LOFAR-UK
A proposal to STFC PPRP
PI Professor Rob Fender (Southampton)
On behalf of the following consortium:
Liverpool John Moores University, The Open
University, The Universities of Cambridge, Cardiff,
Durham, Edinburgh, Glasgow, Hertfordshire,
Manchester, Oxford, Portsmouth, Southampton,
Aberystwyth, University College London, The
Rutherford-Appleton laboratory
+ Universities of Kent and Sussex, QMU and ATC
contingent on SUPA2 and SEPNET funding
A ‘next generation’ radio telescope under
construction in Europe, operating in 30—240 MHz
frequency range. Thousands of small dipoles (no
dishes) connected by high-speed internet to a
central processing facility.
Orders of magnitude improvement in sensitivity and
survey speed compared to previous observation at
these frequencies. Extremely diverse science case
and user community.
Pathfinder for the low-frequency component of the
Square Kilometre Array (SKA), a key component of
the RCUK large facilities roadmap.
LOFAR science case
LOFAR Key Science Projects
• Epoch of Reionisation (EoR)
• Deep extragalactic surveys
• Radio transients and Pulsars
• Cosmic rays and particle astrophysics
• Solar physics
• Cosmic Magnetism
Guaranteed time will be allocated to these KSPs for the
first ~5 years of LOFAR operations, with a steadily
increasing fraction of open time.
The Epoch of Reionisation
Reionisation of the
Universe, following
the ‘dark ages’,
occurred 6 < z < 12
This redshifts the
21cm HI line to the
LOFAR frequency
range, allowing
mapping of EoR
signal
Key issue is removal
of radio foreground
Deep extragalactic surveys
LOFAR will detect 108 extragalactic radio sources (primarily
starburst galaxies)  fantastic resource for cosmology
Requires international baselines to fulfil its potential
Radio Transients and Pulsars
LOFAR will scan a large fraction of the entire sky ~daily,
providing a Radio Sky Monitor for the first time.
Combined with
targeted surveys, we
will study
Accreting black holes
/ neutron stars
Pulsars
Extrasolar planets
‘LIGO events’ + … ?
Collaboration with LT
already established
Cosmic rays / particle astrophysics
CR produce radio
pulse
High-energy particles (e.g.
neutrinos) can produce radio
burst by interacting with moon
Cosmic magnetism
LOFAR polarisation surveys will allow
unprecedented mapping of large-scale magnetic
structures within our galaxy and other galaxies
This KSP has the practical
task of making LOFAR
polarisation calibration work
Solar physics
LOFAR is a fantastic tool for monitoring the Sun as well
as the solar wind / ejections and their propagation out
through the inner solar system
Stand-alone science
LOFAR stations can be used as stand-alone
observatories for monitoring variable sources e.g.
pulsars, solar activity, radio transients
The LOFAR-UK white paper
On Feb 8 we published the LOFAR-UK white paper on
astro-ph (see also LOFAR-UK website www.lofar-uk.org)
LOFAR-UK White Paper: A
Science case for UK involvement
in LOFAR
astro-ph/arXiv:0802.1186
The need for long baselines
LOFAR with panEuropean baselines –
of which LOFAR-UK
will be a key part – will
have ten times better
angular resolution
than the Dutch LOFAR
alone.
This dramatically improves LOFAR’s ability to make deep
extragalactic surveys due to the confusion limit
It also allows spatially resolved imaging of relativistic
jets, the Sun, galactic structure, clusters of galaxies etc.
LOFAR-UK are not limited to long-baseline only science!
LOFAR technical case
Low-band antennae (LBA)
30—80 MHz
Digital beamforming at
station level
Inbetween: FM radio band
High-band antennae (HBA)
120—240 MHz
Arranged in 5x5 HBA tiles
Analogue beamforming at tile
level
How LOFAR works in a
nutshell
Multiple beams
Correlation of
different stations
Single dipole
Station
+ beamforming
BlueGene
Latest LBA results
Three entire
hemisphere
images
Data
reduction /
analysis by
prototype of
final software
More than
400 sources
detected (c.f.
RXTE ASM)
HBA CS1 image
4 tiles + 12
individual HBAs
500m max baseline
The complete
LOFAR will have
x 500 collecting
area
x 6 bandwidth
x 2000 baseline
Observing
frequency
125—175 MHz
Cas A removed to
~1% level
0.5 Jy r.m.s.
Red squares
sources from 4C
radio catalogue
E(uropean)-LOFAR,
The SKA
and
LOFAR-UK
E-LOFAR
European
expansion is
well-funded
LOFAR-UK
1—4
LOFAR-NL
ASTRON
The Observatory
ARC + DMT
(with UK presence)
Universities
36—50
FLOW
1
SLOW
1
GLOW
4—7
Also Italy, Poland, Austria, Ukr.
(Fender PI on FP7 E-LOFAR proposal)
LOFAR as a SKA pathfinder
The Square Kilometre Array is one of just two astronomical
facilities in the RCUK large facilities roadmap
The SKA will have three
different antenna
systems sharing a
common infrastructure:
Low freq dipoles
Intermediate freq tiles
High freq dishes
LOFAR is the only fully-funded pathfinder for the Low
freq component of the SKA (cf MWA, LWA), and is the
only SKA pathfinder of any sort under construction in
Europe (cf ASKAP, MeerKAT)
LOFAR-UK
Formed in 2004
SUPA2
£600k raised in institutional
contributions, plus
donations of land at 4 sites
Edinburgh
Glasgow
Durham
LJMU
Manchester
Aberystwyth
O.U.
Cardiff
Cambridge
RAL
Oxford
SEPNET
Southampton
Hertfordshire
UCL/MSSL
Portsmouth
Very broad
support
extending beyond
the traditional
radio astronomy
institutes
LOFAR:UK Proposed station sites
Edinburgh: 850 km baseline
(U. Edinburgh land)
Using LOFAR-UK
funds already raised,
we have agreed first
station purchase with
ASTRON
(to be one of the three
stations in England –
Jodrell: 650 km baseline (U. Man land)
all of these have been
tested by ASTRON
technical team)
Lords Bridge: 450 km baseline (U. Camb land)
Data connections to
NL via SuperJanet 5
+commerical
Chilbolton: 600 km baseline (RAL/STFC land)
What is return for UK investment?
A disproportionately large amount of science
• Epoch of Reionisation (EoR) Core team involvement
• Deep extragalactic surveys Major involvement / board level
• Radio transients / Pulsars
Overall leadership (2/3 board)
• Cosmic rays
Core team involvement
• Solar physics
Major involvement / board level
• Cosmic Magnetism
Core team involvement
PLUS vital training in preparation for development of SKA
This large level of involvement and leadership is based
upon delivery of 4 LOFAR-UK stations
Costs
The project has a base cost of £4M in two major subsystems
Including Working Allowance and Risk  £5M
Costs to be noted
• £600k already raised by consortium
• SEPNET: £2.15M astro bid, focussed on LOFAR
- £148k earmarked for hardware at Chilbolton
• SUPA2: £500k requested for LOFAR station at Edinburgh
NB1: we already have quote for all station costs except
HBAs, so risk on hardware costs is reduced
NB2: commitment to spend on further UK stations probably
needs to be with ASTRON by end 2008
£550k ‘in the bank’
SUPA2 contrib.
subtracted from I2
£267k
£972k
£200k
£469k
£386k
£862k
£407k
£998k
Management
Project manager to be
hired (at 50%)
Existing Management to
become the LOFAR-UK
board of University
members
STFC steering
committee to be
established
Meetings:
Management – monthly
Board – 6 monthly
Summary
LOFAR is a fully-funded ‘next generation’ radio
telescope and SKA pathfinder under construction in
The Netherlands
Expansion of the array across Europe is essential to
maximise its potential, and is already part-funded in
Germany, France, Sweden
For a base cost of ~£4M LOFAR-UK will make the UK a
major partner in LOFAR, providing access to
breakthrough science as well as training of people in
preparation for the SKA.