First author: Josh Borrow
Early galaxies were the radiation source for reionization, with the photoheating feedback from the reionization process expected to reduce the efficiency of star formation in low mass haloes. Hence, to fully understand reionization and galaxy formation, we must study their impact on each other. The THESAN project has so far aimed to study the impact of galaxy formation physics on reionization, but here we present the new THESAN simulations with a factor 50 higher resolution ($m_{\rm b} \approx 10^4$~M$\odot$) that aim to self-consistently study the back-reaction of reionization on galaxies.
First author: Jade Powell
We perform three-dimensional simulations of magnetorotational supernovae using a $39,M_{\odot}$ progenitor star with two different initial magnetic field strengths of $10^{10}$ G and $10^{12}$ G in the core. Both models rapidly undergo shock revival and their explosion energies asymptote within a few hundred milliseconds to values of $\gtrsim 2\times10^{51}$ erg after conservatively correcting for the binding energy of the envelope. Magnetically collimated, non-relativistic jets form in both models, though the jets are subject to non-axisymmetric instabilities.
Marko Mićić
Dual AGN are important for understanding galaxy-merger-triggered fueling of black holes and hierarchical growth of structures. The least explored type of dual AGN are those associated with mergers of two dwarf galaxies. According to observations and cosmological simulations, dwarf galaxies are the most abundant type of galaxies in the early Universe and the galaxy merger rate is dominated by dwarfs. However, these mergers are generally too distant to be directly observed, and low-redshift dwarf-dwarf merger-related dual AGN are notoriously hard to find.
First author: Koshy George
Spiral galaxies undergo strong ram-pressure effects when they fall into the galaxy cluster potential. As a consequence, their gas is stripped to form extended tails within which star formation can happen, giving them the typical jellyfish appearance. The ultraviolet imaging observations of jellyfish galaxies provide an opportunity to understand ongoing star formation in the stripped tails. We report the ultraviolet observations of the jellyfish galaxies JW39, JO60, JO194 and compare with observations in optical continuum and $\mathrm{H}{\alpha}$.
P Adsley
Globular clusters contain multiple stellar populations, with some previous generation of stars polluting the current stars with heavier elements. Understanding the history of globular clusters is helpful in understanding how galaxies merged and evolved and therefore constraining the site or sites of this historic pollution is a priority. The acceptable temperature and density conditions of these polluting sites depend on critical <span class="search-hit mathjax">reaction</span> rates. In this paper, three experimental studies helping to constrain astrophysically important <span class="search-hit mathjax">reaction</span> rates are briefly discussed.
Xingzhuo Chen
We use physics informed neural networks (PINNs) to solve the radiative transfer equation and calculate a synthetic spectrum for a Type Ia supernova (SN~Ia) SN 2011fe. The calculation is based on local thermodynamic equilibrium (LTE) and 9 elements are included. Physical processes included are approximate radiative equilibrium, bound-bound transitions, and the Doppler effect. A PINN based gamma-ray scattering approximation is used for radioactive decay energy deposition. The PINN synthetic spectrum is compared to an observed spectrum, a synthetic spectrum calculated by the Monte-Carlo radiative transfer program TARDIS, and the formal solution of the radiative transfer equation.
First author: Nanoom Lee
We develop a novel general formalism allowing us to obtain values of the Hubble constant in agreement with late-time observables without degrading the fit to Cosmic Microwave Background data, considering perturbative modifications around a fiducial $\Lambda$CDM cosmology. Taking as proof-of-principle the case of a time-varying electron mass and fine structure constant, we demonstrate that a modified recombination can solve the Hubble tension and lower $S_8$ to match weak lensing measurements.
