SN 2022riv in RX J2129: Discovery, Spectroscopic Classification, and Microlensing of a Strongly Lensed Type Ia Supernova from JWST and HST Observations

Dhanasingham, B, Kelly, PL, Chen, W, Pierel, J, Oguri, M, Perera, D, Diego, JM, Zitrin, A, Meena, AK, Jauzac, M, Mahler, G, Mamuzic, E, Williams, LLR, Taak, YC, Koekemoer, AM, Broadhurst, TJ, Furtak, LJ, Lagattuta, D, Williams, H, Dalrymple, K et al (2026) SN 2022riv in RX J2129: Discovery, Spectroscopic Classification, and Microlensing of a Strongly Lensed Type Ia Supernova from JWST and HST Observations. The Astrophysical Journal, 1008 (2). ISSN 0004-637X

Preview

Text SN 2022riv in RX J2129_ Discovery, Spectroscopic Classification, and Microlensing of a Strongly Lensed Type Ia Supernova from JWST and HST Observations.pdf - Published Version Available under License Creative Commons Attribution. Download (12MB) | Preview

Abstract

The multiply imaged SN 2022riv was discovered through a search of galaxy cluster fields as part of a Hubble Space Telescope (HST) SNAP program to find highly magnified stars. The supernova (SN) was detected in the image corresponding to the longest time delay of a galaxy at redshift z = 1.522, strongly lensed by the foreground galaxy cluster RX J2129.7+0005. Follow up James Webb Space Telescope (JWST) NIRSpec G140M and PRISM spectroscopy yields an SN Ia classification. Using the SALT3-NIR light-curve fitter, we obtain a cosmology-independent measurement of the magnification of 5.35  ±  1.01 for the last-to-arrive image of the SN, with multiple SALT SN spectral time-series models yielding consistent constraints. The last-to-arrive image of SN 2022riv we detect appeared adjacent to the brightest cluster galaxy (BCG) at a location with an exceptionally high stellar mass density (∼1–2 dex higher than that of SN Refsdal), where microlensing is expected to introduce a 20%–50% modulation of the magnification. Analyzing six independent lens models of the cluster, we find that four predict the magnification with much greater precision (p  <  0.05) than would be expected by random chance, given the large effect anticipated from microlensing. Five models yield magnifications of roughly 4–7 (within 1σ) prior to accounting for microlensing, whereas HoliGRALE favors a significantly higher value of 15.39  ±  0.85. After incorporating nominal microlensing, the HoliGRALE prediction is within 1σ tension with our measurement. A companion paper will present constraints on the relative time delay of the image that arrived earlier.

Item Type:	Article
Uncontrolled Keywords:	5101 Astronomical Sciences; 51 Physical Sciences; 0201 Astronomical and Space Sciences; 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics; 0306 Physical Chemistry (incl. Structural); Astronomy & Astrophysics; 5101 Astronomical sciences; 5107 Particle and high energy physics; 5109 Space sciences
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Divisions:	Astrophysics Research Institute
Publisher:	IOP Publishing
Date of acceptance:	4 August 2026
Date of first compliant Open Access:	5 October 2026
Date Deposited:	05 Oct 2026 13:51
Last Modified:	05 Oct 2026 13:51
DOI or ID number:	10.3847/1538-4357/ae9606
URI:	https://researchonline.ljmu.ac.uk/id/eprint/29606

View Item