Milliarcsecond-scale structure in the gamma-ray loud quasar PKS 1622-297
We made a high-resolution VLBI observation of the gamma-ray loud quasar PKS 1622-297 with the HALCA spacecraft and ground radio telescopes at 5 GHz in 1998 February, almost 3 yr after the source exhibited a spectacular GeV gamma-ray flare. The source shows an elongated structure toward the west on t...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
| Published: |
Nihon Tenmon Gakkai
2006
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| Subjects: | |
| Online Access: | http://pasj.asj.or.jp/v58/n2/580203/580203a.html http://hdl.handle.net/20.500.11937/11513 |
| Summary: | We made a high-resolution VLBI observation of the gamma-ray loud quasar PKS 1622-297 with the HALCA spacecraft and ground radio telescopes at 5 GHz in 1998 February, almost 3 yr after the source exhibited a spectacular GeV gamma-ray flare. The source shows an elongated structure toward the west on the parsec scale. The visibility data are well modeled by three distinct components: a bright core and two weaker jet components. Comparison with previous observations confirms that the jet components have an apparent superluminal motion up to 12.1h-1 c, with the inner jet components having lower superluminal speeds. We applied the inverse Compton catastrophe model and derived a Doppler factor, d, of 2.45, which is rather lower than those of other gamma-ray loud active galactic nuclei (AGNs), suggesting that the source was in a more quiescent phase at the epoch of our observation. As an alternative probe of the subparsec-scale structure, we also present the results from multiepoch ATCA total flux monitoring, which indicate the presence of persistent intraday variability consistent with refractive interstellar scintillation. We examined the gamma-ray emission mechanism in light of these observations. |
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