57 research outputs found
An Innovative Workspace for The Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) is an initiative to build the next
generation, ground-based gamma-ray observatories. We present a prototype
workspace developed at INAF that aims at providing innovative solutions for the
CTA community. The workspace leverages open source technologies providing web
access to a set of tools widely used by the CTA community. Two different user
interaction models, connected to an authentication and authorization
infrastructure, have been implemented in this workspace. The first one is a
workflow management system accessed via a science gateway (based on the Liferay
platform) and the second one is an interactive virtual desktop environment. The
integrated workflow system allows to run applications used in astronomy and
physics researches into distributed computing infrastructures (ranging from
clusters to grids and clouds). The interactive desktop environment allows to
use many software packages without any installation on local desktops
exploiting their native graphical user interfaces. The science gateway and the
interactive desktop environment are connected to the authentication and
authorization infrastructure composed by a Shibboleth identity provider and a
Grouper authorization solution. The Grouper released attributes are consumed by
the science gateway to authorize the access to specific web resources and the
role management mechanism in Liferay provides the attribute-role mapping
The MPI+CUDA Gaia AVU-GSR Parallel Solver in perspective of next-generation Exascale Infrastructures and new Green Computing milestones
We ported on the GPU with CUDA the Gaia Astrometric Verification Unit-Global Sphere Reconstruction (AVU-GSR) Parallel Solver. The code aims to find the astrometric parameters of ~10^8 stars in the Milky Way, the attitude and the instrumental settings of the Gaia satellite, and the global parameter of the PPN formalism, by solving a system of linear equations, × = , with the LSQR iterative algorithm. The coefficient matrix is large, having ~10^11 × 10^8 elements, and sparse. The CUDA code accelerates ≳ 14 times compared to the current version of the AVU-GSR code, parallelized on the CPU with MPI+OpenMP and in production since 2014. This acceleration factor is ~9.2 times larger than the one obtained with a preliminary GPU porting with OpenACC, equal to ~1.5. We obtained this result by running the codes on the CINECA SuperComputer Marconi100, that has 4 NVIDIA Volta V100 GPUs per node, where the MPI+CUDA application has been recently put in production. This analysis represents a first step to understand the exascale behaviour of a class of applications that follow the same structure of this code, employed in several contexts. In the next months, we plan to run this code on the pre-exascale platform Leonardo of CINECA, with 4 next-generation A100 GPUs per node, to better investigate this behaviour. Computing on highly parallel devices, such as GPUs, might imply a consistent power saving, which might go towards the achievement of a Green Computing milestone
The Global sphere reconstruction (GSR) - Demonstrating an independent implementation of the astrometric core solution for Gaia
Context. The Gaia ESA mission will estimate the astrometric and physical data
of more than one billion objects, providing the largest and most precise
catalog of absolute astrometry in the history of Astronomy. The core of this
process, the so-called global sphere reconstruction, is represented by the
reduction of a subset of these objects which will be used to define the
celestial reference frame. As the Hipparcos mission showed, and as is inherent
to all kinds of absolute measurements, possible errors in the data reduction
can hardly be identified from the catalog, thus potentially introducing
systematic errors in all derived work. Aims. Following up on the lessons
learned from Hipparcos, our aim is thus to develop an independent sphere
reconstruction method that contributes to guarantee the quality of the
astrometric results without fully reproducing the main processing chain.
Methods. Indeed, given the unfeasibility of a complete replica of the data
reduction pipeline, an astrometric verification unit (AVU) was instituted by
the Gaia Data Processing and Analysis Consortium (DPAC). One of its jobs is to
implement and operate an independent global sphere reconstruction (GSR),
parallel to the baseline one (AGIS, namely Astrometric Global Iterative
Solution) but limited to the primary stars and for validation purposes, to
compare the two results, and to report on any significant differences. Results.
Tests performed on simulated data show that GSR is able to reproduce at the
sub-as level the results of the AGIS demonstration run presented in
Lindegren et al. (2012). Conclusions. Further development is ongoing to improve
on the treatment of real data and on the software modules that compare the AGIS
and GSR solutions to identify possible discrepancies above the tolerance level
set by the accuracy of the Gaia catalog.Comment: Accepted for publication on Astronomy & Astrophysic
Prospects for Weak Lensing surveys with next-generation arrays
Recently, R. Cen (2006) has suggested that small protogalactic halos at high redshift (z ' 20− 25) could be surrounded by extended (r ≈ 1h−1Mpc) gaseous halos, which could be marginally detected by LOFAR. However, more recent work on the mass function at high z shows that these estimates could be too optimistic. Moreover, the variance over the sky of this signal could be very large, thus undermining the practical usage of these halos for the determination of cosmological parameters using weak lensing
The MPI + CUDA Gaia AVU-GSR Parallel Solver Toward Next-generation Exascale Infrastructures
We ported to the GPU with CUDA the Astrometric Verification Unit-Global
Sphere Reconstruction (AVU-GSR) Parallel Solver developed for the ESA Gaia
mission, by optimizing a previous OpenACC porting of this application. The code
aims to find, with a [10,100]as precision, the astrometric parameters of
stars, the attitude and instrumental settings of the Gaia
satellite, and the global parameter of the parametrized Post-Newtonian
formalism, by solving a system of linear equations, , with the
LSQR iterative algorithm. The coefficient matrix of the final Gaia dataset
is large, with elements, and sparse, reaching a
size of 10-100 TB, typical for the Big Data analysis, which requires an
efficient parallelization to obtain scientific results in reasonable
timescales. The speedup of the CUDA code over the original AVU-GSR solver,
parallelized on the CPU with MPI+OpenMP, increases with the system size and the
number of resources, reaching a maximum of 14x, >9x over the OpenACC
application. This result is obtained by comparing the two codes on the CINECA
cluster Marconi100, with 4 V100 GPUs per node. After verifying the agreement
between the solutions of a set of systems with different sizes computed with
the CUDA and the OpenMP codes and that the solutions showed the required
precision, the CUDA code was put in production on Marconi100, essential for an
optimal AVU-GSR pipeline and the successive Gaia Data Releases. This analysis
represents a first step to understand the (pre-)Exascale behavior of a class of
applications that follow the same structure of this code. In the next months,
we plan to run this code on the pre-Exascale platform Leonardo of CINECA, with
4 next-generation A200 GPUs per node, toward a porting on this infrastructure,
where we expect to obtain even higher performances.Comment: 17 pages, 4 figures, 1 table, published on 1st August 2023 in
Publications of the Astronomical Society of the Pacific, 135, 07450
Toward porting Astrophysics Visual Analytics Services to the European Open Science Cloud
The European Open Science Cloud (EOSC) aims to create a federated environment
for hosting and processing research data to support science in all disciplines
without geographical boundaries, such that data, software, methods and
publications can be shared as part of an Open Science community of practice.
This work presents the ongoing activities related to the implementation of
visual analytics services, integrated into EOSC, towards addressing the diverse
astrophysics user communities needs. These services rely on visualisation to
manage the data life cycle process under FAIR principles, integrating data
processing for imaging and multidimensional map creation and mosaicing, and
applying machine learning techniques for detection of structures in large scale
multidimensional maps
astrophysical data analysis and visualization toolkit
AstroMD is a visualization software offering several capabilities specifically oriented to the cosmological analysis of three-dimensional structures. It was developed within the framework of the Cosmo.Lab project, financially supported by the European Community, which involves several European Astrophysical Institutions and the CINECA. This tool gives a 3D graphic representation of data, exploiting the most advanced visualization technology based on virtual reality, and has several built-in-tools which allow the user an efficient manipulation and analysis of data, in order to build a leading edge instrument for scientific research. It was developed using the Visualization Toolkit (VTK) by Kitware, a freely available visualization library portable on many platforms. AstroMD is an open source freely available code at the address http://cosmolab.cineca.it/
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