CANGAROO Results

We observe ~1 TeV gamma rays with an imaging Cerenkov telescope of 3.8 m diameter having 256 pixels (Figure 1) in Woomera, South Australia.

Figure 1. CANGAROO telescope now in operation.

Observation since 1992 has detected TeV signals so far from four objects, Crab, PSR B1706-44, Vela and SN 1006 (see Table 1). The CANGAROO data are shown in Figures 2 to 5.

A telescope of 7 m aperture with 512 pixels camera will commence operation in the next year 1998, to uncover the southern sky of ~100 GeV gamma rays (see Figure 6).

Table 1. Summary of CANGAROO observations

Object

Threshold

(TeV)

Flux

(10-12cm-2s-1)

Comment

Crab

7

0.80

d=2 kpc

Vela

2.5

2.9

d=0.5 kpc

PSR 1706-44

2

3.5

d=1.8 kpc

PSR 1509-58

1.5

3.1

d=4.2 kpc

PSR 1055-52

2

< 0.95

d=1.5 kpc

SN1006

3

2.4

d=2 kpc

Cen A

2

< 1.5

z= 0.0018

EXO 0423-084

2

< 1.1

z=0.039

PKS 2005-489

2

< 1.1

z=0.071

PKS 2316-423

2

< 1.1

z=0.055

Figure 2. Energy spectrum of the Crab nebula appears to continue with a constant power index up to 50 TeV at least.

Figure 3. Significance map of the signal around the direction of PSR B1706-44 in the field of view.

Figure 4. Contour map of TeV gamma rays near Vela pulsar direction. The maximum intensity appears to be from gbirth place'', displaced from the position of Vela pulsar.

Figure 5. Significance map of the signal from Supernova Remnant 1006. Intensity of non-thermal X-rays (ASCA data) is shown by contour.

Figure 6. CANGAROO telescope will soon provide 100 GeV gamma ray data from objects in the southern sky, as shown by blue color, Its coverage of the sky is compared with a telescope in the northern sky (such as the Whipple 10 m telescope with ~500 pixels which becomes available also next year).


You can find more details in our publications.