Filter and export

Publications

What is a Publication?
69 Publications visible to you, out of a total of 69
Redesign of astrophysical codes for exascale computing: the SPACE experience

Abstract

Not specified

Authors: Giuliano Taffoni, Andrea Mignone, Luca Tornatore, Eva Sciacca, Massimiliano Guarrasi, Giovanni Lapenta, Lubomir Riha, Radim Vavrik, Ondrej Vysocky, Kristian Kadlubiak, Petr Strakos, Milan Jaros, Klaus Dolag, Benoit Commercon, Luciano Rezzolla, Khalil Pierre, Georgios Doulis, Sijing Shen, Manolis Marazakis, Daniele Gregori, Elisabetta Boella, Gino Perna, Marisa Zanotti, Erwan Raffin, Kai Polsterer, Sebastian Trujillo Gomez, Guillermo Marin

Date Published: 18th Jul 2024

Publication Type: Journal

H  i discs of L* galaxies as probes of the baryonic physics of galaxy evolution

Abstract (Expand)

ABSTRACT Understanding what shapes the cold gas component of galaxies, which both provides the fuel for star formation and is strongly affected by the subsequent stellar feedback, is a crucial step …eedback, is a crucial step towards a better understanding of galaxy evolution. Here, we analyse the H i properties of a sample of 46 Milky Way halo-mass galaxies, drawn from cosmological simulations (EMP-Pathfinder and Firebox). This set of simulations comprises galaxies evolved self-consistently across cosmic time with different baryonic sub-grid physics: three different star formation models [constant star formation efficiency (SFE) with different star formation eligibility criteria, and an environmentally dependent, turbulence-based SFE] and two different feedback prescriptions, where only one sub-sample includes early stellar feedback. We use these simulations to assess the impact of different baryonic physics on the H i content of galaxies. We find that the galaxy-wide H i properties agree with each other and with observations. However, differences appear for small-scale properties. The thin H i discs observed in the local universe are only reproduced with a turbulence-dependent SFE and/or early stellar feedback. Furthermore, we find that the morphology of H i discs is particularly sensitive to the different physics models: galaxies simulated with a turbulence-based SFE have discs that are smoother and more rotationally symmetric, compared to those simulated with a constant SFE; galaxies simulated with early stellar feedback have more regular discs than supernova-feedback-only galaxies. We find that the rotational asymmetry of the H i discs depends most strongly on the underlying physics model, making this a promising observable for understanding the physics responsible for shaping the interstellar medium of galaxies.

Authors: Jindra Gensior, Robert Feldmann, Marta Reina-Campos, Sebastian Trujillo-Gomez, Lucio Mayer, Benjamin W Keller, Andrew Wetzel, J M Diederik Kruijssen, Philip F Hopkins, Jorge Moreno

Date Published: 1st Jun 2024

Publication Type: Journal

Spherinator and HiPSter: Representation Learning for Unbiased Knowledge Discovery from Simulations

Abstract

Not specified

Authors: Kai L. Polsterer, Bernd Doser, Andreas Fehlner, Sebastian Trujillo-Gomez

Date Published: 1st Jun 2024

Publication Type: Journal

On the origin of globular clusters in a hierarchical universe

Abstract (Expand)

ABSTRACT We present an end-to-end description of the formation of globular clusters (GCs) combining a treatment for their formation and dynamical evolution within galaxy haloes with a state-of-the-art …es with a state-of-the-art semi-analytic simulation of galaxy formation. Our approach allows us to obtain exquisite statistics to study the effect of the environment and assembly history of galaxies, while still allowing a very efficient exploration of the parameter space. Our reference model, including both efficient cluster disruption during galaxy mergers and dynamical friction of GCs within the galactic potential, accurately reproduces the observed correlation between the total mass in GCs and the parent halo mass. A deviation from linearity is predicted at low-halo masses, which is driven by a strong dependence on morphological type: bulge-dominated galaxies tend to host larger masses of GCs than their later-type counterparts. While the significance of the difference might be affected by resolution at the lowest halo masses considered, this is a robust prediction of our model and a natural consequence of the assumption that cluster migration into the halo is triggered by galaxy mergers. Our model requires an environmental dependence of GC radii to reproduce the observed low-mass mass distribution of GCs in our Galaxy. At GC masses $\gt 10^6\, {\rm M}_\odot$, our model predicts fewer GCs than observed, due to an overly aggressive treatment of dynamical friction. Our model reproduces well the metallicity distribution measured for Galactic GCs, even though we predict systematically younger GCs than observed. We argue that this adds further evidence for an anomalously early formation of the stars in our Galaxy.

Authors: Gabriella De Lucia, J M Diederik Kruijssen, Sebastian Trujillo-Gomez, Michaela Hirschmann, Lizhi Xie

Date Published: 1st May 2024

Publication Type: Journal

Rotation and flipping invariant self-organizing maps with astronomical images: A cookbook and application to the VLA Sky Survey QuickLook images

Abstract

Not specified

Authors: A.N. Vantyghem, T.J. Galvin, B. Sebastian, C.P. O’Dea, Y.A. Gordon, M. Boyce, L. Rudnick, K. Polsterer, H. Andernach, M. Dionyssiou, P. Venkataraman, R. Norris, S.A. Baum, X.R. Wang, M. Huynh

Date Published: 1st Apr 2024

Publication Type: Journal

Reevaluating LSST’s Capability for Time Delay Measurements in Quasar Accretion Disks

Abstract (Expand)

Abstract The Legacy Survey of Space and Time at the Vera C. Rubin Observatory is poised to observe thousands of quasars using the Deep Drilling Fields (DDF) across six broadband filters over a decade. …and filters over a decade. Understanding quasar accretion disk (AD) time delays is pivotal for probing the physics of these distant objects. Pozo Nuñez et al. has recently demonstrated the feasibility of recovering AD time delays with accuracies ranging from 5% to 20%, depending on the quasar’s redshift and time sampling intervals. Here we reassess the potential for measuring AD time delays under the current DDF observing cadence, which is placeholder until a final cadence is decided. We find that contrary to prior expectations, achieving reliable AD time delay measurements for quasars is significantly more challenging, if not unfeasible, due to the limitations imposed by the current observational strategies.

Authors: F. Pozo Nuñez, B. Czerny, S. Panda, A. Kovacevic, W. Brandt, K. Horne

Date Published: 14th Feb 2024

Publication Type: Journal

Examining quasar absorption-line analysis methods: the tension between simulations and observational assumptions key to modelling clouds

Abstract (Expand)

ABSTRACT A key assumption in quasar absorption-line studies of the circumgalactic medium (CGM) is that each absorption component maps to a spatially isolated ‘cloud’ structure that has single valued …ure that has single valued properties (e.g. density, temperature, metallicity). We aim to assess and quantify the degree of accuracy underlying this assumption. We used adaptive mesh refinement hydrodynamic cosmological simulations of two z = 1 dwarf galaxies and generated synthetic quasar absorption-line spectra of their CGM. For the Si ii λ1260 transition, and the C iv λλ1548, 1550 and O vi λλ1031, 1037 fine-structure doublets, we objectively determined which gas cells along a line of sight (LOS) contribute to detected absorption. We implemented a fast, efficient, and objective method to define individual absorption components in each absorption profile. For each absorption component, we quantified the spatial distribution of the absorbing gas. We studied a total of 1302 absorption systems containing a total of 7755 absorption components. 48  per cent of Si ii, 68  per cent of C iv, and 72  per cent of O vi absorption components arise from two or more spatially isolated ‘cloud’ structures along the LOS. Spatially isolated ‘cloud’ structures were most likely to have cloud–cloud LOS separations of 0.03Rvir (1.3 kpc), 0.11Rvir (4.8 kpc), and 0.13Rvir (5.6 kpc) for Si ii, C iv, and O vi, respectively. There can be very little overlap between multiphase gas structures giving rise to absorption components. If our results reflect the underlying reality of how absorption lines record CGM gas, they place tension on current observational analysis methods as they suggest that component-by-component absorption-line formation is more complex than is assumed and applied for chemical-ionization modelling.

Authors: Rachel Marra, Christopher W Churchill, Glenn G Kacprzak, Nikole M Nielsen, Sebastian Trujillo-Gomez, Emmy A Lewis

Date Published: 1st Feb 2024

Publication Type: Journal

Powered by
 (v.1.15.2)
About HITS Publication SEEK | About HITS-Publication-SEEK | Funding and Programmes | Credits
Copyright © 2008 - 2024 The University of Manchester and HITS gGmbH