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

6283

catalogues

14

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