153 research outputs found
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FabSim3: An automation toolkit for verified simulations using high performance computing
A common feature of computational modelling and simulation research is the need to perform many
tasks in complex sequences to achieve a usable result. This will typically involve tasks such as preparing
input data, pre-processing, running simulations on a local or remote machine, post-processing, and
performing coupling communications, validations and/or optimisations. Tasks like these can involve
manual steps which are time and effort intensive, especially when it involves the management of large
ensemble runs. Additionally, human errors become more likely and numerous as the research work
becomes more complex, increasing the risk of damaging the credibility of simulation results. Automation
tools can help ensure the credibility of simulation results by reducing the manual time and effort
required to perform these research tasks, by making more rigorous procedures tractable, and by reducing
the probability of human error due to a reduced number of manual actions. In addition, efficiency
gained through automation can help researchers to perform more research within the budget and effort
constraints imposed by their projects.
This paper presents the main software release of FabSim3, and explains how our automation toolkit
can improve and simplify a range of tasks for researchers and application developers. FabSim3 helps
to prepare, submit, execute, retrieve, and analyze simulation workflows. By providing a suitable level
of abstraction, FabSim3 reduces the complexity of setting up and managing a large-scale simulation
scenario, while still providing transparent access to the underlying layers for effective debugging.
The tool also facilitates job submission and management (including staging and curation of files
and environments) for a range of different supercomputing environments. Although FabSim3 itself is
application-agnostic, it supports a provably extensible plugin system where users automate simulation
and analysis workflows for their own application domains. To highlight this, we briefly describe a
selection of these plugins and we demonstrate the efficiency of the toolkit in handling large ensemble
workflows.EPSRC under grant agreement EP/W007711/1, as well as by the VECMA and HiDALGO projects, which have
received funding from the European Union Horizon 2020 research and innovation programme under grant agreement nos 800925 and
824115. In addition, FabFlee was supported by the ITFLOWS project and FabCovid19 by the STAMINA project, both of which have received
funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 882986 and No 883441
respectivel
Mass and Hot Baryons in Massive Galaxy Clusters from Subaru Weak Lensing and AMiBA SZE Observations
We present a multiwavelength analysis of a sample of four hot (T_X>8keV)
X-ray galaxy clusters (A1689, A2261, A2142, and A2390) using joint AMiBA
Sunyaev-Zel'dovich effect (SZE) and Subaru weak lensing observations, combined
with published X-ray temperatures, to examine the distribution of mass and the
intracluster medium (ICM) in massive cluster environments. Our observations
show that A2261 is very similar to A1689 in terms of lensing properties. Many
tangential arcs are visible around A2261, with an effective Einstein radius
\sim 40 arcsec (at z \sim 1.5), which when combined with our weak lensing
measurements implies a mass profile well fitted by an NFW model with a high
concentration c_{vir} \sim 10, similar to A1689 and to other massive clusters.
The cluster A2142 shows complex mass substructure, and displays a shallower
profile (c_{vir} \sim 5), consistent with detailed X-ray observations which
imply recent interaction. The AMiBA map of A2142 exhibits an SZE feature
associated with mass substructure lying ahead of the sharp north-west edge of
the X-ray core suggesting a pressure increase in the ICM. For A2390 we obtain
highly elliptical mass and ICM distributions at all radii, consistent with
other X-ray and strong lensing work. Our cluster gas fraction measurements,
free from the hydrostatic equilibrium assumption, are overall in good agreement
with published X-ray and SZE observations, with the sample-averaged gas
fraction of = 0.133 \pm 0.027, for our sample = (1.2 \pm
0.1) \times 10^{15} M_{sun} h^{-1}. When compared to the cosmic baryon fraction
f_b = \Omega_b/\Omega_m constrained by the WMAP 5-year data, this indicates
/f_b = 0.78 \pm 0.16, i.e., (22 \pm 16)% of the baryons are missing
from the hot phase of clusters.Comment: accepted for publication in ApJ; high resolution figures available at
http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/AMiBA7/ms_highreso.pd
The Yuan-Tseh Lee Array for Microwave Background Anisotropy
The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) is the
first interferometer dedicated to studying the cosmic microwave background
(CMB) radiation at 3mm wavelength. The choice of 3mm was made to minimize the
contributions from foreground synchrotron radiation and Galactic dust emission.
The initial configuration of seven 0.6m telescopes mounted on a 6-m hexapod
platform was dedicated in October 2006 on Mauna Loa, Hawaii. Scientific
operations began with the detection of a number of clusters of galaxies via the
thermal Sunyaev-Zel'dovich effect. We compare our data with Subaru weak lensing
data in order to study the structure of dark matter. We also compare our data
with X-ray data in order to derive the Hubble constant.Comment: accepted for publication in ApJ (13 pages, 7 figures); a version with
high resolution figures available at
http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/AMiBA7/pho_highreso.pd
Absolute Flux Density Calibration of the Greenland Telescope Data for Event Horizon Telescope Observations
Starting from the observing campaign in April 2018, the Greenland Telescope
(GLT) has been added as a new station of the Event Horizon Telescope (EHT)
array. Visibilities on baselines to the GLT, particularly in the North-South
direction, potentially provide valuable new constraints for the modeling and
imaging of sources such as M87*. The GLT's location at high Northern latitudes
adds unique challenges to its calibration strategies. Additionally, the
performance of the GLT was not optimal during the 2018 observations due to it
being only partially commissioned at the time. This document describes the
steps taken to estimate the various parameters (and their uncertainties)
required for the absolute flux calibration of the GLT data as part of the EHT.
In particular, we consider the non-optimized status of the GLT in 2018, as well
as its improved performance during the 2021 EHT campaign.Comment: 17 pages, 4 figures, EHT Memo Series 2023-L1-0
FabSim3: An automation toolkit for verified simulations using high performance computing
A common feature of computational modelling and simulation research is the need to perform many tasks in complex sequences to achieve a usable result. This will typically involve tasks such as preparing input data, pre-processing, running simulations on a local or remote machine, post-processing, and performing coupling communications, validations and/or optimisations. Tasks like these can involve manual steps which are time and effort intensive, especially when it involves the management of large ensemble runs. Additionally, human errors become more likely and numerous as the research work becomes more complex, increasing the risk of damaging the credibility of simulation results. Automation tools can help ensure the credibility of simulation results by reducing the manual time and effort required to perform these research tasks, by making more rigorous procedures tractable, and by reducing the probability of human error due to a reduced number of manual actions. In addition, efficiency gained through automation can help researchers to perform more research within the budget and effort constraints imposed by their projects. This paper presents the main software release of FabSim3, and explains how our automation toolkit can improve and simplify a range of tasks for researchers and application developers. FabSim3 helps to prepare, submit, execute, retrieve, and analyze simulation workflows. By providing a suitable level of abstraction, FabSim3 reduces the complexity of setting up and managing a large-scale simulation scenario, while still providing transparent access to the underlying layers for effective debugging. The tool also facilitates job submission and management (including staging and curation of files and environments) for a range of different supercomputing environments. Although FabSim3 itself is application-agnostic, it supports a provably extensible plugin system where users automate simulation and analysis workflows for their own application domains. To highlight this, we briefly describe a selection of these plugins and we demonstrate the efficiency of the toolkit in handling large ensemble workflows
AMiBA: Sunyaev-Zel'Dovich Effect-derived Properties and Scaling Relations of Massive Galaxy Clusters
99學年度劉國欽研究獎助論文
100學年度劉國欽升等參考著作[[abstract]]The Sunyaev-Zel'dovich Effect (SZE) has been observed toward six massive galaxy clusters, at redshifts 0.091 ≤ z ≤ 0.322 in the 86-102 GHz band with the Y. T. Lee Array for Microwave Background Anisotropy (AMiBA). We modify an iterative method, based on the isothermal β models, to derive the electron temperature T e, total mass M t, gas mass M g, and integrated Compton Y within r 2500, from the AMiBA SZE data. Non-isothermal universal temperature profile (UTP) β models are also considered in this paper. These results are in good agreement with those deduced from other observations. We also investigate the embedded scaling relations, due to the assumptions that have been made in the method we adopted, between these purely SZE-deduced T e, M t, M g, and Y. Our results suggest that cluster properties may be measurable with SZE observations alone. However, the assumptions built into the pure-SZE method bias the results of scaling relation estimations and need further study.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]US
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