Variability and Proper Motion of X-ray Knots in the Jet of Centaurus A
| dc.contributor.author | Snios, Bradford | |
| dc.contributor.author | Wykes, Sarka | |
| dc.contributor.author | Nulsen, Paul E. J. | |
| dc.contributor.author | Kraft, Ralph P. | |
| dc.contributor.author | Meyer, Eileen T. | |
| dc.contributor.author | Birkinshaw, Mark | |
| dc.contributor.author | Worrall, Diana M. | |
| dc.contributor.author | Hardcastle, Martin J. | |
| dc.contributor.author | Roediger, Elke | |
| dc.contributor.author | Forman, William R. | |
| dc.contributor.author | Jones, Christine | |
| dc.date.accessioned | 2019-02-14T18:59:01Z | |
| dc.date.available | 2019-02-14T18:59:01Z | |
| dc.date.issued | 2019-01-22 | |
| dc.description.abstract | We report results from Chandra observations analyzed for evidence of variability and proper motion in the X-ray jet of Centaurus A. Using data spanning 15 years, collective proper motion of 11.3±3.3 mas yr We report results from Chandra observations analyzed for evidence of variability and proper motion in the X-ray jet of Centaurus A. Using data spanning 15 years, collective proper motion of 11.3±3.3 mas yr −1 , or 0.68±0.20c , is detected for the fainter X-ray knots and other substructure present within the jet. The three brightest knots (AX1A, AX1C, and BX2) are found to be stationary to an upper limit of 0.10c . Brightness variations up to 27% are detected for several X-ray knots in the jet. For the fading knots, BX2 and AX1C, the changes in spectral slope expected to accompany synchrotron cooling are not found, ruling it out and placing upper limits of ≃80 μG for each of their magnetic field strengths. Adiabatic expansion can account for the observed decreases in brightness. Constraints on models for the origin of the knots are established. Jet plasma overrunning an obstacle is favored as the generator of stationary knots, while moving knots are likely produced either by internal differences in jet speed or the late stages of jet interaction with nebular or cloud material. , or 0.68±0.20c , is detected for the fainter X-ray knots and other substructure present within the jet. The three brightest knots (AX1A, AX1C, and BX2) are found to be stationary to an upper limit of 0.10c . Brightness variations up to 27% are detected for several X-ray knots in the jet. For the fading knots, BX2 and AX1C, the changes in spectral slope expected to accompany synchrotron cooling are not found, ruling it out and placing upper limits of ≃80 μG for each of their magnetic field strengths. Adiabatic expansion can account for the observed decreases in brightness. Constraints on models for the origin of the knots are established. Jet plasma overrunning an obstacle is favored as the generator of stationary knots, while moving knots are likely produced either by internal differences in jet speed or the late stages of jet interaction with nebular or cloud material. | en_US |
| dc.description.sponsorship | Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number G07-18104X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. S.W., P.E.J.N., and R.P.K. were supported in part by NASA contract NAS8-03060. S.W. thanks the Harvard-Smithsonian CfA for a research fellowship. | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.3847/1538-4357/aafaf3 | en_US |
| dc.format.extent | 14 pages | en_US |
| dc.genre | journal articles preprints | en_US |
| dc.identifier.citation | Bradford Snios, Sarka Wykes, Paul E. J. Nulsen, Ralph P. Kraft, Eileen T. Meyer, Mark Birkinshaw, Diana M. Worrall, Martin J. Hardcastle, Elke Roediger, William R. Forman, Christine Jones , Variability and Proper Motion of X-ray Knots in the Jet of Centaurus A, The Astrophysical Journal, Volume 871, Number 2; https://iopscience.iop.org/article/10.3847/1538-4357/aafaf3 | en_US |
| dc.identifier.uri | http://hdl.handle.net/11603/12794 | |
| dc.identifier.uri | https://doi.org/10.3847/1538-4357/aafaf3 | |
| dc.language.iso | en_US | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology (JCET) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | © 2019. The American Astronomical Society. All rights reserved. | |
| dc.subject | galaxies | en_US |
| dc.subject | active – galaxies | en_US |
| dc.subject | individual (Centaurus A) – galaxies | en_US |
| dc.subject | jets – X-rays | en_US |
| dc.title | Variability and Proper Motion of X-ray Knots in the Jet of Centaurus A | en_US |
| dc.type | Text | en_US |