modeling reveals higher-order swallowtail caustic configurations. In the $z=2.91$ lens system, a small part of the source galaxy (which itself is part of a galaxy group) containing atleast two compact knots sits inside the swallowtail caustic, producing a quadruply imaged arc. At two of the image positions of these knots, we infer point source magnifications of $\\gtrsim 300$, implying lensing-corrected effective radii of $\\lesssim 0.8-1.5$ pc. The $z=6.70$ system exhibits even more complex image formation. We therefore only use the most confidently identified counter-images of knots in this system as constraints in our lens modeling. The resulting model predicts magnifications $\\sim20-200$ and lensing-corrected effective radii of $\\lesssim 0.8-18.5$ pc for various knots. Together, these two systems represent the first example of observations of multiple swallowtail image formations in a single galaxy cluster and demonstrate the ability of swallowtail caustics to magnify individual substructures at sub-parsec scales, from intermediate redshifts to the first billion years of the Universe.",
"arxiv_id": "2601.10097",
"authors": [
"Ashish K. Meena",
"Wenlei Chen",
"Lukas J. Furtak",
"Johan Richard",
"Adi Zitrin",
"Jose M. Diego",
"Mathilde Jauzac",
"Patrick L. Kelly",
"Rogier A. Windhorst"
],
"categories": [
"astro-ph.GA"
],
"license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
"title": "Caught in Swallowtails: Discovery of Two Swallowtail Image Formations in MS 0451.6-0305",
"url": "https://arxiv.org/abs/2601.10097",
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