Galaxy formation and evolution

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.

Abstract:

<jats:p>Disentangling the (co-)evolution of individual galaxy structural components remains a difficult task, owing to the inability to cleanly isolate light from spatially overlapping components. In this pilot study of PGC,044931, observed as part of the GECKOS survey, we utilised a VIRCAM H-band image to decompose the galaxy into five photometric components, three of which dominate by contributing more than $50%$ of light in specific regions, namely, a main disc, a boxy-peanut bulge, and a nuclear disc. When mapping the photometric decompositions onto MUSE observations, we found remarkably good separation in stellar kinematic space. All three structures occupy unique locations in the parameter space of the ratio of the light-weighted stellar line-of-sight mean velocity and velocity dispersion (rm V _⋆/σ_⋆) and the high-order stellar skew (h_3). These clear and distinct kinematic behaviours allowed us to make inferences about the formation histories of the individual components from observations of the mean stellar ages and metallicities of the three components. A clear story emerged: the main disc was built over a sustained and extended star formation phase, possibly partly fuelled by gas from a low-metallicity reservoir. Early on, that disc formed a bar that buckled and subsequently formed a nuclear disc in multiple and enriched star-formation episodes. This result is an example of how careful photometric decompositions combined with spatially well-resolved stellar kinematic information can help separate age-metallicity relations of different components and therefore disentangle the formation history of a galaxy. The results of this pilot study can be extended to a differential study of all GECKOS survey galaxies to assert the true diversity of Milky Way-like galaxies.</jats:p>

Abstract:

Abstract Despite the vast amount of energy released by active galactic nuclei (AGN), their role in early galaxy formation and in regulating the growth of supermassive black holes (SMBHs) remains poorly understood. Through new high-resolution zoom-in cosmological simulations, we follow the co-evolution of 105 M⊙ black hole seeds with their host dwarf galaxy. We model ionizing feedback from a Pop III.1 progenitor, applicable to a wide range of internally or externally irradiated SMBH formation scenarios. The simulated suite progressively spans physics ranging from no AGN feedback to more complex setups including thermal, kinetic and radiative feedback – explored for both low and enhanced AGN power. Across all our models, we find that black hole seeds efficiently reach masses of ∼107 M⊙ within a ∼1010 M⊙ halo by z = 8. Although they exhibit notably different mass growth histories, these latter seem unimpeded by the presence of AGN feedback. The simulation including radiative feedback is the most distinct, with super-Eddington episodes driving fast and mass-loaded gas outflows (exceeding 2500 km s−1) up to ∼50 kpc, along with minor stellar mass suppression in the host galaxy. Our measurements are in broad agreement with moderate luminosity quasars recently observed by JWST, producing overmassive black holes (SMBH-to-galaxy mass ratios 0.01 − 1), dynamical masses of ∼109.5 M⊙, stellar masses of ∼108.5 M⊙, and high, though short-lived, Eddington fraction accretion rates. These results advocate for a scenario where AGN feedback allows for rapid SMBH growth during the reionisation era, while driving winds that extend deep into the intergalactic medium – shaping host galaxies as well as more distant surroundings.