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1. Cosmic Crashes

   Evans, Aaron S.; Armus, Lee (December 2021, Scientific American)

   Moskowitz, Clara (Ed.)

   Galaxy Collisions Preview Milky Way’s Fate New revelations about how galaxies collide show what might happen when our galaxy meets Andromeda 

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2. CHAMP cosmic rays

   https://doi.org/10.1088/1475-7516/2019/07/015  

   Dunsky, David; Hall, Lawrence J.; Harigaya, Keisuke (July 2019, Journal of Cosmology and Astroparticle Physics)
3. Cosmic axion background

   https://doi.org/10.1103/PhysRevD.103.115004  

   Dror, Jeff A.; Murayama, Hitoshi; Rodd, Nicholas L. (June 2021, Physical Review D)
4. The cosmic-ray staircase: the outcome of the cosmic-ray acoustic instability

   https://doi.org/10.1093/mnras/stac1123  

   Tsung, Tsun Hin Navin; Oh, S. Peng; Jiang, Yan-Fei (April 2022, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT Recently, cosmic rays (CRs) have emerged as a leading candidate for driving galactic winds. Small-scale processes can dramatically affect global wind properties. We run two-moment simulations of CR streaming to study how sound waves are driven unstable by phase-shifted CR forces and CR heating. We verify linear theory growth rates. As the sound waves grow non-linear, they steepen into a quasi-periodic series of propagating shocks; the density jumps at shocks create CR bottlenecks. The depth of a propagating bottleneck depends on both the density jump and its velocity; ΔPc is smaller for rapidly moving bottlenecks. A series of bottlenecks creates a CR staircase structure, which can be understood from a convex hull construction. The system reaches a steady state between growth of new perturbations, and stair mergers. CRs are decoupled at plateaus, but exert intense forces and heating at stair jumps. The absence of CR heating at plateaus leads to cooling, strong gas pressure gradients and further shocks. If bottlenecks are stationary, they can drastically modify global flows; if their propagation times are comparable to dynamical times, their effects on global momentum and energy transfer are modest. The CR acoustic instability is likely relevant in thermal interfaces between cold and hot gas, as well as galactic winds. Similar to increased opacity in radiative flows, the build-up of CR pressure due to bottlenecks can significantly increase mass outflow rates, by up to an order of magnitude. It seeds unusual forms of thermal instability, and the shocks could have distinct observational signatures, on ∼kpc scales. 

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5. Cosmic Explorer MPSAC Dataset

   https://doi.org/10.5281/zenodo.8087733  

   Gupta, Ish (January 2023, Zenodo)

   This dataset contains the compact binary populations that were used in the Cosmic Explorer MPSAC White paper¹ (submitted to the NSF MPSAC ngGW Subcommittee) and the accompanying technical paper². Contents: 1. 1-year populations for binary black hole (BBH), binary neutron star (BNS), neutron star-black hole (NSBH), intermediate mass binary black hole (IMBBH), Population III (Pop 3) binary black holes and primordial black hole (PBH) mergers. It also contains the SNRs and measurement errors on intrinsic and extrinsic parameters calculated using gwbench³. 2. 1/4-year sub-population of BNS mergers for which errors on tidal parameters were calculated. 3. An ipython notebook (instructions.ipynb) that shows how the data can be used. References: 1. Evans, Matthew et al. Cosmic Explorer: A Submission to the NSF MPSAC ngGW Subcommittee (2023). arXiv: 2306.13745 [gr-qc]. 2. Gupta, Ish et al. Characterizing Gravitational Wave Detector Networks: From A^# to Cosmic Explorer (2023). In preparation. 3. Borhanian, Ssohrab. GWBENCH: a novel Fisher information package for gravitational-wave benchmarking. Class. Quant. Grav. 38, 175014 (2021). arXiv: 2010.15202 [gr-qc]. 

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