Transcript auger_talk_web - The Cosmic Ray Observatory Project

Solving the Mystery of the
Ultra-High Energy Cosmic Rays
The Pierre Auger Observatory
Southern Site: Malargue, Argentina
Pablo Bauleo
Physics Department
Colorado State University
Fort Collins
CO 80523
Northern Site: Southeast Colorado, USA
http://www.auger.org.ar
Historical high points
1912
Victor Hess
discovers
“penetrating radiation”
from space
1938
Pierre Auger discovers
Extensive air showers
D
Pb
Auger varied
distance and
lead covering
Fast electronic counters
1962: Penzias-Wilson: Cosmic Microwave Background
p+
CMB
 p + 0
 n + +
For energy > 5 * 1019
Greisen, Zatsepin-Kuzmin (GZK) Cut Off
Particles > 5 * 1019 eV
must be < ~ few*50 Mpc away
Today a lot is known about the cosmic ray flux…
Highest energy event:
3.2 x 1020 eV
Fly’s Eye in Utah in 1991
The Auger project
is focused on the
highest energies.
Energy (eV)
At the high end of the spectrum the energies are macroscopic
Highest energy events are around 2*1020 eV  30 Joules
This energy is concentrated in, say, one proton.
It corresponds to kinetic energy of…
…dropping my
laptop computer
from shoulder height
…a tennis ball
at 40 miles per
hour
…a person walking
slowly, deep in thought.
Flux @ 1020 eV  1 CR/(km2 sr century)
Cosmic Mysteries
Where do Ultra High Energy
Cosmic Rays Come From?
No convincing acceleration process
for explaining particle energy > 1020 eV
A handful of super-GZK events have been reported.
Sources of particles > 1020 eV must be
closer than about 50 Mpc because of CMB
No likely acceleration sites have been found nearby.
The highest energy cosmic rays should point
back to possible sources
Point sources or uniform on the sky?
The primary cosmic ray initiates a shower.
There are two basic detection techniques:
Up to order
1011 particles
(1) Particles reach ground
Height ~20 km.a.s.l
(2) Nitrogen fluorescence
10% duty factor – dark
nights
Height ~ 1500 m.a.s.l
Extracting information from an EAS
•
Tank timing
 Arrival direction
•
Number of particles in tanks
 Total Energy
•
Telescope image (digital camera like)
 Arrival direction
•
Light detected
 Total Energy
Redundant measurement for cross-checks
Animation of an event
measured in Argentina
The Auger Collaboration
• 18 Participating Countries - 50 Institutions, >280 Scientists
Argentina
Mexico
Australia
Netherlands
Bolivia*
Poland
Brazil
Slovenia
Czech Republic
Spain
France
South Korea
Germany
United Kingdom
Greece
USA
Italy
Vietnam*
•
Participating US institutions:
UCLA
Case Western
Chicago
Colorado
Colorado State
Fermilab (and ANL)
Louisiana State
Michigan Tech
Minnesota
Nebraska
New Mexico
Northeastern
Penn State
Utah
Auger
north is
planned in
Colorado
Auger south
is here.
Malargue is a small town on
the high plains not far from
a ski area in the Andes.
View of Los Leones
Fluorescence Site
Six Telescopes viewing 30°x30°
each
Schmidt Telescope
using 11 m2 mirrors
UV optical filter
(also: provide protection
from outside dust)
Schmidt corrector ring
opt. Filter
(MUG-6)
Camera with 440 PMTs
(Photonis XP 3062)
Atmospheric Monitoring
• LIDAR at each eye
• cloud monitors at each eye
• central laser facility
• regular balloon flights
steerable LIDAR
facilities
located at each FD eye
Central laser facility
(fiber linked to tank)
LIDAR at each FD
building
light attenuation length
Aerosol concentration
Balloon probes  (T,p)-profiles
Aligned Water Tanks
as seen from Los Leones
Water Tank in the Pampa
Communication
antenna
GPS antenna
Electronics enclosure
40 MHz FADC,
local triggers, 10 Watts
Battery
box
Solar Panel
three 9”
PMTs
Plastic tank with
12 tons of water
Installation
Chain
installation of electronics
receiving ~20 tanks/week
Tank Preparation and Assembly
Transportation into field
Water deployment
Central campus
with visitors center
Assembly building, yard
Los Leones
(fully operational)
Coihueco
(fully operational)
Los Morados
(fully operational)
Loma Amarilla
(in preparation)
Proposed Layout in Southeast Colorado
http://www.auger.org.ar