A5101871517- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Scientific Research and Discoveries
- Astronomical Observations and Instrumentation
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Cosmology and Gravitation Theories
- History and Developments in Astronomy
University of Surrey
2022-2025
Abstract Nuclear Star Clusters (NSCs) are amongst the densest stellar systems in Universe and found at centres of many spiral elliptical galaxies, up to ∼ 40 % dwarf galaxies. However, their formation mechanisms, possible links globular clusters (GCs), remain debated. This paper uses cosmological simulations galaxies a spatial resolution ∼3 pc present new mechanism for NSCs, showing they naturally emerge subset dwarfs with present-day halo masses ${\sim }\, 5\times 10^{9}\, \rm {M}_{\odot...
Nuclear Star Clusters (NSCs) are amongst the densest stellar systems in Universe and found at centres of many bright spiral elliptical galaxies, up to ${\sim}$40% dwarf galaxies. However, their formation mechanisms, possible links globular clusters (GCs), remain debated. This paper uses EDGE simulations - a collection zoom-in, cosmological isolated galaxies -- present new mechanism for NSCs. We find that, gas spatial mass resolution ${\sim}3\,$pc ${\sim}161$ M$_\odot$, respectively, NSCs...
The stellar-mass--halo-mass (SMHM) relation is central to our understanding of galaxy formation and the nature dark matter. However, its normalisation, slope, scatter are highly uncertain at dwarf scales. In this paper, we present DarkLight, a new semi-empirical model designed robustly predict SMHM for smallest galaxies. DarkLight harnesses correlation between mean star rate dwarfs their peak rotation speed -- $\langle$SFR$\rangle$-$v_{\rm max}$ that derive from simulations observations....
ABSTRACT Collisionless dark matter only (DMO) structure formation simulations predict that (DM) haloes are prolate in their centres and triaxial towards outskirts. The addition of gas condensation transforms the central DM shape to be rounder more oblate. It is not clear, however, whether such transformations occur ‘ultra-faint’ dwarfs, which have extremely low baryon fractions. We present first study velocity anisotropy ultra-faint dwarf galaxies mass fractions fgas(r < Rhalf) 0.06....
ABSTRACT The Eridanus II (EriII) ‘ultra-faint’ dwarf has a large (15 pc) and low-mass (4.3 × 103 M⊙) star cluster (SC) offset from its centre by 23 ± 3 pc in projection. Its size are naturally explained if EriII central dark matter core, but such core may be challenging to explain ΛCDM cosmology. In this paper, we revisit the survival evolution of EriII’s SC, focusing for first time on puzzlingly ellipticity ($0.31^{+0.05}_{-0.06}$). We perform suite 960 direct N-body simulations SCs,...
We study feedback-driven cold dark matter core creation in the EDGE suite of radiation-hydrodynamical dwarf galaxy simulations. Understanding this process is crucial when using observed galaxies to constrain particle nature matter. While previous studies have shown stellar-mass halo-mass ratio $(M_{\star} / M_{200})$ determines extent creation, we find that low-mass dwarfs there a additional effect, namely timing star formation relative reionisation. Sustained post-reionisation decreases...
Collisionless Dark Matter Only (DMO) structure formation simulations predict that (DM) haloes are prolate in their centres and triaxial towards outskirts. The addition of gas condensation transforms the central DM shape to be rounder more oblate. It is not clear, however, whether such transformations occur `ultra-faint' dwarfs, which have extremely low baryon fractions. We present first study velocity anisotropy ultra-faint dwarf galaxies mass fractions $f_{\rm gas}(r<R_{\rm half}) < 0.06$....