Pierluigi Rinaldi, Pablo G. Pérez‐González, G. H. Rieke, Jianwei Lyu, Francesco D’Eugenio, Zihao Wu, Stefano Carniani, Tobias J. Looser, Irene Shivaei, Leindert Boogaard, T. Díaz-Santos, L. Colina, Göran Östlin, Stacey Alberts, Javier Álvarez-Márquez, Marianna Annunziatella, Manuel Aravena, Rachana Bhatawdekar, Andrew J. Bunker, K. I. Caputi, S. Charlot, Alejandro Crespo Gómez, Mirko Curti, A. Eckart, Steven Gillman, Kevin Hainline, Nimisha Kumari, J. Hjorth, Edoardo Iani, Hanae Inami, Zhiyuan Ji, Benjamin D. Johnson, Gareth C. Jones, Á. Labiano, R. Maiolino, Jens Melinder, T. Moutard, Florian Peißker, Marcia Rieke, Brant Robertson, Jan Scholtz, Sandro Tacchella, P. van der Werf, Fabian Walter, Christina C. Williams, Chris J. Willott, Joris Witstok, Hannah Übler, Yongda Zhu
Abstract We present a comprehensive analysis of the MIRI Extremely Red Object Virgil, a Ly α emitter at z spec = 6.6379 ± 0.0035 with the photometric properties of a Little Red Dot. Leveraging new JWST/MIRI imaging from the MIDIS and PAHSPECS programs, we confirm Virgil’s extraordinary nature among galaxies in JADES/GOODS-South, exhibiting a strikingly red NIRCam-to-MIRI color (F444W–F1500W = 2.84 ± 0.04 mag). Deep NIRSpec/PRISM spectroscopy from the OASIS program offers key insights into the host galaxy, revealing properties of an average star-forming galaxy during Cosmic Reionization, such as a subsolar metallicity, low-to-moderate dust content, and a relatively high ionization parameter and electron temperature. By estimating the star formation rate of Virgil from UV and H α , we find evidence that the galaxy is either entering or fading out of a bursty episode. Although line-ratio diagnostics employed at high z would classify Virgil as an active galactic nucleus (AGN), this classification becomes ambiguous once redshift evolution is considered. Nonetheless, Virgil occupies the same parameter space as recently confirmed AGNs at similar redshifts. The new deep MIRI data at 15 μ m reinforce the AGN nature of Virgil, as inferred from multiple spectral energy distribution (SED) fitting codes. Virgil’s rising infrared SED and UV excess resemble those of Dust-Obscured Galaxies (DOGs) studied with Spitzer at Cosmic Noon, particularly blue-excess HotDOGs. Our results highlight the need for a multiwavelength approach incorporating MIRI to uncover such extreme sources at z ≳ 6 and to shed light on the interplay between galaxy evolution and early black hole growth during Cosmic Reionization.