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Rapidly outflowing cold H  i gas is ubiquitously observed to be cospatial with a hot phase in galactic winds, yet the ablation time of cold gas by the hot phase should be much shorter than the acceleration time. Previous work showed efficient radiative cooling enables clouds to survive in hot galactic winds under certain conditions, as can magnetic fields even in purely adiabatic simulations for sufficiently small density contrasts between the wind and cloud. In this work, we study the interplay between radiative cooling and magnetic draping via three dimensional radiative magnetohydrodynamic simulations with perpendicular ambient fields and tangled internal cloud fields. We find magnetic fields decrease the critical cloud radius for survival by two orders of magnitude (i.e. to sub-pc scales) in the strongly magnetized (βwind = 1) case. Our results show magnetic fields (i) accelerate cloud entrainment through magnetic draping, (ii) can cause faster cloud destruction in cases of inefficient radiative cooling, (iii) do not significantly suppress mass growth for efficiently cooling clouds, and, crucially, in combination with radiative cooling (iv) reduce the average overdensity by providing non-thermal pressure support of the cold gas. This substantially reduces the acceleration time compared to the destruction time (more than due to draping alone), enhancing cloud survival. Our results may help to explain the cold tiny rapidly outflowing cold gas observed in galactic winds and the subsequent high covering fraction of cold material in galactic haloes. [ABSTRACT FROM AUTHOR]

Recent JWST observations of the z  = 10.6 galaxy GN-z11 have revealed a very high gas-phase nitrogen abundance (higher than four times the solar value), a very small half-light radius (≈60 pc), and a large stellar mass (M s ≈ 109 M⊙) for its size. We consider that this object is a forming galactic nucleus or ultra-compact dwarf galaxy rather than a proto globular cluster, and thereby investigate the chemical abundance pattern using one-zone chemical evolution models. The principal results of the models are as follows. The observed log (N/O) > −0.24, log (C/O) > −0.78, and 12 + log (O/H) ≈ 7.8 can be self-consistently reproduced by the models both with very short star formation time-scales (<107 yr) and with top-heavy stellar initial mass functions. The adopted assumption of no chemical enrichment by massive (m > 25 M⊙) core collapse supernovae (CCSNe) is also important for the reproduction of high gas-phase log (N/O), because such CCSNe can decrease high log (N/O) of gas polluted by OB and Wolf–Rayet stars. GN-z11 can have a significant fraction (>0.5) of nitrogen-rich ([N/Fe] > 0.5) stars, which implies a possible link between nitrogen-rich stellar populations of the inner Galaxy and giant elliptical galaxies and high- z objects with high gas-phase log (N/O) like GN-z11. [ABSTRACT FROM AUTHOR]

A multiwavelength study of galaxies is important to understand their formation and evolution. Only in the recent past, thanks to the Atacama Large (Sub) Millimeter Array (ALMA), were we able to study the far-infrared (IR) properties of galaxies at high redshifts. In this article, we summarize recent research highlights and their significance to our understanding of early galaxy evolution from the ALPINE survey, a large program with ALMA to observe the dust continuum and 158 μ m C + emission of normal star-forming galaxies at z = 4–6. Combined with ancillary data at UV through near-IR wavelengths, ALPINE provides the currently largest multiwavelength sample of post-reionization galaxies and has advanced our understanding of (i) the demographics of C + emission; (ii) the relation of star formation and C + emission; (iii) the gas content; (iv) outflows and enrichment of the intergalactic medium; and (v) the kinematics, emergence of disks, and merger rates in galaxies at z > 4 . ALPINE builds the basis for more detailed measurements with the next generation of telescopes, and places itself as an important post-reionization baseline sample to allow a continuous study of galaxies over 13 billion years of cosmic time. [ABSTRACT FROM AUTHOR]