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 rprother@physics.adelaide.edu.au

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