Co-evolution of the interstellar dust and chemistry in low-metallicity dwarf galaxies

The cycle of gas in and around galaxies plays a fundamental role in galaxy formation. Recent hydrodynamical simulations have managed to reach (sub-)parsec-scale resolutions to follow the small-scale physics in the interstellar medium (ISM). As our knowledge of the gas cycle comes from multi-wavelength observations, detailed modeling of the ISM chemistry is of fundamental importance. However, interstellar dust, the major catalyst of ISM chemistry, is often regarded as a non-evolving species. In this talk, I will present our recent progress on resolved hydrodynamical simulations of low-metallicity dwarf galaxies coupled with chemistry and dust evolution. Our resolution (1 M_sun per gas particle, spatial resolution ~0.2 pc) allows us to resolve not only the individual supernova blastwaves but also the detailed structure of the star-forming clouds. I will demonstrate how dust evolution helps explain the observed CO luminosity and why the observationally derived dust-to-gas ratio might have been underestimated at low metallicity. Finally, I will also discuss dust-enriched galactic outflows as a possible origin of the intergalactic dust.

Rotating plasma disks orbiting a central object, like a black hole, are ubiquitous in the universe. However, questions regarding their dynamical evolution, such as the mechanisms of angular momentum transport and the role of magnetic fields in seeding instabilities, turbulence and launching jets, remain outstanding.

In this talk I will give an overview of a new generation of laboratory experiments fielded in high-energy-density facilities (such as the MAGPIE pulsed-power generator at Imperial College London and the OMEGA laser at the University of Rochester), designed to probe plasma physics relevant to accretion disks and jet launching regions.

In these experiments, a differentially rotating plasma column is driven and sustained by the collision of multiple inflowing plasma jets. The free-boundary design allows the plasma to expand axially, forming supersonic rotating jets which remain collimated as they propagate through the vacuum chamber. The rotating plasma flow is high magnetic Reynolds number (ranging from 10 to 103) and has a quasi-Keplerian stratification. I will discuss the potential of  these experiments to study the magneto-rotational instability, the Omega-effect, and the overall effect of magnetic fields in high-Rm rotating plasmas on laboratory scales.

Cosmology from Cosmic Shear Power Spectra with Hyper Suprime-Cam Year 3 Data

Gravity, turbulence, magnetic fields, and stellar feedback all play important roles in star formation and in setting the star formation rate (SFR). The impact of these physical processes is reflected in the distribution and dynamics of the gas of these star forming regions. In this talk, I present our work using a suite of 3D magnetohydrodynamical (MHD) simulations to study  the shape and evolution of the density distribution and how the compression and expansion rates of the gas are linked to the gas density distribution. We find that supersonic turbulence produces an approximate equilibrium between compressing and expanding gas near the mean density and that protostellar jets produce rapidly expanding and compressing gas at low densities.  We also find that the net gas mass flux becomes constant at a density above the transition density (the transition between the lognormal and power-law portions of the PDF) but below the sink formation threshold.  At this density, the net gas mass flux matches the mean SFR, suggesting that the gas dynamics at this density sets the overall star formation rate of the simulation.