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INAF Osservatorio Astrofisico di Catania
INAF Osservatorio Astrofisico di Catania Ugo
Becciani

• Cosmological simulations
• N-body and fluidodynamical
• simulations
• Scientific Visualization
• AstroMD tools
• Group of interest
• Testing and Validation

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INAF Osservatorio Astrofisico di Catania
COSMOLOGICAL SIMULATIONS
To calculate the age of the Universe use
Hubbles Law
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INAF Osservatorio Astrofisico di Catania
The Age of the Universe
For H070 km/s per megaparsec we have
T 1.40 x 1010 years 14.0 billion years
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INAF Osservatorio Astrofisico di Catania
The observational challenge

• Our view of the Large-Scale Structure of galaxy
• distribution has radically changed during the
• last 30 years

• Voids fill the
• Universe -Galaxies
• and their Clusters
• lie on walls and along filaments

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INAF Osservatorio Astrofisico di Catania
Why Dark Matter ?
90 of the total gravitating mass is invisible
(Dark Matter) Main evidence Galaxy rotation
curves

• DM dominates the
• dynamical evol.
• of our Universe
• DM is distributed
• inhomogeneously
• Even from CMBs
• observations we
• need DM

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INAF Osservatorio Astrofisico di Catania

• Gravitational instability ??/? 10-6 -103
• Voids expand ? increasing volume fraction
• Clusters contract ? increasing density

• Clusters and galaxies
• collapse ? almost relaxed
• final state
• Voids evolution strongly
• dependent on cosmological
• model

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INAF Osservatorio Astrofisico di Catania
The theoretical framework

• Dark Matter 3 types (Cold, Warm, Hot)
• CDM Mcoll 104 Msun
• WDM M coll 3106 Msun
• HDM M coll 5.5107 Msun

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INAF Osservatorio Astrofisico di Catania
Models of the Universe
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Models vs. simulations of LSS
SCDM bias 1
LCDM bias 1
Observed
SCDM bias 2
LCDM Bias 2
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INAF Osservatorio Astrofisico di Catania
Galaxy populations in voids

• High resolution simulation using FLY ?CDM,
  ?0.7,
• OM 0.3, L50 h1 Mpc

• Voids are threaded
• by filaments
• Clusters form at
• the intersection of
• filaments
• Galaxies in voids
• suffer lesser merging
• - only in filaments SF
• is triggered

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INAF Osservatorio Astrofisico di Catania
Topology of Isodensity surfaces

• Minkowski functionals
• characterize topology of
• LSS
• Clusters are already in
• linear phase simply
• connected

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INAF Osservatorio Astrofisico di Catania
Fluidodynamical Simulations
Gas and star formation. Mixed simulation using
gas, dark matter and stars to study the evolution
of a galaxy and the star formation processes
AGN (Active Galactic Nuclei) simulations giant
elliptical galaxies producing extremely powerful
outflows of emitting plasma, appearing as two
persistent, oppositely-directed jets that contain
cosmic ray electrons and magnetic fields.
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INAF Osservatorio Astrofisico di Catania
INAF Astrophysical Observatory of Catania

• 24 Processors
• Global RAM Memory 48 Gbyte
• Disk Space 254 GB (72.8 GB HD per node 36.2 GB
  HD cws)
• Network Topology SPS scalable Omega switch and
  FastEthernet node interconnection type
• Bandwidth 300 Mbyte/s peak bi-directional
  transfer rate
• Programming Language C, C, Fortran 90
• Parallel paradigms OpenMP, MPI, LAPI

IBM SP POWER3
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INAF Osservatorio Astrofisico di Catania
INAF Astrophysical Observatory of Catania

• NEW SYSTEM
• 8 Processors 1.1 GHz
• Global RAM Memory 16 Gbyte
• Disk Array 1 TB
• L2 1.5 Mbytes
• L3 128 Mbyte
• Memory 2 GB per processor

IBM POWER4 p Series
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INAF Osservatorio Astrofisico di Catania
FLY http//www.ct.astro.it/fly/

• High Performance Code for MPP/SMP architecture
  using one-side communication paradigm SHMEM -
  LAPI
• Based on the Barnes- Hut Algorithm
• It runs on Cray-T3E System, SGI ORIGIN, and on
  IBM SP.
• The code runs simulations and requires 250 MB
  Ram for 1 million of particles
• The code structure can be sub-divided in two
  segments
• - Tree Formation (oct-tree decomposition)
• - Force Computation

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INAF Osservatorio Astrofisico di Catania
AstroMD Main built-in tools

• I/O data Formats Binary native, ASCII, TIPSY
  compliant
• Randomizer
• Structure detection
• Structure morphology
• Correlation Function
• Power Spectrum
• Group finder

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INAF Osservatorio Astrofisico di Catania
Colours are selected by a lookup table. Users
can choose the parameter to be visualized
Tipsy Reader Functionalities selection of range
by a cursor, colour dialog widget, etc..
Tipsy Reader loads Tipsy data both in Binary and
ASCII Format. Users do not need to convert input
Files to Tipsy natural format
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INAF Osservatorio Astrofisico di Catania
RANDOMIZER
Select a random-sample of the displayed points,
where the user can apply the analysis
tools. Sub-sample can be saved in binary and
ASCII files
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INAF Osservatorio Astrofisico di Catania
Structure detection and Morphological analysis
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INAF Osservatorio Astrofisico di Catania
Mathematical basis of Minkowski functionals
Minkowski functionals give us information about
geometry, mean curvature and Euler characteristic
of a cosmological sample.

• The first Minkowski functional F1(r) represents
  normalized surface of covering
• The second Minkowski functional F2(r) represents
  normalized mean curvature

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INAF Osservatorio Astrofisico di Catania
The third functional F3(r) represents the Euler
characteristic c of the covering. It is the most
important for the topological studies
considering the factor c
Ncontours - N tunnels positive values
characterize structures having a little amount of
tunnels, having principally a convex
structure Negative values indicate high
tunneling, and so characterize spongy-like
structures.
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INAF Osservatorio Astrofisico di Catania
Two-point correlation function
Several estimators exist to compute the
correlation function. We have limited our choice
to Peebles Hausers and to Hamiltons.
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INAF Osservatorio Astrofisico di Catania
Power Spectrum
The Power Spectrum of the matter distribution is
a quadratic statistic of the spatial clustering
The quantity r(k) is used to to compute the Power
Spectrum, where r(k) is the FFT of the mass
density, and K is the wavenumber.
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INAF Osservatorio Astrofisico di Catania
FOF friend-of-friend
The most common group finding algorithm is
known as friend-of-friend .It was first used
by Huchra and Geller (1982) and involves
searching around each sample galaxy for
companions close as for distance and velocity.
These companions are then searched for their
companions, and so on until no other companion is
found.
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INAF Osservatorio Astrofisico di Catania
Other funds for related projects to Cosmo.Lab

• CNAA projects ? 38.200 Euros

CNAA funds two projects with the main aim to
support specialist formation in the field of the
scientific visualization, mainly devoted for
young post-graduates, and to contribute to the
AstroMD dissemination. INAF Catania is
responsible for these two projects
Involved institutions INAF - Catania, INAF -
Milan, Department of Physics of Trieste and
University la Sapienza of Rome
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INAF Osservatorio Astrofisico di Catania

• INAF - Cineca Agreement (5000.000 Euros)

Enabling Technologies for HPC and Scientific
Visualization in Astrophysics
The INAF Cineca is the follow-up of a long term
collaboration between CINECA and the world of
Astrophysics. In the present agreement about
300.000 CPU hours each year are available to
astrophysicists. Some aspects of this agreement
regard also the Scientific Visualization related
to the simulations performed with the Cineca HPC
systems
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INAF Osservatorio Astrofisico di Catania

• Italian Ministry Special Funds
• EU Structural Funds for Objective 1 areas
  (1700.000 Euros)

HPC and Scientific Visualization

• This project has the following main aims
• Upgrade of the HPC local resources of the INAF
  OACT (a new IBM-SP system)
• Post-graduate formation in the field of HPC and
  Scientific Visualization
• Results Dissemination

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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Group of Interest
CORE Group Italian Participants to the CNAA
projects Roberto Capuzzo Dolcetta - University
La Sapienza of Rome Paolo Miocchi - University
La Sapienza of Rome Paola Di Matteo -
University La Sapienza of Rome Fabio
Governato INAF - Astronomical Observatory of
Milan Stefano Borgani University of
Trieste Alessio Romeo University of Catania
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Group of Interest
Extended Group Italian Participants to the INAF
CINECA Agreement and other institutions Lauro
Moscardini - University of PadovaGiuseppe Tormen
- University of PadovaGianluigi Bodo -
University of TorinoLuca Tornatore - Dep. of
Astronomy TrieteStefano Borgani Dep. of
Astronomy TriesteMartin Goetz - Theoretical
Astrophysics Center, CopenhagenGiuseppe Gavazzi
Univeristy of MilanPaola Parma - IRA
BolognaLuigina Feretti - IRA BolognaAlessandra
Zanichelli - IRA BolognaPasquale Londrillo -
University of BolognaAntonella Maselli -
Astronomical Observatory of ArcetriChiara
Mastropietro - Zurich UniversityMarco Montuori -
INFM Rome
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Group of Interest
CORE Group main tasks To participate in the
CNAA project set-up meeting of AstroMD and in the
prototype development To discuss and address
the development of the WP4 of Cosmo.Lab
project The AstroMD tools is a visualization
tool but also an on-the-fly analysis tools The
core group has established the basic analysis
tools for the WP4 in the framework of the
Cosmo.Lab project FoF Correlation
Function Power Spectrum Minkowski
Functionals Data Parsing Scalar Fields
Calculation (e.g. Entropy) 2-D Projection of
the density field Velocity dispersion Gravitat
ional lensing
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Group of Interest
Extended Group main tasks To participate in
the First joined User Group meeting ESTEDI -
Cosmo.Lab (Bologna June 3rd 2002) To discuss
and give suggestions and impressions for the
future development of AstroMD An AstroMD demo
session was given by the Cosmo.Lab groups An
interactive session with AstroMD was operated by
the participants of the interest group A
questionnaire has been filled by each
participant, that gives useful suggestions for
the future development of AstroMD (document) A
Beta version of the AstroMD tools was given to
each participant
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Group of Interest
Future Core Group Will participate during the
last phase of the project, in the evaluation of
the final product with technical considerations
and with the discussion of the policy diffusion
of the AstroMD tool Will contribute to future
developments and integrations of AstroMD with new
technologies like grid applications Extended
Group A second meeting will be done in Bologna
to evaluate the impact of the final product on
the Scientific Community, before the last public
release of AstroMD The final version will be
distributed to all the users of this group of
interest
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Testing and Validation

• The Test and Validation phase has the following
  main goals
• Integration of all functionalities implemented
  in the WP 4-7
• AstroMD test using data coming from numerical
  simulations and from observational catalogues
• Usefulness of the Virtual Reality

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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Testing and Validation
Integration of all functionalities implemented
in the WP 4-7

• A new design of AstroMD was decided and approved
  by all the participants to allow a fast and a
  simple integration of all tools, during the
  development phase
• A new GUI was designed using the OO language
• incr TCL.
• ? The CVS of the project was implemented to allow
  all the developers to upload new versions of the
  code in a fast and secure way

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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Testing and Validation
AstroMD test using data coming from numerical
simulations and from observational catalogues
Planned activities ? Run of a set of LSS
simulations with different cosmological models,
and comparison of the AstroMD analysis tools with
classical methods ? Run analysis and
visualization of AGN simulations using AstroMD ?
A meeting of the Group of Interest will be done
to have useful suggestions in this activity and
for observational catalogues
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INAF Osservatorio Astrofisico di Catania
Cosmo.Lab Testing and Validation
Usefulness of the Virtual Reality
? This activity is planned at the end of this
phase and will be carried out with the Group of
Interest at the Cineca Virtual Theatre and with
the stereographical capability of AstroMD that
allows the users to have a 3-D real
visualization. ? The evaluation will be carried
out both for particle-based cosmological
simulations and for mesh-based AGN simulations