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Observation Date (UT) Observation Lat

Canonical Name:PKS 2155-304
TeVCat Name:TeV J2158-302
Other Names:HESS J2158-302
Source Type:HBL
R.A.:21 58 52.7 (hh mm ss)
Dec.:-30 13 18 (dd mm ss)
Gal Long: 17.74 (deg)
Gal Lat: -52.25 (deg)
Distance: z=0.116
Flux:0.15 (Crab Units)
Energy Threshold:300 GeV
Spectral Index:3.53
Discovery Date:1999-06
Discovered By: Durham
TeVCat SubCat:Default Catalog

Source Notes:

Source position and its uncertainty:
From the HESS Online Catalog:
- R.A. (J2000): 21:58:52.7
- Dec. (J2000): -30:13:18
From Aharonian et al. (2005):
- state that the point source is located at a distance
in RA of 9 +/- 12 arcsec(stat) and in Dec of 14 +/- 10 arcsec(stat) from the position
of PKS 2155-304
- that position is not quoted
- systematic errors on the pointing are less than 20 arcsec in RA and declination

- The gamma-ray flux from PKS 2155-304 has been found to be variable (see references below)
- From Abramowski et al. (2010):
- the average flux was at the level of about 15% of the Crab between 2005-2007
From Aharonian et al. (2007):
- the gamma-ray flux reached a peak value of about 15 times
the Crab steady flux during flare in July 2006
From Aleksic et al. (2012):
- Significant variability was detected during these large-zenith-angle observations

Spectral Index:
From Abramowski et al. (2010):
- 3.53 +/- 0.06(stat) +/- 0.10(syst) for low state 2005 - 2007
From Aleksic et al. (2012):
- 3.5 +/- 0.2 (large-zenith-angle observations)

Seen by: Durham, H.E.S.S., CANGAROO, MAGIC
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