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1. Exploring the Galactic Warp through Asymmetries in the Kinematics of the Galactic Disk

   https://doi.org/10.3847/1538-4357/abc3c2  

   Cheng, Xinlun; Anguiano, Borja; Majewski, Steven R.; Hayes, Christian; Arras, Phil; Chiappini, Cristina; Hasselquist, Sten; de Andrade Queiroz, Anna Bárbara; Nitschelm, Christian; García-Hernández, Domingo Aníbal; et al (December 2020, The Astrophysical Journal)
2. The Structure of Multiphase Galactic Winds

   https://doi.org/10.3847/1538-4357/ac2f41  

   Fielding, Drummond B.; Bryan, Greg L. (January 2022, The Astrophysical Journal)

   Abstract We present a novel analytic framework to model the steady-state structure of multiphase galactic winds comprised of a hot, volume-filling component and a cold, clumpy component. We first derive general expressions for the structure of the hot phase for arbitrary mass, momentum, and energy source terms. Next, informed by recent simulations, we parameterize the cloud–wind mass transfer rates, which are set by the competition between turbulent mixing and radiative cooling. This enables us to cast the cloud–wind interaction as a source term for the hot phase and thereby simultaneously solve for the evolution of both phases, fully accounting for their bidirectional influence. With this model, we explore the nature of galactic winds over a broad range of conditions. We find that (i) with realistic parameter choices, we naturally produce a hot, low-density wind that transports energy while entraining a significant flux of cold clouds, (ii) mixing dominates the cold cloud acceleration and decelerates the hot wind, (iii) during mixing thermalization of relative kinetic energy provides significant heating, (iv) systems with low hot phase mass loading factors and/or star formation rates can sustain higher initial cold phase mass loading factors, but the clouds are quickly shredded, and (v) systems with large hot phase mass loading factors and/or high star formation rates cannot sustain large initial cold phase mass loading factors, but the clouds tend to grow with distance from the galaxy. Our results highlight the necessity of accounting for the multiphase structure of galactic winds, both physically and observationally, and have important implications for feedback in galactic systems. 

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3. IceCube Search for Galactic Neutrino Sources based on HAWC Observations of the Galactic Plane

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   Kheirandish, Ali; Wood, Joshua (January 2020, Pos proceedings of science)
4. On the Anisotropy of Galactic Cosmic Rays

   https://doi.org/10.3847/1538-4357/ab24c1  

   Schlickeiser, R.; Oppotsch, J.; Zhang, M.; Pogorelov, N. V. (July 2019, The Astrophysical Journal)
5. Modelling the Galactic Chemical Evolution of Helium

   https://doi.org/10.1093/mnras/staf373  

   Weller, Miqaela_K; Weinberg, David_H; Johnson, James_W (March 2025, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT We examine the galactic chemical evolution (GCE) of $^4$He in one-zone and multizone models, with particular attention to theoretical predictions of and empirical constraints on initial mass fraction (IMF)-averaged yields. Published models of massive star winds and core collapse supernovae span a factor of 2–3 in the IMF-averaged $^4$He yield, $$y\mathrm{_{He}^{CC}}$$. Published models of intermediate mass, asymptotic giant branch (AGB) stars show better agreement on the IMF-averaged yield, $$y\mathrm{_{He}^{AGB}}$$, and they predict that more than half of this yield comes from stars with $$M=4{\!-\!}8\, \mathrm{ M}_\odot$$, making AGB $^4$He enrichment rapid compared to Fe enrichment from Type Ia supernovae. Although our GCE models include many potentially complicating effects, the short enrichment time delay and mild metallicity dependence of the predicted yields makes the results quite simple: across a wide range of metallicity and age, the non-primordial $^4$He mass fraction $$\Delta Y = Y-Y_{\mathrm{P}}$$ is proportional to the abundance of promptly produced $$\alpha$$-elements such as oxygen, with $$\Delta Y/Z_{\mathrm{O}}\approx (y\mathrm{_{He}^{CC}}+y\mathrm{_{He}^{AGB}})/y\mathrm{_{O}^{CC}}$$. Reproducing solar abundances with our fiducial choice of the oxygen yield $$y\mathrm{_{O}^{CC}}=0.0071$$ implies $$y\mathrm{_{He}^{CC}}+y\mathrm{_{He}^{AGB}}\approx 0.022$$, i.e. $$0.022\,\mathrm{ M}_\odot$$ of net $^4$He production per solar mass of star formation. Our GCE models with this yield normalization are consistent with most available observations, though the implied $$y\mathrm{_{He}^{CC}}$$ is low compared to most of the published massive star yield models. More precise measurements of $$\Delta Y$$ in stars and gas across a wide range of metallicity and [$$\alpha$$/Fe] ratio could test our models more stringently, either confirming the simple picture suggested by our calculations or revealing surprises in the evolution of the second most abundant element. 

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