Image credit: Seth Shostak
The LUNASKA project:searching for radio pulses fromultra-high-energy particles
impacting the Moon
Justin BrayClancy James
LUNASKA collaboration:Mark Aartsen, Jaime Alvarez-Muniz, Andrew Brown, Justin Bray,Ron Ekers, Clancy James, Rebecca McFadden, Chris Phillips,
Ray Protheroe, John Reynolds, Paul Roberts
Recent Ron students
I Clancy James
I Rebecca McFadden
I Laura Bonavera
I Rajan Chhetri
I Elizabeth Mahony
I Justin Bray
I Nipanjana Patra
I Joe Callingham
I . . .
Cosmic rays
Cosmic rays
Cosmic-ray arrival directions
Pierre Auger Collaboration 2007, Science, 318, 938
Neutrinos
Neutrinos
The Short Version
There could be cosmic rays and/orneutrinos at extremely high energies.
We would like to detect them.
Detect particle interactions in dense media . . .
“by means of suitable apparatus dropped on the moon”
Lunar Cherenkov emissionLunar Cherenkov emissionneutrino
photon
shower
Concept: Dagkesamanskii & Zheleznykh,Proc. International Cosmic RayConference, Adelaide, 1990
Figure: Ron
Lunatic logbook, 1995
1.2 GHz
1.7 GHz
+
trigger
datastorage
Dispersive delay:
τd = 0.012 ∆ν STEC ν−3
1.2 GHz
1.7 GHz
+
datastorage
Dispersive delay:
τd = 0.012 ∆ν STEC ν−3
Should be:
τd = 0.00268 ∆ν STEC ν−3
PIs: Ray Protheroe& Ron Ekers
Sciences. Life impact.
Postgraduate opportunity in Astrophysics
The Faculty of Sciences, University of Adelaide is offering a postgraduate scholarship for PhD study in Astrophysics. Top-up scholarships are also available. The new project, Lunar Ultra-high energy Neutrino Astrophysics using the SKA (LUNASKA), will be part of the design study for the international Square Kilometre Array of radio telescopes due for construction in 2010-2015. Project partners include collaborators at the Australia Telescope National Facility (ATNF) and Universities in the USA and Spain. For further information on PhD projects, visit the LUNASKA website at: www.physics.adelaide.edu.au/astrophysics/ If you have a good honours degree in physics, mathematics, engineering or computing you may be eligible to join this exciting new project
For conditions of award visit: http://www.adelaide.edu.au/graduatecentre/scholarships/postgrad/
For all other information contact: Faculty of Sciences Phone: (08) 8303 5673 Email [email protected]
LUNASKA group
Adelaide, 2008
Left to right:
I Rebecca McFadden
I Ron Ekers
I Ray Protheroe
I Clancy James
I Justin Bray
I Jaime Alvarez-Muniz
Missing:
I Chris Phillips
I Paul Roberts
Joined later:
I Mark Aartsen
I Andrew Brown
I John Reynolds
LUNASKA ATCA observations (2007–2008)
I Dedispersion implemented in hardware
I Need stable ionosphere
I Observer 10pm to 6am
Long night of observations:
I Midnight: Rebecca ceases to function
I 3am: Clancy ceases to function
I 5am: Ron wants to plan the observationstrategy for the next night . . .
Ron explains thededispersion filter(held by Rebecca) toJaime.
ATCA 2008: Clancy in charge of LUNASKA ATCA obs
I Targeting neutrinos from Cen A
I Point at the edge of the moon closest to Cen A
I Get pointing data from JPL ‘Horizons’
I But which lunar coordinate system does NASA use?
First night:
I Walk outside with ATCA binoculars.
I Look at the moon. Compare craters. Know where East/West are.
I Determine coordinate system; enter telescope pointing data.
Second night:
I Forget result from first night.
I Walk outside — the sky is completely overcast! What to do?
I Poster on ground floor of ATCA control building: photograph of
ATCA showing background mountains (East) and the moon.
Ron’s favourite plots from Clancy’s thesis
LUNASKA Parkes (2009–2010), ∼ 200 h
limbTsys∼55K
limbTsys∼55K
half-limbTsys∼140K
off-MoonTsys∼30K
I radial polarisation
I anti-coincidence filter
Completely different strategy.My first hayride!
Neutrinos, or RFI?
8.0 8.5 9.0 9.5 10.0Pulse height (sigma)
100
101
102
Puls
es p
er 0
.05-
sigm
a bi
n
Prompted followup ∼ 30 h joint Parkes-ATCA experiment.Which I then abandoned.
Neutrinos, or RFI?
8.0 8.5 9.0 9.5 10.0Pulse height (sigma)
100
101
102
Puls
es p
er 0
.05-
sigm
a bi
n
Prompted followup ∼ 30 h joint Parkes-ATCA experiment.
Which I then abandoned.
Neutrinos, or RFI?
8.0 8.5 9.0 9.5 10.0Pulse height (sigma)
100
101
102
Puls
es p
er 0
.05-
sigm
a bi
n
Prompted followup ∼ 30 h joint Parkes-ATCA experiment.Which I then abandoned.
Just RFI
6 7 8 9 10 11 12Peak amplitude (σ)
100
101
102
103
104
105
Even
ts p
er b
in
no cutscuts #1-2 (anticoincidence)
cuts #3-4 (width)cut #5 (proximity)
cut #6 (strict)
expected
Definite non-detection.
Other experiments: NuMoon WSRT
60 40 20 0 20 40 60
θ (′ )
0.01
0.10
1.00
B(θ)
primary beam
FWHM4.2′ each
2.8′ separation
60 40 20 0 20 40 60
I anti-coincidence filter
0
20
40
60
80
100
Sum
med
pow
er, S
detection threshold, S = 90
exclusion threshold, S = 20
0.14 µV/m/MHz< E <
0.17 µV/m/MHz
Other experiments: RESUN VLA
× 4antennabeams
× 4antennabeams
× 4antennabeams
I three sub-arrays
I real-time coincidence triggerI four channels per antenna,
coherently combined
How did we do?
Detection thresholds
LUNASKA Parkes: 0.0053 µV/m/MHzLUNASKA ATCA: 0.0159 µV/m/MHzGLUE: 0.0221 µV/m/MHz
“superior in design and execution to allprevious lunar neutrino searches”
— The Competition
LUNASKA?
Next step: bigger telescopes.
SKA-LOW would reach down toknown cosmic-ray flux.
Engineering Change Proposalsubmitted.
1018 1019 1020 1021 1022 1023
Energy (eV)
102
103
104
105
106
107
108
Diff
use
Flux
× E
nerg
y2 (e
V m−
2 s−
1 s
r−1)
measured flux
σsysuncertainty
cosmic rayflux limits RESUN
KalyazinGLUE
LUNASKA ATCALUNASKA Parkes
Parkes PAF
NuMoon
LOFAR
AuScope
Auger
SKA-lunar
past experimentfuture experiment
The Ron Factor
Discussed at Tasmania high-energy astrophysics student school:
“Ron Factor”degrees of separation, in terms of PhD supervision, from Ron
Ron is my supervisor → RF = 1.The highest we could find is RF = 3.What’s your Ron Factor?
58th Meeting of Nobel Physics Laureates in Lindau: 2008
• Ron somehow orchestrates for me to be one of the seven Australian representatives…
• Long story short:– At Lindau, I meet the best friend (Sahra) of my future wife, Anna– In 2010, I visit Sahra in Germany, she introduces me to Anna– The rest is history…
• I have a lot to thank Ron for!
Finally . . .
From Clancy’s PhD dedication:
(except, sadly, he’s now back in particle physics . . . )
“I’m very sorry Ron that I can’t be there. You’ve been agreat inspiration to me.”
Best wishes from Clancy, Anna and Diana