VENUS: Two Faint Little Red Dots Separated by $\sim70\,\mathrm{pc}$ Hidden in a Single Lensed Galaxy at $z\sim7$

Hiroto Yanagisawa, Masami Ouchi, Miriam Golubchik, Masamune Oguri, Seiji Fujimoto, Vasily Kokorev, Gabriel Brammer, Fengwu Sun, Minami Nakane, Yuichi Harikane, Hiroya Umeda, Hollis B. Akins, Hakim Atek, Franz E. Bauer, Maruša Bradač, John Chisholm, Dan Coe, Jose M. Diego, Henry C. Ferguson, Steven L. Finkelstein, Lukas J. Furtak, Kohei Inayoshi, Anton M. Koekemoer, Jorryt Matthee, Rohan P. Naidu, Yoshiaki Ono, Richard Pan, Johan Richard, Luke Robbins, Chris Willott, Adi Zitrin, Ricardo O. Amorín, Larry D. Bradley, Volker Bromm, Christopher J. Conselice, Pratika Dayal, Jeyhan S. Kartaltepe, Paulo A. A. Lopes, Ray A. Lucas, Georgios E. Magdis, Nicholas S. Martis, Casey Papovich, Daniel Schaerer, Francesco Valentino, Eros Vanzella, Joseph F. V. Allingham, Norman A. Grogin, Mauro González-Otero, Massimo Ricotti, Rogier A. Windhorst

First listed 2026-01-09 | Last updated 2026-01-09

Abstract

We report the identification of a pair of faint little red dots (LRDs), dubbed Red Eyes, in a strongly-lensed galaxy at $z\sim7$ behind the PLCKG004.5-10.5 cluster, identified from the JWST Treasury program VENUS. Red Eyes are spatially resolved on the image plane with distinct colors, while the critical curve lies far north of Red Eyes, clearly requiring two different LRDs rather than a single LRD. Red Eyes is an extremely close pair of LRDs separated by $\sim70\,\mathrm{pc}$ in the source plane with a magnification of $μ\sim20$, which consistently explains another counter-image detected to the north-west. Red Eyes is hosted in a typical star-forming galaxy with $M_{\mathrm{UV,int}}\sim -19$, but its own UV emission is very faint ($M_{\mathrm{UV,int}} \gtrsim -16$). Moreover, Red Eyes does not reside at the galaxy center but lies at an offset position of approximately one effective radius $R_{\mathrm{e}}$ away from the galaxy center. If observed without lensing, Red Eyes would appear as a typical star-forming galaxy at $z\sim 7$ with $M_{\mathrm{UV}}\sim -19$, showing no apparent LRD signatures in either morphology or SED. These results suggest that multiple off-center LRDs, similar to Red Eyes, may be commonly hidden in a typical high-$z$ star-forming galaxy. In this case, various plausible scenarios may emerge, one of which is that intermediate-mass black holes (IMBHs) with $M_\mathrm{BH}\sim10^{4\text{--}6}\,M_\odot$ may form in star clusters on a stellar disk and contribute to the growth of the central supermassive black hole via mergers, with some IMBHs detectable as luminous LRDs in a sufficiently active and massive phase.

Short digest

JWST VENUS imaging of PLCK G004.5−10.5 uncovers Red Eyes, a spatially resolved pair of little red dots embedded in a single z∼7 lensed galaxy; the lens geometry and a NW counter-image require two distinct sources. The components are separated by ∼70 pc in the source plane and magnified by μ∼20, lying ~1 Re off the host center; the host is a typical SFG with M_UV,int≈−19 while each LRD is UV-faint (M_UV,int≳−16). SED fits to the multiple images demand an added LRD (blackbody-like) component, whereas dusty SFG-only models underpredict the UV. Because these LRDs would be invisible without lensing, the work suggests hidden, off-center LRDs may be common in typical z∼7 galaxies, consistent with IMBH (10^4–10^6 M⊙) seeds forming in disk star clusters and later merging toward SMBH growth.

Key figures to inspect

• Figure 1: Inspect the lens map and image-plane geometry—note Red Eyes’ positions relative to the critical curves and the NW counter-image, which argues for two discrete LRDs and sets up the source-plane reconstruction yielding the ~70 pc separation.
• Figure 2: Check how LRD-SW1, LRD-SW2, and LRD-NW pass the color/slope thresholds while nearby SFG components fail; the cyan intrinsic points show that, unlensed, the system would not be flagged as an LRD.
• Figure 3: In the SW cutouts and SEDs, compare fits with and without the added blackbody component; dusty SFG-only models underpredict the UV, and the redshift posterior confirms the z∼7 solution for the LRD components.
• Figure 4: Repeat the SED scrutiny for the NW image to see consistency across counter-images, supporting the magnification (μ∼20) and the LRD interpretation for both components.