From LOFAR to LOFAR2.0: advancing cutting-edge science in the next decade
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From LOFAR to LOFAR2.0:
advancing cutting-edge
science in the next decade
René Vermeulen
Director International LOFAR Telescope
Radio2018 and annual GLOW meeting
25 October 2018
Jena
This presentation has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730562 [RadioNet]
LOFAR: KEY FACTS
Ø Array of 51 dipole antenna stations concentrated in NL and
distributed across Europe (sub-arcsec resolution)
Ø 10-250 MHz: 96 Low Band Antennas (LBA; 10-90 MHz);
48/96 High Band Antenna 4x4 Tiles (HBA; 110-250 MHz)
Ø On-station data processing includes (in)coherent adding &
(multiple) beam forming, cyclic data buffering & readout
Ø Central data processing includes correlation/imaging and
in(coherent) adding/beam forming modes
Ø Responsive telescope generation of and response to triggers
Ø Pathfinder: technology, data intensive astronomy (7 PB/yr)
LBA HBA Station multi-
beam
Selfcalibration
Direction- Ø Abell 2256
Ø 120-180 MHz
dependent Ø σ = 110 μJy, θ ~ 5”
calibration
e et al. 2017 for description and preliminary data release
Courtesy of R. van Weeren
LOFAR KEY SCIENCE
SURVEYS COSMIC
MAGNETISM
PROJECTS
SOLAR & SPACE WEATHER
COSMIC RAYS TRANSIENTS & PULSARS EPOCH OF REIONIZATION
Initial LOFAR design tailored to key science applications
LOFAR SCIENCE OUTPUT
EPOCH OF REIONIZATION
EPOCH OF REIONIZATION LOFAR strenths to
detect EoR signals:
Ø High sensitivity
Ø High (arcsed) (arcsec)
r(arcsec) resolution
Ø The LOFAR team has
published the current
world-leading upper
limit
Patil et al. 2017
SURVEYS: THE LOFAR TWO-METRE SKY SURVEY (LoTSS)
Ø High-redshift radio galaxies: formation
and evolution of massive galaxies, rich
clusters and massive black holes
Ø Galaxy clusters: origin and evolution of
magnetic fields and relativistic electrons
Ø Determining the cosmic star-formation
history of the Universe
See Shimwell et al. 2017 for description and preliminary data release
Ø serendipitous discoveries
Ø How? Produce high fidelity images of the
entire Northern sky with a resolution of
5" and sensitivity of 100μJy/beam at
most declinations.
Ø Will not be surpassed as a northern sky
survey for the foreseeable future
Shimwell et al. 2018 first data release
Gas in Galaxies & Clusters
PSZ1G139.61+24.20
Savini et al.
“The Toothbrush” Abell 1132
van Weeren et al. Wilber et al.DETAILED SCRUTINY OF AGN AND STAR-FORMATION
M82 starburst & SNR activity Jet astrophysics
Varenius+ 2015 4C 43.15
Morabito+ 2016
Stellar wind outflow Starburst-driven outflow
Arp 220 Arp 299
Varenius+ 2018 Ramírez-Olivenc+ 2018The Brightest SNR: Cassiopeia A
M. Arias et al.: Low-frequency radio absorption in Cassiopeia A Relativistic electrons: Arias et al. 2018
A&A 612, A110 (2018)
Fig. 2. Left: spectral index map made from fitting a power law to all the narrow-band LOFAR images. Each image had a 10σ lower cut. Right:
Fig. 1. Left: Cas A in the LOFAR LBA. The central frequency is 54 MHz, the beam size is 1000 , the noise is 10 mJy beam 1 , andsquare root of the diagonal element of the covariance matrix of the fit corresponding to α. Overlaid are the radio contours at 70 MHz.
the dynamic
range is 13 000. Right: Cas A in the VLA L-band. Continuum image from combining the spectral windows at 1378 and 1750 MHz. The resolution
00 00 1
is 14 ⇥ 8 with a position angle of 70 , and the noise is 17 mJy beam .
Continuum spectra
Atomic & molecular gas: Salas et al. 2018
Recombination linesCOSMIC MAGNETISM
Probing magnetic fields in intergalactic filaments: excess of 2.5
rad/m2 on 3.4 Mpc scales in Giant Radio Galaxy
Courtesy of S. O’ SullivanPULSARS
ØLOTAAS – LOFAR Tied Array All-Sky Survey - deepest
low frequency pulsars survey ever performed:
• Discover exotic pulsar systems to test gravity,
constrain the physics of dense matter, and
probe the pulsar emission mechanism
• Characterize the low-frequency transient radio
sky on sub-second timescales
• Almost completed!
• 85 pulsars discovered so far
• One of the most successful pulsars surveys in
the last decade
Ø Discovery of 3 MSPs with LOFAR, including the
fastest MSP in the Galactic field (PSRJ0952-0607)
Ø J0250+58: slowest PSR ever: 23.5 s period!
Courtesy of C. Bassa, V. Kondratiev and C. M. TanTRANSIENTS & VARIABLES
Broderick et al. 2018 Stewart et al. 2015
Ø W 50 morphology in excellent agreement with Ø Detection of first LOFAR transient event (LBA)
higher-frequency maps. 150-MHz integrated flux ~
210 Jy. Ø 400 h monitoring data of NCP (single LBA sub-band in
MSSS).
Ø Most complete detection of radio shell of SNR G
38.7-1.4. Ø ILT J225347+862146: ~20 Jy at 60 MHz. Estimated
time-scale of event ~4 min
Ø SS 433 marginal variability at 150 MHz; rise
corresponds to extended flaring activity at GHz Ø Flare star? (Scattered) FRB with unusually steep radio
frequencies. spectrum (α < -4.7)?TRANSIENTS
LOFAR Rapid
Response
Observations of GRB
180706A
Ø Observations started
within 5 minutes of the
GRB
Ø top: X-ray light curve of
the gamma-ray burst
(GRB) detected by Swift
Observatory. Red box:
timescale of the LOFAR
observations
Ø bottom: LOFAR light
Kuiack et al. (submitted) curve at the position of
the GRB at 4 different
Ø AARTFAAC: Amsterdam-ASTRON Radio Transients Facility And timescales
Analysis Center
Ø No emission was
Ø New AARTFAAC source catalogue at 60 MHz detected placing the
deepest limits on this to PRELIMINARY
date
Rowlinson, Gourdji et al. (in prep.)LOFAR4SW - Probing Space Weather: solar radio bursts
Plot: Hamish Reid, University of Glasgow, UK
LOFAR can image the Sun with a cadence down to 0.1s using interferometry (Right: Type III radio burst, Mann et al.,
2018) and/or localise sources of emission by rastering the Sun and corona with ~200 “tied-array” beams using the full
core, each of which is a high-resolution dynamic spectrum (Left: J-burst, Reid & Kontar, 2017).
LOFAR4SW Richard FallowsHIG-ENERGY COSMIC RAYS
Ø Cosmic-ray events reconstruction
between 1016 – 1018 eV ->
acceleration and propagation
mechanisms
Ø Distribution of radio footprint
allows to reconstruct arrival
direction, energy and mass
composition of the primary
particle.
Ø Best and most precise CR
composition measurements to
date (Buitink et al., Nature,
2016).
Ø Good reconstruction of
polarization direction
Courtesy of L. RossettoLIGHTNING STUDIES
Routine for mapping thunderstorm and
lightning events:
Ø reconstruction of the on-sky position of the
electric discharge
Ø mapping the electric fields within clouds
during thunderstorms, and characterizing
B. Hare et al. Journal of Geophysical Research (2018) 123 their influence on cosmic-rays radio emission
T.N.G. Trinh et al. Submitted to Journal of Geophysical Research (2018)
Courtesy of L. RossettoFrom LOFAR to LOFAR2.0:
advancing cutting-edge
science in the next decade
René Vermeulen
Director International LOFAR Telescope
Radio2018 and annual GLOW meeting
25 October 2018
Jena
This presentation has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730562 [RadioNet]LOFAR2.0: cutting-edge science for the next decade
What is LOFAR2.0?
•Anchor a state-of-the-art, unique, highly productive
telescope from 2020-2030
• A staged expansion of the scientific and technical
capabilities of LOFAR
• A path to SKA2-Low (like LOFAR was for SKA1-Low)
+ Latvia!
LOFAR 2.0LOFAR2.0: cutting-edge science for the next decade
• Leverage existing investments:
- hardware (stations, networks, data centres)
- algoritms, software, pipelines
- community’s collected brainpower
• Remain unique and scientifically impactful (in SKA era):
- lowest frequencies
- highest resolution
- versatility
• Evolution: continuous community support & productivity
• Financially, technically feasible on a 3-10 year timescale
LOFAR 2.0Compared to SKA-Low Phase 1
LOFAR à LOFAR2.0
Reaches to 2x lower frequencies
>10x higher resolution
SKA-Low Phase 1
Reaches to 2x higher frequencies
>10x greater collecting areaLOFAR2.0: cutting-edge science for the next decade
Augment station electronics
- Use all LBAs + all HBA tiles simultaneously
Ionospheric calibration (with single clock)
Sensitivity
Broad-band transient science
- Improve RFI robustness/linearity
- Extend on-station data handling
New generation LBA dipoles
- Performance atLOFAR2.0: cutting-edge science for the next decade Additional antennas/stations Science-driven (& costly): - Sensitivity - Imaging fidelity (1, 10, 100, 1000+ km baselines) - Dedicated programmes (Space Weather) Additional HBA beams - Dedicated programmes (Space Weather) - Transient science - Efficiency multiplier Integration of NenuFAR - Ultimate LBA sensitivity at high resolution
LOFAR2.0 Stage 1: DUPLLO
Digital Upgrade for Premier LOFAR Low-band Observing
3.5 M€ funding obtained from NWO
design; upgrade NL stations
All ILT partners intending to join
Reveal what is invisible to
the high-band antennasDUPLLO All-Sky Survey
The Moon
(for comparison)
All-sky map that is unique for the next 20 years.
Provides a monumental legacy data set for
the astronomical community.Parameter space
The challenge
The challenge
The challenge
Scientifically limited Rich in science
High-Band
Breakthrough
techniques
No ionospheric correction Ionosphere well modeledThe challenge
Scientifically limited Rich in science
High-Band
Breakthrough
techniques
No ionospheric correction Ionosphere well modeled
Low-
Band
DUPLLO T he
l
Go aThe challenge
Scientifically limited Rich in science
High-Band
Breakthrough
techniques
No ionospheric correction Ionosphere well modeled
Low-
Band
DUPLLO T he
l
Go a
2xThe challenge
Scientifically limited Rich in science
High-Band
Breakthrough
techniques
No ionospheric correction Ionosphere well modeled
Low-
Band
DUPLLO T he
l
Go a
Precision
2x clockThe challenge
Scientifically limited Rich in science
High-Band
Breakthrough
techniques
No ionospheric correction Transfer Ionosphere well modeled
Information
Low-
Band
DUPLLO T he
l
Go a
Precision
2x clockProof of concept Low-band
High-band
Shown that low-band and high-band
ionosphere track each other
Shown that we can derive an
ionospheric phase screen from high-
band data
c e nt
R e r o ug h!
a k th
B r eDUPLLO Innovation
Scientifically limited Rich in science
- =
The stage is set…• When do the first stars start to
shine?
DUPLLO • How do supermassive black holes
Science and galaxy clusters shape the
Universe?
Goals
• What is the habitability around low-
mass stars and can we directly
detect exoplanets?Exoplanets, stars, and
habitability
• Magnetically active stars (M-
dwarfs) irradiating their
nearby planets
• Directly detect exoplanets (cf.
Io-Jupiter interaction)
• Non-synchrotron emission
only visible at very low
frequenciesGalactic science in our
Milky Way
• Discover the 90% “missing”
supernova remnants
• Pulsar wind nebulae as
particle accelerators
• Probe interstellar medium
using RRLsNearby galaxies
• Look at the global properties
of galaxies in a spatially
resolved way
• See how the interstellar gas
absorbs energy
• Understand the cycles of star-
formationActive galactic nuclei
• Feedback of energy that
regulates star formation
• Study the radio jets that
probe the energetics
• “Fossil” emission gives the
history of activity levelGalaxy clusters
• Cluster mergers are most
energetic events since the Big
Bang
• Radio haloes and relics trace
energetics and history of
merger
• Understand structure
formation in UniverseHigh-redshift Universe
• Discover high-redshift (z > 2)
radio galaxies
• Large sample to study galaxy
formation and evolution
• Probe EOR with >100 high-
redshift radio galaxies at z > 6Transients
• Compare 2-epoch all-sky
coverage
• Coherent emitters (compact
objects)
• Gravitational wave
counterpartsPulsars
• Ultra-steep spectrum point
sources in imaging surveys
• Find super-fast- or super-
slow-spinning neutron stars
• Constrain neutron star
equation of stateCosmic rays
• Most energetic particles in the
Universe, but their origin is
still unclear
• What sources, and what
acceleration mechanism(s)
• LOFAR can study the
transition from Galactic to
extragalactic sourcesEarth lightning
• Buffer boards can also
capture lightning strikes
• Lightning formation and
propagation still not well
understood
• Much higher precision
imaging of where lightning is
formingEarth ionosphere
• Calibration will give insight
into the structure and
dynamics of the ionosphere
• Detect 2nd and 3rd order
effects
• Model the scattering
conditions giving rise to
scintillationSun & space weather
• Solar flares and coronal mass
ejections create space
weather
• Early detection of these
bursts in radio
• This space weather can
disrupt artificial satellites and
the Earth’s magnetosphereLOFAR4SW: A Comprehensive Space Weather Observatory
LOFAR4SW Richard FallowsLOFAR - Probing Space Weather: solar radio bursts, solar
wind, magnetic field, ionosphere
Interplanetary Scintillation of compact radio
magnetic field sources used to probe solar
wind velocity and density.
m Multiple stations enable more-
n fro accurate cross-correlation
tio
R ota rce analysis.
y
r a da d sou
Fa arise
l
po
Ionospheric Faraday rotation of polarised
scintillation signal, from pulsars or
n Solar wind density Galactic foreground, offers
l atio and velocity prospect of interplanetary
il
c int e magnetic field measurement.
ary S ourc
t s
lane act
p
erp om
Int m c
fro
Cross-correlation of Variation in amount
time series -> of scintillation ->
velocity density
LOFAR4SW Richard FallowsSerendipity
• Sky never before probed at
such low frequencies, with
such high sensitivity and
angular resolution
• Other types of non-
synchrotron emittersCosmic magnetism Supermassive black holes Early Universe
Supernovae Galaxy clusters
Sun
Pulsars Gravitational wave events
Solar System Planets
Meteors
Nearby galaxies
Cosmic rays
Ionosphere
Interstellar medium
Lightning Space weather
“extraordinarily broad
scientific program” Ref. 2From LOFAR to LOFAR2.0:
advancing cutting-edge
science in the next decade
René Vermeulen
Director International LOFAR Telescope
Radio2018 and annual GLOW meeting
25 October 2018
Jena
This presentation has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730562 [RadioNet]You can also read
