Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/29807
DC Field | Value | Language |
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dc.contributor.author | Shulevski, A. | en_US |
dc.contributor.author | Morganti, R. | en_US |
dc.contributor.author | Barthel, P. D. | en_US |
dc.contributor.author | Harwood, J. J. | en_US |
dc.contributor.author | BRUNETTI, GIANFRANCO | en_US |
dc.contributor.author | van Weeren, R. J. | en_US |
dc.contributor.author | Röttgering, H. J. A. | en_US |
dc.contributor.author | White, G. J. | en_US |
dc.contributor.author | Horellou, C. | en_US |
dc.contributor.author | Kunert-Bajraszewska, M. | en_US |
dc.contributor.author | Jamrozy, M. | en_US |
dc.contributor.author | Chyzy, K. T. | en_US |
dc.contributor.author | Mahony, E. | en_US |
dc.contributor.author | Miley, G. | en_US |
dc.contributor.author | Brienza, M. | en_US |
dc.contributor.author | Bîrzan, L. | en_US |
dc.contributor.author | Rafferty, D. A. | en_US |
dc.contributor.author | Brüggen, M. | en_US |
dc.contributor.author | Wise, M. W. | en_US |
dc.contributor.author | Conway, J. | en_US |
dc.contributor.author | de Gasperin, F. | en_US |
dc.contributor.author | Vilchez, N. | en_US |
dc.date.accessioned | 2021-01-18T09:32:18Z | - |
dc.date.available | 2021-01-18T09:32:18Z | - |
dc.date.issued | 2015 | en_US |
dc.identifier.issn | 0004-6361 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/29807 | - |
dc.description | LOFAR, the Low Frequency Array designed and constructed by ASTRON, has facilities in several countries, which are owned by various parties (each with their own funding sources), and which are collectively operated by the International LOFAR Telescope (ILT) foundation under a joint scientific policy. R.M. gratefully acknowledges support from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Advanced Grant RADIOLIFE-320745. This research made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of APLpy, an open-source plotting package for Python hosted at http://aplpy.github.com R.J.v.W. acknowledges the support by NASA through the Einstein Postdoctoral grant number PF2-130104 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. We thank the anonymous referee for the constructive comments that have improved the manuscript. | en_US |
dc.description.abstract | Context. Steep spectrum radio sources associated with active galactic nuclei (AGN) may contain remnants of past AGN activity episodes. Studying these sources gives us insight into the AGN activity history. Novel instruments like the LOw Frequency ARray (LOFAR) are enabling studies of these fascinating structures to be made at tens to hundreds of MHz with sufficient resolution to analyse their complex morphology. <BR /> Aims: Our goal is to characterize the integrated and resolved spectral properties of VLSS J1431+1331 and estimate source ages based on synchrotron radio emission models, thus putting constraints on the AGN duty cycle. <BR /> Methods: Using a broad spectral coverage, we have derived spectral and curvature maps, and used synchrotron ageing models to determine the time elapsed from the last time the source plasma was energized. We used LOFAR, Giant Metrewave Radio Telescope (GMRT) and Jansky Very Large Array (VLA) data. <BR /> Results: We confirm the morphology and the spectral index values found in previous studies of this object. Based on our ageing analysis, we infer that the AGN that created this source currently has very low levels of activity or that it is switched off. The derived ages for the larger source component range from around 60 to 130 Myr, hinting that the AGN activity decreased or stopped around 60 Myr ago. We observe that the area around the faint radio core located in the larger source component is the youngest, while the overall age of the smaller source component shows it to be the oldest part of the source. <BR /> Conclusions: Our analysis suggests that VLSS J1431.8+1331 is an intriguing, two-component source. The larger component seems to host a faint radio core, suggesting that the source may be an AGN radio relic. The spectral index we observe from the smaller component is distinctly flatter at lower frequencies than the spectral index of the larger component, suggesting the possibility that the smaller component may be a shocked plasma bubble. From the integrated source spectrum, we deduce that its shape and slope can be used as tracers of the activity history of this type of steep spectrum radio source. We discuss the implications this conclusion has for future studies of radio sources having similar characteristics. | en_US |
dc.language.iso | eng | en_US |
dc.title | AGN duty cycle estimates for the ultra-steep spectrum radio relic VLSS J1431.8+1331 | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.1051/0004-6361/201525632 | en_US |
dc.identifier.scopus | 2-s2.0-84946548568 | en_US |
dc.identifier.isi | 000365072200020 | en_US |
dc.identifier.url | https://www.aanda.org/articles/aa/full_html/2015/11/aa25632-15/aa25632-15.html | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 583 | en_US |
dc.relation.firstpage | A89 | en_US |
dc.type.referee | REF_1 | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | ASTRONOMY & ASTROPHYSICS | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.identifier.adsbibcode | 2015A&A...583A..89S | en_US |
dc.relation.ercsector | ERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_6 Stars and stellar systems | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.fulltext | With Fulltext | - |
item.grantfulltext | open | - |
item.languageiso639-1 | en | - |
item.openairetype | Article | - |
item.cerifentitytype | Publications | - |
crisitem.journal.journalissn | 0004-6361 | - |
crisitem.journal.ance | E016240 | - |
crisitem.author.dept | IRA Bologna | - |
crisitem.author.orcid | 0000-0003-4195-8613 | - |
Appears in Collections: | 1.01 Articoli in rivista |
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File | Description | Size | Format | |
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aa25632-15.pdf | PDF editoriale | 1.04 MB | Adobe PDF | View/Open |
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