Galaxy formation and evolution

Abstract:

Abstract Understanding black hole–galaxy co-evolution and the role of AGN feedback requires complete AGN samples, including heavily obscured systems. Such sources are key to constraining the black hole accretion rate density over cosmic time, yet they are challenging to identify and characterise across most wavelengths. In this work, we present the first UV line–selected ([Ne v]3426 and C iv1549) sample of obscured AGN with full X-ray-to-radio coverage, assembled by combining data from the Chandra COSMOS Legacy survey, the COSMOS2020 UV–NIR catalogue, mid- and far-IR photometry from XID+, and radio observations from the VLA and MIGHTEE surveys. Using CIGALE to perform spectral energy distribution (SED) fitting, we analyse 184 obscured AGN at 0.6 < z < 1.2 and 1.5 < z < 3.1, enabling detailed measurements of AGN and host galaxy properties, and direct comparison with Simba hydrodynamical simulations. We find that X-ray and radio data are essential for accurate SED fits, with the radio band proving critical when X-ray detections are missing or in cases of poor IR coverage. Comparisons with matched non-active galaxies and simulations suggest that the [Ne v]-selected sources are in a pre-quenching stage, while the C iv-selected ones are likely quenched by AGN activity. Our results indicate that [Ne v] and C iv selections target galaxies in a transient phase of their co-evolution, characterised by intense, obscured accretion, and pave the way for future extensions with upcoming large area high-z spectroscopic surveys.

Abstract:

ABSTRACT Understanding the cold atomic hydrogen gas (H i) within cosmic filaments has the potential to pin down the relationship between the low density gas in the cosmic web and how the galaxies that lie within it grow using this material. We report the discovery of a cosmic filament using 14 H i-selected galaxies that form a very thin elongated structure of 1.7 Mpc. These galaxies are embedded within a much larger cosmic web filament, traced by optical galaxies, that spans at least $\sim 15$ Mpc. We find that the spin axes of the H i galaxies are significantly more strongly aligned with the cosmic web filament ($\langle \vert \cos \psi \vert \rangle = 0.64 \pm 0.05$) than cosmological simulations predict, with the optically selected galaxies showing alignment to a lesser degree ($\langle \vert \cos \psi \vert \rangle = 0.55 \pm 0.05$). This structure demonstrates that within the cosmic filament, the angular momentum of galaxies is closely connected to the large-scale filamentary structure. We also find strong evidence that the galaxies are orbiting around the spine of the filament, making this one of the largest rotating structures discovered thus far, and from which we can infer that there is transfer of angular momentum from the filament to the individual galaxies. The abundance of H i galaxies along the filament and the low dynamical temperature of the galaxies within the filament indicates that this filament is at an early evolutionary stage where the imprint of cosmic matter flow on galaxies has been preserved over cosmic time.

Abstract:

This study offers a comprehensive bibliometric and text‐mining overview of two decades of sustainability‐oriented entrepreneurship research. Drawing on 7563 peer‐reviewed articles from the Web of Science Core Collection, we map the field's evolution, thematic structure, and disciplinary convergence, identifying influential authors, networks, and journals. Using rule‐based classification and unsupervised learning, we categorize contributions within a four‐pillar framework encompassing environmental, social, economic, and cultural dimensions and examine their prevalence, overlap, and temporal trends. The results reveal a pronounced shift toward transdisciplinarity: 77% of articles engage with at least three pillars, and 34.5% address all four simultaneously. Building directly on this empirical evidence, we propose the Four‐Pillar Intersectionality Framework (F‐PIF), which reconceptualizes sustainable entrepreneurship as a transdisciplinary knowledge domain shaped by interdependent sustainability logics. The F‐PIF is therefore both derived from and supported by the bibliometric findings, providing an empirically grounded conceptual model that advances theoretical understanding and offers practical guidance for scholars and practitioners navigating entrepreneurship in the age of sustainability.

Abstract:

We present a comprehensive analysis of the MIRI Extremely Red Object Virgil, a Lyα emitter at zspec = 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 Hα, 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 μm 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.