Cosmic-Ray-driven Outflows from the Large Magellanic Cloud: Contributions to the LMC Filament

Bustard, Chad; Zweibel, Ellen G.; Gallagher, John S.; Farber, Ryan

doi:10.3847/1538-4357/ab7fa3

Cited by 45 publications

(45 citation statements)

References 100 publications

(152 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…CR-driven winds are generally denser, colder, and smoother than the thermal supernova-driven outflows (Fig. 2c; e.g., Pakmor et al 2016;Ruszkowski et al 2017;Pfrommer et al 2017;Girichidis et al 2018;Bustard et al 2019;Vijayan et al 2020).…”

Section: Cosmic Raysmentioning

confidence: 94%

Cool outflows in galaxies and their implications

Veilleux

Maiolino

Bolatto

et al. 2020

Astron Astrophys Rev

419

310

View full text Add to dashboard Cite

Neutral-atomic and molecular outflows are a common occurrence in galaxies, near and far. They operate over the full extent of their galaxy hosts, from the innermost regions of galactic nuclei to the outermost reaches of galaxy halos. They carry a substantial amount of material that would otherwise have been used to form new stars. These cool outflows may have a profound impact on the evolution of their host galaxies and environments. This article provides an overview of the basic physics of cool outflows, a comprehensive assessment of the observational techniques and diagnostic tools used to characterize them, a detailed description of the best-studied cases, and a more general discussion of the statistical properties of these outflows in the local and distant universe. The remaining outstanding issues that have not yet been resolved are summarized at the end of the review to inspire new research directions.

show abstract

Section: Cosmic Raysmentioning

confidence: 94%

Cool outflows in galaxies and their implications

Veilleux

Maiolino

Bolatto

et al. 2020

Astron Astrophys Rev

419

310

View full text Add to dashboard Cite

show abstract

“…Cosmic rays are likely an important source of energy in the CGM. In the Milky Way ISM, cosmic-ray energy is roughly in equipartition with thermal and magnetic energies (Ginzburg & Ptuskin 1985;Boulares & Cox 1990), and many recent simulations have shown that cosmic rays launch far-reaching galactic outflows (Uhlig et al 2012;Booth et al 2013;Girichidis et al 2016;Simpson et al 2016;Ruszkowski et al 2017;Bustard et al 2020;Jana et al 2020), altering the phase structure of the CGM (Salem et al 2016;Butsky & Quinn 2018;Buck et al 2020;Ji et al 2020). Galaxy-scale simulations that include cosmic rays find that cosmic-ray pressure may even be the dominant source of pressure in the CGM (Girichidis et al 2018;Ji et al 2020).…”

Section: Introductionmentioning

confidence: 99%

The Impact of Cosmic Rays on Thermal Instability in the Circumgalactic Medium

Butsky

Fielding

Hayward

et al. 2020

ApJ

View full text Add to dashboard Cite

Large reservoirs of cold (∼10 4 K) gas exist out to and beyond the virial radius in the circumgalactic medium (CGM) of all types of galaxies. Photoionization modeling suggests that cold CGM gas has significantly lower densities than expected by theoretical predictions based on thermal pressure equilibrium with hot CGM gas. In this work, we investigate the impact of cosmic-ray physics on the formation of cold gas via thermal instability. We use idealized three-dimensional magnetohydrodynamic simulations to follow the evolution of thermally unstable gas in a gravitationally stratified medium. We find that cosmic-ray pressure lowers the density and increases the size of cold gas clouds formed through thermal instability. We develop a simple model for how the cold cloud sizes and the relative densities of cold and hot gas depend on cosmic-ray pressure. Cosmic-ray pressure can help counteract gravity to keep cold gas in the CGM for longer, thereby increasing the predicted cold mass fraction and decreasing the predicted cold gas inflow rates. Efficient cosmic-ray transport, by streaming or diffusion, redistributes cosmicray pressure from the cold gas to the background medium, resulting in cold gas properties that are in between those predicted by simulations with inefficient transport and simulations without cosmic rays. We show that cosmic rays can significantly reduce galactic accretion rates and resolve the tension between theoretical models and observational constraints on the properties of cold CGM gas.

show abstract

“…To our knowledge, all currently published simulations of LMC-SMC interactions lack sufficient resolution to capture cloud survival and converged mass growth. This is also true of isolated LMC ram pressure stripping simulations (Salem et al 2015;Bustard et al 2018Bustard et al , 2020. We will discuss the implications of this further in §6.2.…”

Section: Radiative Turbulent Mixingmentioning

confidence: 77%

Radiative Turbulent Mixing Layers and the Survival of Magellanic Debris

Bustard,

Gronke

2021

Preprint

Self Cite

View full text Add to dashboard Cite

The Magellanic Stream is sculpted by its infall through the Milky Way's circumgalactic medium, but the rates and directions of mass, momentum, and energy exchange through the Stream-halo interface are relative unknowns critical for determining the origin and fate of the Stream. Complementary to large-scale simulations of LMC-SMC interactions, we apply new insights derived from idealized, highresolution "cloud-crushing" and radiative turbulent mixing layer simulations to the Leading Arm and Trailing Stream. Contrary to classical expectations of fast cloud breakup, we predict that the Leading Arm and much of the Trailing Stream should be surviving infall and even gaining mass due to strong radiative cooling. Provided a sufficiently supersonic tidal swing-out from the Clouds, the present-day Leading Arm could be a series of high-density clumps in the cooling tail behind the progenitor cloud. We back up our analytic framework with a suite of converged wind-tunnel simulations, finding that previous results on cloud survival and mass growth can be extended to high Mach number (M) flows with a modified drag time t drag ∝ 1 + M and longer growth time. We also simulate the Trailing Stream; we find that the growth time is long (∼ Gyrs) compared to the infall time, and approximate Hα emission is low on average (∼few mR) but can be up to tens of mR in bright spots. Our findings also have broader extragalactic implications for e.g. galactic winds, which we discuss.

show abstract

Cosmic-Ray-driven Outflows from the Large Magellanic Cloud: Contributions to the LMC Filament

Cited by 45 publications

References 100 publications

Cool outflows in galaxies and their implications

Cool outflows in galaxies and their implications

The Impact of Cosmic Rays on Thermal Instability in the Circumgalactic Medium

Radiative Turbulent Mixing Layers and the Survival of Magellanic Debris

Contact Info

Product

Resources

About