what are you looking at?
This is a side view of the AMANDA-II detector.
The small black dots arranged in vertical lines are sensors
along the AMANDA strings. The sensors at the top of the picture
are closest to the surface of the ice, and those near the bottom
are closest to the center of the earth.
The circles with color are optical sensors
that detected Cherenkov light in this event. The light
that arrives earliest are colored red,
and the latest is purple. All times
in between are colored like the rainbow (red, orange, yellow,
green, blue, purple). The larger circles have larger signals,
which implies more light has reached this sensor.
In this event, the earliest hits (red)
are lowest in the array. Since the general direction of the
particle that generated the light is upward toward the surface,
this event can only be generated by a high energy neutrino.
The boxes around the circles show the sensors
that were used finally in the track reconstruction. Some of
the information that is collected by AMANDA-II is not very useful
so the reconstruction programs are trained to ignore non-essential
The circles with multiple colors show that
several photons hit that sensor within 10 microseconds (or so).