Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752
We present 18 GHz Australia Telescope Compact Array imaging of themegaparsec-scale quasar jet PKS 0637-752with angular resolution ~0.58.We draw attention to a spectacular train of quasi-periodic knots along the inner 11of the jet, with average separation ~1.1 arcsec (7.6 kpc projected). We consider...
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal Article |
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Institute of Physics Publishing Ltd.
2012
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/49699 |
| _version_ | 1848758296999100416 |
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| author | Godfrey, Leith Lovell, J. Burke-Spolaor, S. Ekers, Ronald Bicknell, G. Birkinshaw, M. Worrall, D. Jauncey, D. Schwartz, D. Marshall, H. Gelbord, J. Perlman, E. Georganopoulos, M. |
| author_facet | Godfrey, Leith Lovell, J. Burke-Spolaor, S. Ekers, Ronald Bicknell, G. Birkinshaw, M. Worrall, D. Jauncey, D. Schwartz, D. Marshall, H. Gelbord, J. Perlman, E. Georganopoulos, M. |
| author_sort | Godfrey, Leith |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present 18 GHz Australia Telescope Compact Array imaging of themegaparsec-scale quasar jet PKS 0637-752with angular resolution ~0.58.We draw attention to a spectacular train of quasi-periodic knots along the inner 11of the jet, with average separation ~1.1 arcsec (7.6 kpc projected). We consider two classes of model to explainthe periodic knots: those that involve a static pattern through which the jet plasma travels (e.g., stationary shocks)and those that involve modulation of the jet engine. Interpreting the knots as re-confinement shocks implies thejet kinetic power Qjet ~ 1046 erg s-1, but the constant knot separation along the jet is not expected in a realisticexternal density profile. For models involving modulation of the jet engine, we find that the required modulationperiod is 2×103 yr < t < 3×105 yr. The lower end of this range is applicable if the jet remains highly relativisticon kiloparsec scales, as implied by the IC/CMB model of jet X-ray emission. We suggest that the periodic jetstructure in PKS 0637-752 may be analogous to the quasi-periodic jet modulation seen in the microquasar GRS1915+105, believed to result from limit cycle behavior in an unstable accretion disk. If variations in the accretionrate are driven by a binary black hole, the predicted orbital radius is 0.7 pc a 30 pc, which corresponds to amaximum angular separation of ~0.1–5 mas. |
| first_indexed | 2025-11-14T09:41:45Z |
| format | Journal Article |
| id | curtin-20.500.11937-49699 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:41:45Z |
| publishDate | 2012 |
| publisher | Institute of Physics Publishing Ltd. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-496992023-02-22T06:24:24Z Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 Godfrey, Leith Lovell, J. Burke-Spolaor, S. Ekers, Ronald Bicknell, G. Birkinshaw, M. Worrall, D. Jauncey, D. Schwartz, D. Marshall, H. Gelbord, J. Perlman, E. Georganopoulos, M. individual (PKS0637-752) quasars galaxies active jets We present 18 GHz Australia Telescope Compact Array imaging of themegaparsec-scale quasar jet PKS 0637-752with angular resolution ~0.58.We draw attention to a spectacular train of quasi-periodic knots along the inner 11of the jet, with average separation ~1.1 arcsec (7.6 kpc projected). We consider two classes of model to explainthe periodic knots: those that involve a static pattern through which the jet plasma travels (e.g., stationary shocks)and those that involve modulation of the jet engine. Interpreting the knots as re-confinement shocks implies thejet kinetic power Qjet ~ 1046 erg s-1, but the constant knot separation along the jet is not expected in a realisticexternal density profile. For models involving modulation of the jet engine, we find that the required modulationperiod is 2×103 yr < t < 3×105 yr. The lower end of this range is applicable if the jet remains highly relativisticon kiloparsec scales, as implied by the IC/CMB model of jet X-ray emission. We suggest that the periodic jetstructure in PKS 0637-752 may be analogous to the quasi-periodic jet modulation seen in the microquasar GRS1915+105, believed to result from limit cycle behavior in an unstable accretion disk. If variations in the accretionrate are driven by a binary black hole, the predicted orbital radius is 0.7 pc a 30 pc, which corresponds to amaximum angular separation of ~0.1–5 mas. 2012 Journal Article http://hdl.handle.net/20.500.11937/49699 10.1088/2041-8205/758/2/L27 Institute of Physics Publishing Ltd. unknown |
| spellingShingle | individual (PKS0637-752) quasars galaxies active jets Godfrey, Leith Lovell, J. Burke-Spolaor, S. Ekers, Ronald Bicknell, G. Birkinshaw, M. Worrall, D. Jauncey, D. Schwartz, D. Marshall, H. Gelbord, J. Perlman, E. Georganopoulos, M. Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title | Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title_full | Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title_fullStr | Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title_full_unstemmed | Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title_short | Periodic Structure in the Megaparsec-Scale Jet of PKS 0637-752 |
| title_sort | periodic structure in the megaparsec-scale jet of pks 0637-752 |
| topic | individual (PKS0637-752) quasars galaxies active jets |
| url | http://hdl.handle.net/20.500.11937/49699 |