70 research outputs found
Astrophysical code migration into Exascale Era
The ExaNeSt and EuroExa H2020 EU-funded projects aim to design and develop an
exascale ready computing platform prototype based on low-energy-consumption
ARM64 cores and FPGA accelerators. We participate in the application-driven
design of the hardware solutions and prototype validation. To carry on this
work we are using, among others, Hy-Nbody, a state-of-the-art direct N-body
code. Core algorithms of Hy-Nbody have been improved in such a way to
increasingly fit them to the exascale target platform. Waiting for the ExaNest
prototype release, we are performing tests and code tuning operations on an
ARM64 SoC facility: a SLURM managed HPC cluster based on 64-bit ARMv8
Cortex-A72/Cortex-A53 core design and powered by a Mali-T864 embedded GPU. In
parallel, we are porting a kernel of Hy-Nbody on FPGA aiming to test and
compare the performance-per-watt of our algorithms on different platforms. In
this paper we describe how we re-engineered the application and we show first
results on ARM SoC.Comment: 4 pages, 1 figure, 1 table; proceedings of ADASS XXVIII, accepted by
ASP Conference Serie
The MORGANA model for the rise of galaxies and active nuclei
We present the MOdel for the Rise of GAlaxies aNd Active nuclei (MORGANA).
Starting from the merger trees of dark matter halos and a model for the
evolution of substructure within the halos, the complex physics of baryons is
modeled with a set of state-of-the-art models that describe the mass, metal and
energy flows between the various components and phases of a galaxy. The
processes of shock-heating and cooling, star formation, feedback, galactic
winds and super-winds, accretion onto BHs and AGN feedback are described by new
models. In particular, the evolution of the halo gas explicitly follows the
thermal and kinetic energies of the hot and cold phases, while star formation
and feedback follow the results of the multi-phase model by Monaco (2004a). The
increased level of sophistication allows to move from a phenomenological
description of gas physics, based on simple scalings with the depth of the DM
halo potential, toward a fully physically motivated one. The comparison of the
predictions of MORGANA with a basic set of galactic data reveals from the one
hand an overall rough agreement, and from the other hand highlights a number of
well- or less-known problems: (i) producing the cutoff of the luminosity
function requires to force the quenching of the late cooling flows by AGN
feedback, (ii) the normalization of the Tully-Fisher relation of local spirals
cannot be recovered unless the dark matter halos are assumed to have a very low
concentration, (iii) the mass function of HI gas is not easily fitted at small
masses, unless a similarly low concentration is assumed, (iv) there is an
excess of small elliptical galaxies at z=0. These discrepancies, more than the
points of agreement with data, give important clues on the missing ingredients
of galaxy formation. (ABRIDGED)Comment: 35 pages, figures included, uses mn2e.cls. Revised cooling model,
results are slightly changed, conclusions are unchanged. MNRAS, in pres
Interoperable geographically distributed astronomical infrastructures: technical solutions
The increase of astronomical data produced by a new generation of
observational tools poses the need to distribute data and to bring computation
close to the data. Trying to answer this need, we set up a federated data and
computing infrastructure involving an international cloud facility, EGI
federated, and a set of services implementing IVOA standards and
recommendations for authentication, data sharing and resource access. In this
paper we describe technical problems faced, specifically we show the designing,
technological and architectural solutions adopted. We depict our technological
overall solution to bring data close to computation resources. Besides the
adopted solutions, we propose some points for an open discussion on
authentication and authorization mechanisms.Comment: 4 pages, 1 figure, submitted to Astronomical Society of the Pacific
(ASP
IVOA Recommendation: IVOA Credential Delegation Protocol Version 1.0
The credential delegation protocol allows a client program to delegate a
user's credentials to a service such that that service may make requests of
other services in the name of that user. The protocol defines a REST service
that works alongside other IVO services to enable such a delegation in a secure
manner. In addition to defining the specifics of the service protocol, this
document describes how a delegation service is registered in an IVOA registry
along with the services it supports. The specification also explains how one
can determine from a service registration that it requires the use of a
supporting delegation service
Rosetta: a container-centric science platform for resource-intensive, interactive data analysis
Rosetta is a science platform for resource-intensive, interactive data analysis which runs user tasks as software containers. It is built on top of a novel architecture based on framing user tasks as microservices - independent and self-contained units - which allows to fully support custom and user-defined software packages, libraries and environments. These include complete remote desktop and GUI applications, besides common analysis environments as the Jupyter Notebooks. Rosetta relies on Open Container Initiative containers, which allow for safe, effective and reproducible code execution; can use a number of container engines and runtimes; and seamlessly supports several workload management systems, thus enabling containerized workloads on a wide range of computing resources. Although developed in the astronomy and astrophysics space, Rosetta can virtually support any science and technology domain where resource-intensive, interactive data analysis is required
Cloud Computing for Astronomers on Top of EGI Federated Cloud
EGI Federated Cloud offers a general academic Cloud Infrastructure. We exploit EGI functionalities to address the needs of representative Astronomy and Astrophysics communities through clouds and gateways while respecting commonly used standards. The vision is to offer a novel environment empowering scientists to focus more on experimenting and pitching new ideas to service their needs for scientific discovery
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