Astronomy & Astrophysics in India :
Emerging challenges in Data Flow
Tarun Souradeep,
IUCAA, Pune
NKN 2nd Annual Workshop IISc. , Bangalore
17th Oct 2013
Dynamic range of phenomena
10-35sec
Rapid Advance in Observational capability
Data driven science
Modeling phenomena with higher dynamic range
increasingly possible with growth in computation (Density (gm/cc): cosmic =10-29,Earth=10, Neutron star=1012)
Billion light years(lys)
Million lys
Thousand lys
Light days
Knowledge & Data flow in A&A
Theoretical Modeling
Numerical simulation Large dynamic range,
Diverse physics
Observations:
Data acquisition Large volume, high sampling
rates, rapid response
Data Distribution Multiple analysis centers,
Public , large distributed, global
science collaborations
Data Analysis Huge data, v multi-parameter
Follow up
Numerical Simulations in Astrophysics
Examples of simulations : Large scale structure of the Universe
Formation & interaction of galaxies
Formation of stars and solar systems
Complex structure of the Sun
Common features : Involve upto 109 or more “particles”
Complex interactions between particles: gravity, magneto-hydrodynamics etc
Long time-scale evolution, many steps
Large scale Universe : Complex
web of cold dark matter
Collision of 2 gas clouds
leading to formation of stars
Galaxy formation & evolution
• Gravitational contraction/collapse/stellar dynamics
• Gas Dynamics - often supersonic, relativistic
• MHD, Poynting Flows
• Radiative Transfer
• Stellar structure and evolution
• Particle acceleration
• Merger of neutron stars/black holes
N-body simulation, Smoothed Particle Hydrodynamics
SPH, CFD
CFD+Maxwell
PDE solvers, Green’s Function, Monte Carlo
PIC, Monte Carlo
Astrophysics via large numerical simulation
Numerical Relativity
PDE, Nuclear Chemistry, Thermodynamics
Ongoing HPC-based Astronomy Research
• IUCAA, Pune: MHD, Dynamos, N-body simulation, Structure formation,
Radiative transfer, Molecular chemistry, Dust scattering, CMB analysis,
Gravitational Waves, Pulsar search, Automated classification....
(IUCAA is linked to A&A research community in the University of India)
• TIFR, Mumbai: Stellar structure, Helioseismology, Gravitational lensing
• IIA, Bangalore: Radiative transfer, MHD, N-body simulation, Star Formation
• IISc, Bangalore: Plasma astrophysics, Galaxy dynamics, Hydrodynamics
• HRI, Allahabad: Cosmological simulations, Accretion hydrodynamics
• IISER, Mohali: N-body simulation, Structure formation
• Delhi University: Solar MHD, Gravitational Waves
• SNBNCBS, Kolkata: Accretion flows, Molecular chemistry
• NCRA, Pune: Real-time radio interferometry, Pulsar search & timing
•
• +++
Plenitude of Observations
Planck CMB sky map
Tarun Souradeep 9
Planck: 12 million pixels of temperature/polarization
(COBE detection: 4000 pixels)
Measurements of the
Cosmic Microwave Background
30 GHz 44 GHz 70 GHz
100 GHz 143 GHz 217 GHz
353 GHz 545 GHz 857 GHz
CMB Maps at Planck Frequencies
Planck Early Release 2011 Credit: ESA, HFI & LFI consortia
SZ clusters from Planck
Tarun Souradeep 11
Large Observational data sets
8000 deg2
287 million objects
1.3 million spectra
10 TB imaging data
2 TB catalogue data
Sloan Digital Sky Survey
13
470,992,970 point sources,
1,647,599 extended source
Large surveys
Time Domain Astronomy
Real-time search in and characterization of 4-D data arrays
position (x,y), colour (wavelength), time
Large surveys are in the offing at many places across the world
including India. Indian interest will include the processing of data
from local as well as some of the international facilities
Most of the computation will be for automatic detection,
characterization and classification of transient events, on which
the decision of follow-up operations will be based
Need both large network bandwidth and high compute power
Catalina Real-Time Transients Survey CSS090429:135125-075714
Flare star CSS090429:101546+033311
Dwarf Nova
CSS090426:074240+544425
Blazar 2EG J0744+5438
Vastly different physical phenomena, and yet they look the same
!Which ones are the most interesting and worthy of follow-up?
CRITICAL: Rapid, automated transient classification & distribution
International Virtual Observatory Alliance
Imminent transient Data deluge
Forthcoming on a time scale ~ 1 - 5 years: ~ 1 TB / night, ~104 transients / night (PanSTARRS, Skymapper, VISTA, VST…)
Forthcoming in ~ 8 - 10 years: LSST, ~ 30 TB / night, ~ 105 - 106 transients / night
Observational follow-up needs:
Rapid photometric/positional monitoring
Rapid spectroscopy
Information/computation infrastructure
A major,
qualitative
change!
• Now: data streams of ~ 0.1 TB / night, ~ 10 - 102 transients / night (CRTS, PQ, PTF, various SN surveys, asteroid surveys)
Transient classification technologies are essential
Mega-Science ventures
in
Indian A&A (upcoming & advanced proposals)
20
ASTROSAT
FIVE astronomy payloads for
simultaneous multi-band observations:
1. 2x 40-cm Ultraviolet Imaging
Telescopes (UVIT)
1. 3 Large Area Xenon
2. Proportional Counters (LAXPC)
3. A Soft X-ray Telescope (SXT)
4. A Cadmium-Zinc-Telluride
5. coded-mask imager (CZTI)
6. A Scanning Sky Monitor (SSM)
7. consisting of three one-dimensional
8. position-sensitive proportional
9. counters with coded masks.
Thirty Meter Telescope
Caltech
University of California
Canada
Japan
China
India (TMT-India proposal)
30m equivalent
primary mirror, 492 segments, 1.4m each,
FOV 20 arcmin, 0.31 to
28 micron, Angular
resolution with AO ~7 mas
21
Square-kilometer array (SKA) Proposed/Ongoing Indian participation
• Next big step in Radio Astronomy (an international telescope)
• Total collecting area of 1 million sq. meters (about 30 times the GMRT) !
• Will be spread over a much larger area : ~ thousand km !! (contintental size)
LIGO-India proposal GW observatory on Indian soil
4km arm length
Laser interferometer
A Century long Wait
• Einstein’s Gravitation (1916- ): Beauty : symmetry in fundamental physics –mother of gauge theories
& precision : matches all experimental tests till date to high precision
Gravitational Waves -- travelling space-time ripples
are a fundamental prediction
• Existence of GW inferred beyond doubt (Nobel Prize 1993)
• Feeble effect of GW on a Detector strong sources
GW Hertz experiment ruled out.
Only astrophysical systems involving huge masses and accelerating very strongly are potential detectable sources of GW signals.
GW Astronomy link
Astrophysical systems are sources of copious GW emission:
•GW emission efficiency (10% of mass for BH mergers) >>
EM radiation via Nuclear fusion (0.05% of mass)
Energy/mass emitted in GW from binary >> EM radiation in the lifetime
• Universe is buzzing with GW signals from cores of astrophysical
events Bursts (SN, GRB), mergers, accretion, stellar cannibalism ,…
• Extremely Weak interaction, hence, has been difficult to detect directly
But also implies GW carry unscreened & uncontaminated signals
96% universe does not
emit Electromagnetic signal!
Global Network of Adv. GW Observatories
LIGO-LLO: 4km
LIGO-LHO: 2km+ 4km GEO: 0.6km VIRGO: 3km
KAGRA 3 km (2017)
Network 1. Detection confidence 2. Duty cycle 3. Source direction 4. Polarization info.
LIGO-India
Time delays in milliseconds
India provides almost largest
possible baselines. (Antipodal baseline 42ms)
LIGO-India: … the opportunity Science Gain from Strategic Geographical Relocation
Source localization error Courtesy: S. Fairhurst
Launch of
Gravitational wave
Astronomy
Highly Multi-disciplinary
Astro++
Data from Gravitational wave experiments
Data comprised of Gravitational wave channel
(ASQ)
Environmental monitors
Internal engineering monitors
Multiple data products
beyond raw data
Reduced data sets
Level 1: gravitational wave
and environmental channels
Level 3: only gravitational
wave data.
Different sampling rates
IFO
En
v C
H
He
alth
1TB of raw data per day!
GW Data volume
Time series data sampled at 16Hz - 16kHz
Thousands of monitoring channels
“science channels”: ~1% of total data
per detector: 2B x 16kHz = 32kBps = ~1TB/year
Advanced LIGO data volume:
~1petabyte / year
Conflicting Requirements: • Low ‘seismicity’ (ground noise PSD)
• Low human generated noise, …..
• Air connectivity, road connectivity, data connectivity,… • Proximity to Academic institutions, labs, industry preferred, …
LIGO-India Site search
High data connectivity required
from a LIGO-India site at
relatively remote, underdeveloped
region in India.
Role of GW data centre Tier-2 data & compute centre for archival of GW data and analysis
Bring together GW scientists & data-analysts within the Indian science community.
Puts India on the global map for international LIGO Science Collab. wide facility.
Large University sector participation via IUCAA
• Tier2 like GWDA centre: ~200 Tf peak capability [~ 2014] Network: gigabit+ backbone, NKN, Few Gigabit dedicated link to LIGO Caltech
• Currently prototype data centre:
IUCAA data centre: (Jan 2013) 30 Tf , 600 Tb [94 nodes : 2 x 8-core Intel Xeon Sandybridge, 128 GB RAM/node, Infiniband interconnect]
• 10Tf for GW: Required set up tried out, 0.5-0.8 Gbps data transfer
All infrastructure (for expansion to ~300 Tf ) in place before leaving IUCAA.
[total investment ~ 2 M USD]
-
GW Data Centre @ IUCAA
Multi-messenger astronomy
Joint analysis with other observatories
for confident detection
studying physics of the emitting system
testing general relativity (speed of GW)
Quickly send triggers to other facilities
Publish triggers in databases (VOEvents format)
Demonstrated with a number of facilities
How does one transport increasingly large
astronomical data ?
Thank you !!!
Modelling
Star
Formation
using SPH
35 million
SPH particles.
6 million
core-hours
LIGO-India mega-science project: Salient points
On Indian Soil with International Cooperation (no competition)
Involvement at the threshold of a major science discovery!!!
AdvLIGO-USA precedes LIGO-India by ~3 years. Staggered time-line dual advantage.
Indian experimenters would participate in Adv-LIGO-USA
Significant US expertise will pave way for faster execution of LIGO-India
US hardware contribution ready : no uncertainty in timeline
Adv.LIGO is the Largest NSF funded project in USA
LIGO-India by NSF positive reviews , NSB approval for NSF to proceed as it deems best.
Expenditure entirely in Indian labs & Industry.
Very significant Industrial capability upgrade. Indian DAE labs & Industry assessed to be in position to carry out phase-I of LIGO-India. (Senior LIGO team visited Indian labs & facilities in Aug ,Oct, Dec 2011, Feb 2012]
Well defined training plan Generate large number (~100) of highly trained HRD in areas of wide application in S &T.
Major data analysis centre for the entire LIGO network. Huge
opportunity for Indian University participation.
National Knowledge Network GW data centre will need a high
bandwidth backbone connection
for data replication from Tier-1
centres at LIGO sites in US,
India, GW detectors in Europe
Japan,
As well as for users to use the
facility from their parent
institutions.
NKN can potentially provide this
facility between IndIGO member
institutions.
International connections, EU-
India Grid