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Your search keyword '"Harwood, J. J."' showing total 9 results
Start Over Author "Harwood, J. J." Publisher oxford university press (oup)
9 results on '"Harwood, J. J."'

2. Low-frequency observations of the Giant Radio Galaxy NGC 6251

Author

Cantwell, T M, primary, Bray, J D, primary, Croston, J H, primary, Scaife, A M M, primary, Mulcahy, D D, primary, Best, P N, primary, Brüggen, M, primary, Brunetti, G, primary, Callingham, J R, primary, Clarke, A O, primary, Hardcastle, M J, primary, Harwood, J J, primary, Heald, G, primary, Heesen, V, primary, Iacobelli, M, primary, Jamrozy, M, primary, Morganti, R, primary, Orrú, E, primary, O’Sullivan, S P, primary, Riseley, C J, primary, Röttgering, H J A, primary, Shulevski, A, primary, Sridhar, S S, primary, Tasse, C, primary, and Van Eck, C L, primary

Published
2020
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3. Remnant radio-loud AGN in the Herschel-ATLAS field

Author

Mahatma, V H, primary, Hardcastle, M J, additional, Williams, W L, additional, Brienza, M, additional, Brüggen, M, additional, Croston, J H, additional, Gurkan, G, additional, Harwood, J J, additional, Kunert-Bajraszewska, M, additional, Morganti, R, additional, Röttgering, H J A, additional, Shimwell, T W, additional, and Tasse, C, additional

Published
2018
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4. LOFAR reveals the giant: a low-frequency radio continuum study of the outflow in the nearby FR I radio galaxy 3C 31

Author

Heesen, V, primary, Croston, J H, additional, Morganti, R, additional, Hardcastle, M J, additional, Stewart, A J, additional, Best, P N, additional, Broderick, J W, additional, Brüggen, M, additional, Brunetti, G, additional, Chyży, K T, additional, Harwood, J J, additional, Haverkorn, M, additional, Hess, K M, additional, Intema, H T, additional, Jamrozy, M, additional, Kunert-Bajraszewska, M, additional, McKean, J P, additional, Orrú, E, additional, Röttgering, H J A, additional, Shimwell, T W, additional, Shulevski, A, additional, White, G J, additional, Wilcots, E M, additional, and Williams, W L, additional

Published
2017
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5. Studying the late evolution of a radio-loud AGN in a galaxy group with LOFAR

Author

Savini, F, primary, Bonafede, A, additional, Brüggen, M, additional, Wilber, A, additional, Harwood, J J, additional, Murgia, M, additional, Shimwell, T, additional, Rafferty, D, additional, Shulevski, A, additional, Brienza, M, additional, Hardcastle, M J, additional, Morganti, R, additional, Röttgering, H, additional, Clarke, A O, additional, de Gasperin, F, additional, van Weeren, R, additional, Best, P N, additional, Botteon, A, additional, Brunetti, G, additional, and Cassano, R, additional

Published
2017
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6. Investigating the unification of LOFAR-detected powerful AGN in the Boötes field

Author

Morabito, Leah K., primary, Williams, W. L., additional, Duncan, Kenneth J., additional, Röttgering, H. J. A., additional, Miley, George, additional, Saxena, Aayush, additional, Barthel, Peter, additional, Best, P. N., additional, Bruggen, M., additional, Brunetti, G., additional, Chyży, K. T., additional, Engels, D., additional, Hardcastle, M. J., additional, Harwood, J. J., additional, Jarvis, Matt J., additional, Mahony, E. K., additional, Prandoni, I., additional, Shimwell, T. W., additional, Shulevski, A., additional, and Tasse, C., additional

Published
2017
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7. The Lockman Hole project: LOFAR observations and spectral index properties of low-frequency radio sources

Author

Mahony, E. K., primary, Morganti, R., additional, Prandoni, I., additional, van Bemmel, I. M., additional, Shimwell, T. W., additional, Brienza, M., additional, Best, P. N., additional, Brüggen, M., additional, Calistro Rivera, G., additional, de Gasperin, F., additional, Hardcastle, M. J., additional, Harwood, J. J., additional, Heald, G., additional, Jarvis, M. J., additional, Mandal, S., additional, Miley, G. K., additional, Retana-Montenegro, E., additional, Röttgering, H. J. A., additional, Sabater, J., additional, Tasse, C., additional, van Velzen, S., additional, van Weeren, R. J., additional, Williams, W. L., additional, and White, G. J., additional

Published
2016
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8. Investigating the spectra and physical nature of galaxy scale jets

Author

Webster, B., Croston, J. H., Harwood, J. J., Baldi, R. D., Hardcastle, M. J., Mingo, B., Röttgering, H. J. A., Webster, B., Croston, J. H., Harwood, J. J., Baldi, R. D., Hardcastle, M. J., Mingo, B., and Röttgering, H. J. A.

Abstract

Previous studies have shown that physically small, low-luminosity radio galaxies, which we refer to as galaxy scale jets (GSJ), could potentially have a significant effect upon the host galaxy’s evolution. Using 6-arcsec resolution images taken from the first release of the LOFAR Two Metre Sky Survey (LoTSS DR1), we identified a representative sample of nine potential GSJ for which we obtained high-resolution, 2–4 GHz data using the Karl G. Jansky Very Large Array (VLA). Using these data, we aim to verify the GSJ nature of these sources as well as investigating the potential role of feedback. Our VLA images reveal a diversity of structures, confirm the hosts for four of the sources and find that a fifth is the first known example of a galaxy-scale remnant showing that some radio galaxies never grow beyond the GSJ stage. We also derive spectral ages and the first estimates of the lobe expansion speeds of GSJ. We find our GSJ have maximum spectral ages of 60 Myr with most between about 5 and 20 Myr, consistent with being located along an evolutionary path joining compact sources and larger radio galaxies. We find lobe advance speeds a few times the local sound speed, with most GSJ predicted to be driving strong shocks into their environment and having a significant impact upon the host’s evolution. Our discovery of a remnant GSJ, which will eventually transfer all of its energy directly into the local environment, represents an important and previously hidden aspect of AGN life cycles.

9. Investigating the spectra and physical nature of galaxy scale jets

Author

Webster, B., Croston, J. H., Harwood, J. J., Baldi, R. D., Hardcastle, M. J., Mingo, B., Röttgering, H. J. A., Webster, B., Croston, J. H., Harwood, J. J., Baldi, R. D., Hardcastle, M. J., Mingo, B., and Röttgering, H. J. A.

Abstract

Previous studies have shown that physically small, low-luminosity radio galaxies, which we refer to as galaxy scale jets (GSJ), could potentially have a significant effect upon the host galaxy’s evolution. Using 6-arcsec resolution images taken from the first release of the LOFAR Two Metre Sky Survey (LoTSS DR1), we identified a representative sample of nine potential GSJ for which we obtained high-resolution, 2–4 GHz data using the Karl G. Jansky Very Large Array (VLA). Using these data, we aim to verify the GSJ nature of these sources as well as investigating the potential role of feedback. Our VLA images reveal a diversity of structures, confirm the hosts for four of the sources and find that a fifth is the first known example of a galaxy-scale remnant showing that some radio galaxies never grow beyond the GSJ stage. We also derive spectral ages and the first estimates of the lobe expansion speeds of GSJ. We find our GSJ have maximum spectral ages of 60 Myr with most between about 5 and 20 Myr, consistent with being located along an evolutionary path joining compact sources and larger radio galaxies. We find lobe advance speeds a few times the local sound speed, with most GSJ predicted to be driving strong shocks into their environment and having a significant impact upon the host’s evolution. Our discovery of a remnant GSJ, which will eventually transfer all of its energy directly into the local environment, represents an important and previously hidden aspect of AGN life cycles.

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