_version_ 1866908302459273216
author Rinaldi, Pierluigi
Pérez-González, Pablo G.
Rieke, George H.
Lyu, Jianwei
D'Eugenio, Francesco
Wu, Zihao
Carniani, Stefano
Looser, Tobias J.
Shivaei, Irene
Boogaard, Leindert A.
Diaz-Santos, Tanio
Colina, Luis
Östlin, Göran
Alberts, Stacey
Álvarez-Márquez, Javier
Annuziatella, Marianna
Aravena, Manuel
Bhatawdekar, Rachana
Bunker, Andrew J.
Caputi, Karina I.
Charlot, Stéphane
Gómez, Alejandro Crespo
Curti, Mirko
Eckart, Andreas
Gillman, Steven
Hainline, Kevin
Kumari, Nimisha
Hjorth, Jens
Iani, Edoardo
Inami, Hanae
Ji, Zhiyuan
Johnson, Benjamin D.
Jones, Gareth C.
Labiano, Álvaro
Maiolino, Roberto
Melinder, Jens
Moutard, Thibaud
Peißker, Florian
Rieke, Marcia
Robertson, Brant
Scholtz, Jan
Tacchella, Sandro
van der Werf, Paul P.
Walter, Fabian
Williams, Christina C.
Willott, Chris
Witstok, Joris
Übler, Hannah
Zhu, Yongda
author_facet Rinaldi, Pierluigi
Pérez-González, Pablo G.
Rieke, George H.
Lyu, Jianwei
D'Eugenio, Francesco
Wu, Zihao
Carniani, Stefano
Looser, Tobias J.
Shivaei, Irene
Boogaard, Leindert A.
Diaz-Santos, Tanio
Colina, Luis
Östlin, Göran
Alberts, Stacey
Álvarez-Márquez, Javier
Annuziatella, Marianna
Aravena, Manuel
Bhatawdekar, Rachana
Bunker, Andrew J.
Caputi, Karina I.
Charlot, Stéphane
Gómez, Alejandro Crespo
Curti, Mirko
Eckart, Andreas
Gillman, Steven
Hainline, Kevin
Kumari, Nimisha
Hjorth, Jens
Iani, Edoardo
Inami, Hanae
Ji, Zhiyuan
Johnson, Benjamin D.
Jones, Gareth C.
Labiano, Álvaro
Maiolino, Roberto
Melinder, Jens
Moutard, Thibaud
Peißker, Florian
Rieke, Marcia
Robertson, Brant
Scholtz, Jan
Tacchella, Sandro
van der Werf, Paul P.
Walter, Fabian
Williams, Christina C.
Willott, Chris
Witstok, Joris
Übler, Hannah
Zhu, Yongda
contents We present a comprehensive analysis of the MIRI Extremely Red Object Virgil, a Lyman-$α$ emitter at $z_{spec} = 6.6379 \pm 0.0035$ 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 = $2.84\pm0.04$ 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 multi-wavelength approach incorporating MIRI to uncover such extreme sources at $z\gtrsim6$ and to shed light on the interplay between galaxy evolution and early black hole growth during Cosmic Reionization.
format Preprint
id arxiv_https___arxiv_org_abs_2504_01852
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Deciphering the Nature of Virgil: An Obscured AGN Lurking Within an Apparently Normal Lyman-α Emitter During Cosmic Reionization
Rinaldi, Pierluigi
Pérez-González, Pablo G.
Rieke, George H.
Lyu, Jianwei
D'Eugenio, Francesco
Wu, Zihao
Carniani, Stefano
Looser, Tobias J.
Shivaei, Irene
Boogaard, Leindert A.
Diaz-Santos, Tanio
Colina, Luis
Östlin, Göran
Alberts, Stacey
Álvarez-Márquez, Javier
Annuziatella, Marianna
Aravena, Manuel
Bhatawdekar, Rachana
Bunker, Andrew J.
Caputi, Karina I.
Charlot, Stéphane
Gómez, Alejandro Crespo
Curti, Mirko
Eckart, Andreas
Gillman, Steven
Hainline, Kevin
Kumari, Nimisha
Hjorth, Jens
Iani, Edoardo
Inami, Hanae
Ji, Zhiyuan
Johnson, Benjamin D.
Jones, Gareth C.
Labiano, Álvaro
Maiolino, Roberto
Melinder, Jens
Moutard, Thibaud
Peißker, Florian
Rieke, Marcia
Robertson, Brant
Scholtz, Jan
Tacchella, Sandro
van der Werf, Paul P.
Walter, Fabian
Williams, Christina C.
Willott, Chris
Witstok, Joris
Übler, Hannah
Zhu, Yongda
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
We present a comprehensive analysis of the MIRI Extremely Red Object Virgil, a Lyman-$α$ emitter at $z_{spec} = 6.6379 \pm 0.0035$ 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 = $2.84\pm0.04$ 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 multi-wavelength approach incorporating MIRI to uncover such extreme sources at $z\gtrsim6$ and to shed light on the interplay between galaxy evolution and early black hole growth during Cosmic Reionization.
title Deciphering the Nature of Virgil: An Obscured AGN Lurking Within an Apparently Normal Lyman-α Emitter During Cosmic Reionization
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2504.01852