The Jansky Very Large Array
• Rick Perley
Atacama Large Millimeter/submillimeter Array
Expanded Very Large Array
Robert C. Byrd Green Bank Telescope
Very Long Baseline Array
EVLA
The Very Large Array -- Overview
• The Very Large Array is a 27-element, reconfigurable interferometer array,
located in west-central New Mexico, USA. (lat = 34.1, long = 107.6).
• High elevation (2100 m), desert climate (20 cm precip), means good
observing conditions most of the year.
• There are four major configurations, offering a range of over 300 in imaging
resolution.
– e.g. 1.5” – 400” at l=21cm
• The original VLA,
commissioned in 1980, has
now been upgraded.
• The new instrument – the
Jansky Very Large Array, has
hugely improved capabilities.
ASIAA Workshop on the Jansky Very Large Array
2
EVLA Project Overview
EVLA
• The EVLA Project is a major expansion of the Very Large
Array.
– The upgraded telescope is now called the Jansky Very Large Array.
• Fundamental goal of the project: At least one order-ofmagnitude improvement in all observational capabilities,
except spatial resolution.
• The project began in 2001, and will be completed early in
2013 – on budget and on schedule.
• Key aspect: A leveraged project, building on existing VLA
infrastructure.
– A sound strategy for these fiscally constrained times …
ASIAA Workshop on the Jansky Very Large Array
3
EVLA
Major Goals for the VLA’s Upgrade
• Full frequency coverage from 1 to 50 GHz.
– Provided by 8 frequency bands with cryogenic receivers.
• Up to 8 GHz instantaneous bandwidth
– Provided by two independent dual-polarization frequency pairs, each of up to 4
GHz bandwidth per polarization.
– All digital design to maximize instrumental stability and repeatability.
• New correlator with 8 GHz/polarization capability
– Designed, funded, and constructed by our Canadian partners, HIA/DRAO
– Unprecedented flexibility in matching resources to science goals.
• <3 mJy/beam (1-s, 1-Hr) continuum sensitivity at most bands.
• <1 mJy/beam (1-s, 1-Hr, 1-km/sec) line sensitivity at most bands.
• Noise-limited, full-field imaging in all Stokes parameters for most
observational fields.
– Requires higher level of software for calibration, imaging, and deconvolution.
ASIAA Workshop on the Jansky Very Large Array
4
EVLA
Jansky VLA-VLA Capabilities Comparison
The upgraded VLA’s performance is vastly better than the VLA’s:
Parameter
VLA
EVLA
Factor
Current
10 mJy
1 mJy
10
2 mJy
0.1 GHz
8 GHz
80
8 GHz*
# of frequency channels at max. BW
16
16,384
1024
16384*
Maximum number of freq. channels
512
4,194,304
8192
131072
Coarsest frequency resolution
50 MHz
2 MHz
25
2 MHz
Finest frequency resolution
381 Hz
0.12 Hz
3180
15.3 Hz
2
64
32
64*
22%
100%
5
100%
Point Source Cont. Sensitivity (1s,12hr.)
Maximum BW in each polarization
# of full-polarization spectral windows
(Log) Frequency Coverage (1 – 50 GHz)
* New capabilities, now under testing, to be made available in Jan, 2013
5
EVLA
The EVLA is a ‘Leveraged Investment’
• The Project is making maximum
use of existing hardware and
infrastructure.
• The EVLA utilizes the VLA’s 25meter parabaloids.
– Off-axis Cassegrain optics.
– Change band by rotating
subreflector
• Disadvantages:
– Big and slow
– Not the best choice for fast
wide-field surveys
• Advantages:
– Paid for!
– Work well up to 50 GHz.
• Also retained:
– Configurations, buildings, basic
infrastructure, people.
Antenna 24 – the first EVLA antenna
outfitted with all eight feeds.
ASIAA Workshop on the Jansky Very Large Array
6
EVLA
Full Frequency Coverage with
Outstanding Performance
• There are eight feeds, tightly
packed around the secondary
focus feed ring.
Band
(GHz)
Feed
Heaters
Tsys/e
X
(best weather)
1-2
L
60 -- 80
2-4
S
55 -- 70
4-8
C
45 -- 60
8-12
X
40 -- 50
12-18
Ku
50 -- 60
18-26.5
K
70 -- 80
26.5-40
Ka
90 -- 130
40-50
Q
160 - 360
C
L
S
Ku
K
Ka
Q
7
VLA Sensitivity (rms in 1 Hour)
EVLA
• Achieved sensitivities
exceed project
requirements at all
frequencies above 8
GHz.
• Sensitivities below 8
GHz are at, or a little
below requirements.
• In most cases, the
reasons are
understood, and
modifications are
ongoing.
8
EVLA
EVLA Project Status (Sept 2012)
• Installation of new wideband receivers now complete at:
–
–
–
–
4 – 8 GHz (C-Band)
18 – 27 GHz (K-Band)
27 – 40 GHz (Ka-Band)
40 – 50 GHz (Q-Band)
• Installation of remaining four bands completed late-2012:
–
–
–
–
1 – 2 GHz (L-Band) 23 now, completed end of 2012.
2 – 4 GHz (S-Band) 25 now, completed Sept. 2012.
8 – 12 GHz (X-Band) 20 now, completed end of 2012.
12 – 18 GHz (Ku-Band) 23 now, completed end of 2012.
• In addition (but outside the Project), we are outfitting a new
wideband low-frequency receiver (paid for by NRL).
– Twelve systems now outfitted, the rest by early to mid 2013.
ASIAA Workshop on the Jansky Very Large Array
9
Full Bandwidth Capabilities
EVLA
• Each antenna has four 2-Gsamp/sec 8-bit samplers.
– Provides 2 GHz/polarization instantaneous BW, used for L, S, and lowband.
– These were installed early in the project, and work well.
• Each antenna also has eight 4-Gsamp/s, 3-bit, samplers.
– Provides 8 GHz/polarization instantaneous bandwidth.
– Used at high frequency bands for full frequency coverage.
– We are currently implementing the software and methodologies
needed to utilize this new capability.
– Full BW capability will be offered for astronomy, beginning Jan 2013.
– Some negative issues with this system: a 10 – 15% loss in sensitivity is
the most important.
ASIAA Workshop on the Jansky Very Large Array
10
The ‘WIDAR’ Correlator
EVLA
• The VLA’s new correlator was built to NRAO’s requirements
by the DRAO correlator group, located at the HIA facility
near Penticton, BC, Canada.
• This ‘WIDAR’ correlator was paid for by the Canadian
government, as part of a cooperative agreement between the
Canadian NRC and the U.S. NSF.
• Installation of WIDAR began January, 2010. It was turned on
for astronomy in early March, 2010.
• This extraordinarily flexible machine is now fully installed at
the VLA site, and is working magnificently.
• We are far from deploying all its capabilities – this is a lengthy
process, which is months to years away from completion.
ASIAA Workshop on the Jansky Very Large Array
11
EVLA
The ‘WIDAR’ Correlator
• Accepts four input ‘baseband’ pairs of up to 2 GHz BW each.
• Each input is digitally sub-divided into 16 spectral window pairs.
• Each of the 4*16 = 64 spectral window pairs can be considered as a separate
full-polarization ‘sub-correlator’, with 256 channels.
Four Active Baseband Pairs
Initial Quantization = 3 bits
Re-Quantization = 4 bits
4 Input
Baseband
Pairs:
3-bits @
4.096
Gsamp/sec
Sub-band
BBP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
R - 2 GHz
Frequency 1
1
Q1
L - 2 GHz
R - 2 GHz
Frequency 2
Frequency 3
2
L - 2 GHz
1 sub-band pair with
RQ = 4:
R - 2 GHz
256 channels for
1, 2, or 4 polarization products
Maximum SBW = 128 MHz
3
L - 2 GHz
R - 2 GHz
Frequency 4
4
Q2
Q3
Q4
L - 2 GHz
Quadrant
There are 64 independent sub-band pairs,
each with its own center frequency, bandwidth, and
polarization combination
12
WIDAR’s Special Modes
EVLA
• WIDAR is much more than a basic cross-multiplying correlator.
It is designed to enable:
– Each of the 64 spectral windows can be tuned to its own frequency, with
its own bandwidth and spectral resolution (from 2 MHz to .12 Hz)
– 100 msec dump times with all 16384 channels and full polarization – and
faster if spectral resolution is decreased. Fastest so far is 10 msec, for
two polarizations, 2048 channels, and 1024 MHz bandwidth.
– > 44 dB (and up to 58 dB) isolation between spectral windows. (To
prevent RFI leakage contamination)
– Up to 8 sub-arrays.
– Phased array capability for full bandwidth: – for pulsar and VLBI
applications. Two different subarrays can be simultaneously phased.
– Special pulsar modes: 2 banks of 1000 time bins, and 200 msec time
resolution (all spectral channels), or 15 msec (64 channels/sp.window)
– VLBI enabled
ASIAA Workshop on the Jansky Very Large Array
13
Ongoing VLA Developments
EVLA
• The EVLA Construction Project ends this year.
• At year’s end, (virtually) all of the construction items (correlator, receivers,
samplers, etc.) will be completed.
• However, many software elements, needed for the more obscure or
sophisticated observing modes, will be ongoing.
• Claire will be speaking on the currently available modes, and the ‘shared
risk’ observing programs.
• We strongly urge observers who wish to use the more sophisticated
observational modes to come to Socorro, and spend ‘quality time’ with us!
ASIAA Workshop on the Jansky Very Large Array
14
EVLA
EVLA Design Driven By Four Themes
Magnetic Universe
Obscured Universe
Measure the
strength and
topology of
the cosmic
magnetic field.
Sgr A*
Transient Universe
Image young
stars and
massive
black holes in
dust enshrouded
environments.
Evolving Universe
Follow the rapid
evolution of
energetic
phenomena.
CO at z=6.4
Study the
formation and
evolution of
stars, galaxies
and AGN.
ASIAA Workshop on the Jansky Very Large Array
15
Magnetic Universe Theme
EVLA
– Synchrotron emission from radio galaxies, quasars, SNR
•
•
Maps magnetic fields within sources
Provides age estimates of structure
– Faraday Rotation Studies
•
Plane of polarized emission is rotated by magneto-ionic medium,
give estimate of line-of-sight magnetic field strength and structure.
– Zeeman Splitting Studies
•
•
Spectral transitions split into hyperfine structure by magnetic field.
Allows direct measurement of magnetic fields in line-emitting
environments.
ASIAA Workshop on the Jansky Very Large Array
16
Hercules A
•
•
•
•
(Perley and Cotton, demo)
EVLA
z = 0.154, radio galaxy. D = 710 Mpc, 1arcsec = 3.4 Kpc.
4-9 GHz color-code spectro-intensity image (redder = older). 1 Kpc resn.
EVLA data: 1 through 9 GHz, all four configurations, 1Kpc resolution.
Shocks in western lobe indicate repeated ejection.
ASIAA Workshop on the Jansky Very Large Array
17
EVLA
Relics and Jets in Abell 2256 at l = 20cm
•
•
•
•
•
A merging rich cluster
of galaxies
z = .058, D = 270 Mpc.
1–2 GHz, 20-arcmin on
a side (1.6 Mpc)
Studies of the complex
interactions between
galaxies, AGN feedback,
ICM, magnetic fields,
and dark matter
content of clusters
Role of radio galaxies
and relics in cluster
evolution?
Owen, Rudnick, Eilek, Rau, Bhatnagar, Kogan)
ASIAA Workshop on the Jansky Very Large Array
18
A2256 – Spectral Index - Intensity
EVLA
.
Wideband
data
permits
simultaneous
calculation of
spectral index.
Red = steep (old)
Blue = flat (young)
ASIAA Workshop on the Jansky Very Large Array
19
Faraday Rotation in A2256
EVLA
• Wide bandwidths and
narrow frequency
resolution will be a
boon to Faraday
rotation studies.
• New technique for
Faraday Rotation
Synthesis provides
information on B-fields
along line of sight, and
within emitting
volumes.
•
ASIAA Workshop on the Jansky Very Large Array
20
Zeeman Splitting Studies
EVLA
• Momjian and Sarma (2012): 44 GHz methanol maser from OMC-2.
• Stokes V signature gives zB = 18 Hz. (z = zeeman splitting factor –
unknown).
• Maser is 50%
stronger than in
2009, yet the
derived B-field
has remained
unchanged!
• Implications:
maser traces
large-scale field.
ASIAA Workshop on the Jansky Very Large Array
21
Evolving Universe Theme
EVLA
• New micro-Jy sensitivity allows deeper continuum imaging.
– Higher redshift continuum emission now within reach
– More objects, more types, more classes, more extremes
• Wide spectral coverage, and full frequency coverage, allows
studies of high-z molecular emission.
– Can do ‘double-blind searches’ – no prior knowledge of specific
transitions or specific sources.
– ‘Guaranteed’ that there will be early galaxies, detectable in line
emission, within a few hours integration, in any Ka or Q band beam!
– Something of a ‘gold rush’ underway now.
ASIAA Workshop on the Jansky Very Large Array
22
EVLA
A Panchromatic view of galaxy formation
• Modern
astronomy
utilizes
multiple
instruments
• VLA, ALMA,
and JWST (and
others) are
synergistic.
100 Mo yr-1 (M82)
cm: Star formation,
AGN, synchrotron
(sub)mm Dust,
FSL, mol. gas
Near-IR: Stars,
ionized gas, AGN
ASIAA Workshop on the Jansky Very Large Array
23
EVLA
M82 – The Prototype Nearby Starbust Galaxy
Shown is a deep C-band VLA image, combining A and B configuration data.
Resolution is 0.35 arcseconds (5 pc at distance of M82).
Extreme nuclear starburst driving a superwind > 1Kpc above disk.
Visible are: SNR and some HII regions throughout star forming disk.
J. Marvel, Owen, Eilek
• Synchrotron radio
halo shows
filamentary structures
• Matches H-alpha and
Xray images.
• Inhomogenous
distribution of superstar clusters drives
multiple outflow
channels.
•
•
•
•
24
EVLA
The “Radio Era” to Study Galaxy Evolution
• Stars and star formation studied to z ~ 8, i.e. 500 Myr after Big Bang
• Major unknown is the distribution and evolution of the cold gas reservoir
• EVLA and ALMA are poised to unveil the fuel for galaxy assembly…
SED of galaxy
forming 100 Msun
yr-1 at z=5
EVLA
ALMA Cont.
ASIAA Workshop on the Jansky Very Large Array
25
Molecular gas in early main
sequence galaxies
•
•
•
•
•
Herschel has identified large samples of
gravitationally lensed, very dusty, FIR
luminous star forming galaxies, but optical
redshifts are difficult to obtain due to
obscuration
Wide bandwidth of VLA has become a
powerful tool to obtain redshifts, and
molecular gas properties
VLA has imaged the molecular gas in a set
of lower luminosity star forming galaxies at
z~2.5
Large, rotating disks are seen, containing
warm molecular gas
They also detect thermal Free Free emission
for the first time in distant galaxies, providing
the best measure to date of star formation
rates
ASIAA Workshop on the Jansky Very Large Array
EVLA
VLA spectra and images of a star
forming galaxy at z=2.5
(Thompson et al. 2012) 26
EVLA
An Old Mystery in the High z Universe
Hughes et al (1998)
• The strongest submm source in the
HDF lacks a counterpart or redshift.
• Known as HDF850.1, no
identification with any optical/IR
image was made for many years
following its discovery in 1998.
• Dunlop et al. (2002) proposed an
identification with deep imaging
done with Subaru.
• Estimated redshift: 4.1
HDF 850.1
ASIAA Workshop on the Jansky Very Large Array
27
EVLA
An Old Mystery in the High z Universe
• The brightest submm source in the
HDF lacks a counterpart or redshift
• Blind molecular line survey of HDF
with PdBI identifies redshift
• Confirmed with EVLA CO(2-1)
• HDF 850.1 is a rare ultraluminous
starburst galaxy:
Walter et al, Nature in press (2012)
– z=5.183 (further than predicted)
– In galaxy over-density at z=5.2
– 850 M/year, Mdyn=1011 M
• Still no optical/NIR counterpart
• Highlights the value of blind surveys
and future ALMA and EVLA synergy
HDF 850.1
ASIAA Workshop on the Jansky Very Large Array
28
A Molecule-Rich Protocluster
Foreground sBzK galaxy
CO 1-0
46 GHz Observations of GN20
EVLA
Frequency Span = 256 MHz; FoV = 60”
CARILLI ET AL. (2011)
z=1.5
CO 2-1 Spectroscopy
Imaging CO 2-1
z=4.055
CO 2-1, HST, sub-mm
z=4.05
1
z=4.056
48,550
48,750
48,650
Frequency [MHz]
Wide bandwidth=Large redshift range, e.g. a single EVLA pointing at
30 GHz surveys a region at z=3 of 700 x 700 Mpc with Δz~1 in
the CO (1-0) transition
ASIAA Workshop on the Jansky Very Large Array
29
EVLA
Exploring the Radio Sky at 1 uJy/beam
• The Balloon-borne instrument
ARCADE 2 measured a sky
brightness of 54 +/- 6 mK at 3.3
GHz.
• The known population of radio
sources can only provide ~10 mK.
• Support from Owen and Morrison
(2008) who saw flat normalized
source counts down to 17 uJy
• Is the excess ~45 mK real?
• If so, is it due to a new population?
• If so, will SKA key science be
limited by source confusion?
• Condon et al. have investigated this
with VLA’s new S-band system.
ASIAA Workshop on the Jansky Very Large Array
30
EVLA
Deeper Knowledge Through Confusion
• Confusion” is term given to
fluctuations caused by blends
of faint sources not resolved
by the point-source response
• Image brightness fluctuations
P(D) yield statistic “counts” of
sources
• Confusion-limited EVLA
images will be able to
constrain the population of
extragalactic sources as faint
as 1 microJy at 1 GHz .
• A 3 GHz project was recently
carried out by Condon et al.
(astro-ph/1207.2439)
•
•
•
•
The plot is clipped at 100 mJy/beam.
The rms noise is 1% of this peak
Every ‘bump’ in the map is real signal!
About 50 hours on-source integration,
with 21 antennas.
ASIAA Workshop on the Jansky Very Large Array
31
EVLA
Results – No excess to 1 mJy/beam!
• P(D) analysis shows number count heading downwards, as predicted by
models.
• No excess of faint sources visible.
• If the ARCADE
result is right, the
responsible
objects are much
weaker than 1mJy,
with high surface
density.
ASIAA Workshop on the Jansky Very Large Array
32
Transient Universe Theme
EVLA
• Searching for RRATs – pulsars with sporadic pulses.
• Solar flare science.
– Radio studies ongoing since late 1940s.
– Provides insight into particle acceleration and energy release.
– Important role in discovery of CMEs.
• Flare star science
• Brown Dwarfs
ASIAA Workshop on the Jansky Very Large Array
33
EVLA
Transient Science – RRATs at the VLA
• Law and Bower (UCB) have taken 16 minutes of VLA data with 10 ms time
resolution. This gives 90 GB data!
• Bispectrum analysis (Law & Bower, 2012) of raw data found a single pulse.
• Image of a single time interval, and its dispersion function shown below.
(Law et al., 2012)
ASIAA Workshop on the Jansky Very Large Array
34
EVLA
Solar Transient Science: Suprathermal
Electron Beams in the Solar Corona
• Shown here is a dynamic
spectrum, time to the right,
frequency vertical.
• Time resolution is 100 ms.
• Data taken at 1 – 2 GHz, in Nov
2011, during a modest flare.
• Vertical lines are Type III bursts.
• An image can be made for each
(frequency, time) pixel.
Chen et al. (2012)
ASIAA Workshop on the Jansky Very Large Array
35
EVLA
Suprathermal Electron Beams in the
Solar Corona
• Each color ‘dot’ shows centroid
position of radio burst, color coded
for frequency.
• Background is EUV image of the sun
at the same time.
• Emission at different frequencies
originates from different places in the
corona
• Progression plots the electron beam
trajectories, representing the topology
of the magnetic fields.
• Contours show HXR emission.
• Footprint HXR sources, hot EUV loop topology, and type III burst
trajectories show a consistent picture of flare energy release, particle
acceleration, and flare energy release.
ASIAA Workshop on the Jansky Very Large Array
36
EVLA
Sweeping Radio Burst Detected with the VLA
On Flare Star UV Ceti (Hallinan, 2012)
• On left: Solar dynamic spectrum of type III radio burst, and Langmuir
waves from Galileo spacecraft. Flare propagates upwards.
• On Right: VLA S and C-band spectra on flare star UV Ceti (only one
subarray, so one band at a time), show possibly similar structure, but
moving in downwards direction (type III dm). Is there a connection?
Dynamic Spectrum of Flare on UV Ceti
5.5
Stellar radio burst from UV Ceti
5
Solar Type II burst Nov 2005
(credit: Stephen White)
Frequency (GHz)
4.5
?
4
3.5 detected from UV Ceti
- A bright 100% circularly polarized radio burst was
3
- Drifts in time and frequency similar to solar type bursts
2.5
- The JVLA will open a new field of research on the2 study of stellar radio bursts
50
55
60
65
70
75
80
85
Time since MJD 55589 (minutes )
ASIAA Workshop on the Jansky Very Large Array
37
VLA: First results – 2MASS J0746+20
EVLA
• L Dwarf Star in solar neighborhood
• Shown are dynamic spectra, taken in C-band (2 x 1 GHz chunks)
• Period emission from a rotating auroral hotspot
Hallinan, 2012
- 2MASS J0746+20 -> L0+L1.5
- Period: 2.07 hours
- Magnetic field range: 1500 Gauss – 2800 Gauss
ASIAA Workshop on the Jansky Very Large Array
38
EVLA
Dynamic Imaging of 2MASS J0746+20
• 12.5 hours of data with 2 GHz bandwidth (4.3-5.3 & 6.9-7.9 GHz).
• RMS noise ~ 1.6 mJy/beam
ASIAA Workshop on the Jansky Very Large Array
39
Obscured Universe Theme
EVLA
• Cm-wavelength observations nearly unattenuated by dust.
• VLA can detect regions too optically thick for visible, IR, and
mm-wave instruments.
• Star-forming regions, protoplanetary disks, proto-stellar
objects, HII regions, and much more are likely targets for
high-resolution cm-wave studies with the VLA.
ASIAA Workshop on the Jansky Very Large Array
40
New K, Ka-band Observations of the
Galactic Center (Mills et al.)
EVLA
The Galactic Center: A Busy Neighborhood!
Area of interest: The ‘Sickle’
ASIAA Workshop on the Jansky Very Large Array
41
EVLA
The Region in Paschen a (IR, 1870 nm)
and 25 GHz (radio, 1.2 cm)
ASIAA Workshop on the Jansky Very Large Array
42
EVLA
36 GHz Methonal Masers – everywhere!
• Tracers of shocks. Abundant, even in apparently quiet clouds.
• Shown is methanol masers, ammonia (3,3), and continuum, all from VLA.
ASIAA Workshop on the Jansky Very Large Array
43
EVLA
Grain growth and sub-structure in
protoplanetary and protostellar disks
• Disks in deeply embedded protostars:
– Dust emission is optically-thick at ALMA’s submm wavelengths!
– Need cm wavelengths to:
• penetrate dusty envelopes to measure disk formation and growth
• determine kinematics of disks in dense regions (massive protostars and disks
around Class 0 low-mass protostars)
• Disks around pre-main sequence stars:
– To measure contribution from cm-sized dust grains use frequency dependence
of dust opacity, b (t  nb), at cm wavelengths
– Need high spatial resolution imaging to separate large t from b
• demonstrate growth of planetesimals
• determine grain size distributions
• Disk/jet interactions
– Assess contributions from free-free emission
– Imaging of ionized gas with resolution comparable to ALMA
ASIAA Workshop on the Jansky Very Large Array
44
EVLA
Bandwidth. A nice problem to have
ASIAA Workshop on the Jansky Very Large Array
45
EVLA
VLA demonstration science: IRC+10216
• IRC+10216 (CWLeonis) is a carbon star embedded in a thick dust envelope.
• Discovered by Becklin in 1969 in early IR survey.
• The expanding envelope (astrosphere) is a rich source of molecular
transitions
ASIAA Workshop on the Jansky Very Large Array
46
EVLA
VLA demonstration science: IRC+10216
• Spectroscopy and imaging of IRC+10216, using cyanoacetylene emission.
• HC3N(4-3) emission a 36.4 GHz tracing the expanding shell
• Similar movies for HC5N(9-8), HC7N(22-21), SiS(2-1), reveal chemical
structure of the envelope
SiS
HC3N
HC5N
HC7N
ASIAA Workshop on the Jansky Very Large Array
47
Summary Slide
EVLA
• The Jansky Very Large Array offers new capabilities, orders of magnitude
better than any other cm-wave system.
• Users are responding with large numbers of proposal, targeting the new
capabilities.
• Largest growth area – continuing a trend begun in VLA days – is in high
frequency science: thermal science, and early universe science.
• The best is yet to come!
ASIAA Workshop on the Jansky Very Large Array
48