A5054987261- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Genomics and Phylogenetic Studies
- Scientific Research and Discoveries
- Genetic diversity and population structure
- Remote Sensing in Agriculture
- X-ray Spectroscopy and Fluorescence Analysis
- Isotope Analysis in Ecology
- Astro and Planetary Science
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Methane Hydrates and Related Phenomena
- Nuclear physics research studies
- Plant Diversity and Evolution
- SAS software applications and methods
- Electron and X-Ray Spectroscopy Techniques
- Plant Water Relations and Carbon Dynamics
- Mass Spectrometry Techniques and Applications
- Cephalopods and Marine Biology
University of Hertfordshire
2022-2025
University of Surrey
2021-2024
Max Planck Institute for Astrophysics
2012-2021
Max Planck Institute for Extraterrestrial Physics
2016-2019
Max Planck Society
2013-2018
We study relations between stellar mass, star formation and gas-phase metallicity in a sample of 177 071 unique emission line galaxies from the Sloan Digital Sky Survey Data Release 7, as well 43 767 star-forming at z= 0 cosmological semi-analytic model l-galaxies. demonstrate that is dependent on rate fixed but trend opposite for low high mass galaxies. Low-mass are actively forming stars more metal poor than quiescent low-mass High-mass galaxies, other hand, have lower metallicities if...
ABSTRACT We have updated the Munich galaxy formation model, L-galaxies, to follow radial distributions of stars and atomic molecular gas in discs. include an H2-based star-formation law, as well a detailed chemical-enrichment model with explicit mass-dependent delay times for SN-II, SN-Ia, AGB stars. Information about star formation, feedback, histories discs is stored 12 concentric rings. The new retains success its predecessor reproducing observed evolution population, particular, stellar...
We update the treatment of chemical evolution in Munich semi-analytic model, L-GALAXIES. Our new implementation includes delayed enrichment from stellar winds, supernovae type II (SNe-II) and Ia (SNe-Ia), as well metallicity-dependent yields a reformulation associated supernova feedback. Two different sets SN-II three SN-Ia delay-time distributions (DTDs) are considered, eleven heavy elements (including O, Mg Fe) self-consistently tracked. compare results this with data on a) local,...
We have updated our radially resolved semi-analytic models (SAMs) of galaxy formation, which track both the atomic and molecular gas phases interstellar medium. The are adapted from those Guo et al. using similar methodology as by Fu run on halo merger trees Millennium Millennium-II simulations with following main changes. (1) adopt a simple star formation law ΣSFR ∝ ΣH2. (2) inject heavy elements produced supernovae directly into hot gas, instead first mixing them cold in disc. (3) include...
Host galaxy properties provide strong constraints on the stellar progenitors of superluminous supernovae. By comparing a sample 19 low-redshift (z < 0.3) supernova hosts to populations in local Universe, we show that sub-solar metallicities seem be requirement. All supernovae with high measured gas-phase are found explode at large galactocentric radii, indicating metallicity explosion site is likely lower than integrated host value. We do not always have star-formation rates higher typical...
In this study we investigate the relation between stellar mass, dust extinction and star formation rate (SFR) using ~150,000 star-forming galaxies from SDSS DR7. We show that SFR changes with mass. For at same mass is anti-correlated masses <10^10 M_solar. There a sharp transition in of 10^10 At larger positively correlated for The observed presented helps to confirm similar trends metallicity SFR. reported provides important new constraints on physical processes governing chemical evolution...
ABSTRACT We implement a detailed dust model into the L-Galaxies semi-analytical which includes: injection of by type II and Ia supernovae (SNe) AGB stars; grain growth in molecular clouds; destruction due to supernova-induced shocks, star formation, reheating. Our follows content clouds inter-cloud medium separately, allows only on pre-existing grains. At early times, this can make significant difference rate. Above z ∼ 8, SNe are primary source dust, whereas below dominates, with total...
We present and analyse an extensive dataset of the superluminous supernova (SLSN) LSQ14mo (z = 0.256), consisting a multi-colour lightcurve from -30 d to +70 in rest-frame series 6 spectra PESSTO covering -7 +50 d. This is among densest spectroscopic coverage, best-constrained rising lightcurve, for fast-declining hydrogen-poor SLSN. The bolometric can be reproduced with millisecond magnetar model ~ 4 M_sol ejecta mass, temperature velocity evolution also suggestive as power source. Spectral...
We present a modified version of the L-GALAXIES 2020 semi-analytic model galaxy evolution, which includes significantly increased direct metal enrichment circumgalactic medium (CGM) by supernovae (SNe). These more metal-rich outflows do not require mass-loading factors, in contrast to some other evolution models. This is able simultaneously reproduce gas-phase metallicity $(Z_{\rm g})$ and stellar $(Z_{*})$ radial profiles observed nearby disc galaxies MaNGA MUSE, as well mass - relations...
Context. Several issues regarding the nature of dust at high redshift remain unresolved: its composition, production and growth mechanisms, effect on background sources. Aims. We provide a more accurate relation between depletion levels dust-to-metals ratio (DTM), to use DTM investigate origin evolution in high-redshift Universe via Gamma-ray burst damped Lyman-alpha absorbers (GRB-DLAs). Methods. absorption-line measured metal column densities for total 19 GRB-DLAs, including five new GRB...
We report on the detection of a bright, short, structured X-ray burst coming from supernova remnant RCW 103 2016 June 22 caught by Swift/BAT monitor, and follow-up campaign made with Swift/XRT, Swift/UVOT optical/NIR GROND detector. The characteristics this flash, such as duration, spectral shape, are consistent typical short bursts observed soft gamma repeaters. BAT error circle at 68 per cent confidence range encloses point-like source centre nebula, 1E161348-5055. Its nature has been long...
We investigate electron temperature (Te) and gas-phase oxygen abundance (Z_Te) measurements for galaxies in the local Universe (z < 0.25). Our sample comprises spectra from a total of 264 emission-line systems, ranging individual HII regions to whole galaxies, including 23 composite "star-forming main sequence" MaNGA survey. utilise 130 these systems with directly measurable Te(OII) calibrate new metallicity-dependent Te(OIII) - relation that provides better representation our varied dataset...
We present a variation of the recently updated Munich semi-analytical galaxy formation model, L-Galaxies, with new gas stripping method. Extending earlier work, we directly measure local environmental properties galaxies to formulate more accurate treatment ram-pressure for all galaxies. fully re-calibrate modified L-Galaxies model using Markov Chain Monte Carlo (MCMC) method stellar mass function and quenched fraction at $0\leq z\leq2$ as constraints. Due this re-calibration, global...
We perform a comparison, object-by-object and statistically, between the Munich semi-analytical model, L-Galaxies, IllustrisTNG hydrodynamical simulations. By running L-Galaxies on dark matter-only merger trees, we identify same galaxies in two models. This allows us to compare stellar mass, star formation rate gas content of galaxies, as well baryonic subhaloes haloes find that both mass functions masses individual agree better than $\sim0.2\,$dex. On other hand, specific rates contents can...
Short Gamma-Ray Bursts (SGRBs) are produced by the coalescence of compact binary systems which remnants massive stars. GRB 160410A is classified as a short-duration with extended emission and currently farthest SGRB redshift determined from an afterglow spectrum also one brightest SGRBs to date. The fast reaction Neil Gehrels Swift Observatory alert allowed us obtain using X-shooter spectrograph at Very Large Telescope (VLT). shows several absorption features z=1.7177, in addition, we detect...
<title>Abstract</title> The nature and formation history of our Galaxy's largest most enigmatic stellar cluster, known as Omega Centauri (oCen) remains debated. Here, we offer a novel approach to disentangling the complex populations within oCen based on phylogenetics methodologies from evolutionary biology. These include Gaussian Mixture Model Neighbor-Joining clustering algorithms applied set chemical abundances members. Instead using classical in astronomy grouping them into separate...
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...
We present here the characterization of main properties a sample 98 AGN host galaxies, both type-II and type-I, in comparison with those about 2700 non-active galaxies observed by MaNGA survey. found that hosts are morphologically early-type or early-spirals. For given morphology are, average, more massive, compact, central peaked rather pressurethan rotational-supported systems. confirm previous results indicating located intermediate/transition region between star-forming non-star-forming...
We present an analysis of the iron abundance in hot gas surrounding galaxy groups and clusters. To do this, we first compile homogenise a large dataset 79 low-redshift (|z| = 0.03) systems (159 individual measurements) from literature. Our accounts for differences aperture size, solar abundance, cosmology, scales all measurements using customised radial profiles temperature (T), density, (Z). then compare this to clusters L-Galaxies evolution model. homogenised reveals tight T-Z relation...
We introduce a local background environment (LBE) estimator that can be measured in and around every galaxy or its dark matter subhalo high-resolution cosmological simulations. The LBE is designed to capture the influence of environmental effects such as ram-pressure stripping (RPS) on formation evolution galaxies semi-analytical models. define directly from particle data within an adaptive spherical shell, devise Gaussian mixture separate particles previously unidentified particles....
ABSTRACT Stellar chemical abundances have proved themselves a key source of information for understanding the evolution Milky Way, and scale major stellar surveys such as GALAH massively increased amount data available. However, progress is hampered by level precision in abundance well visualization methods comparing multidimensional outputs models to data. Machine learning greatly improved former; while application tree-building or phylogenetic borrowed from biology are beginning show...
ABSTRACT Much of what is known the chemical composition universe based on emission line spectra from star-forming galaxies. Emission-based inferences are, nevertheless, model-dependent and they are dominated by light luminous regions. An alternative sensitive probe metallicity galaxies through absorption lines imprinted afterglow long gamma ray bursts (GRBs) neutral material within their host galaxy. We present results a JWST/NIRSpec programme to investigate for first time relation between...
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...
ABSTRACT We present detailed implementations of (i) binary stellar evolution (BSE; using binary_c) and (ii) dust production destruction into the cosmological semi-analytic galaxy simulation, l-galaxies. This new version l-galaxies is compared to a assuming only single stars global spatially-resolved observational data across range redshifts (z). find that binaries have negligible impact on masses, gas star formation rates galaxies if total mass ejected by massive unchanged. because determine...