Show simple item record

dc.contributor.authorTingay, Steven
dc.contributor.authorMiller-Jones, James
dc.contributor.authorLenc, E.
dc.date.accessioned2023-01-12T13:54:59Z
dc.date.available2023-01-12T13:54:59Z
dc.date.issued2020
dc.identifier.citationTingay, S.J. and Miller-Jones, J.C.A. and Lenc, E. 2020. Archival VLBA Observations of the Cygnus A Nuclear Radio Transient (Cyg A-2) Strengthen the Tidal Disruption Event Interpretation. Astrophysical Journal Letters. 901 (1): ARTN L17.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/90031
dc.identifier.doi10.3847/2041-8213/abb60d
dc.description.abstract

We have analyzed archival Very Long Baseline Array (VLBA) data for Cygnus A between 2002 and 2013, to search for radio emission from the transient discovered in 2015 by Perley et al. approximately 0.″4 from the nucleus of Cygnus A (Cyg A-2). Perley et al. use Very Large Array and VLBA archival data (between 1989 and 1997) to show that the transient rises in flux density by a factor of at least 5 in less than approximately 20 yr. With the additional data presented here, we revise the rise time to between approximately 4 and 6 yr, based on a new detection of the source at 15.4 GHz from 2011 October. Our results strengthen the interpretation of Cyg A-2 as the result of a tidal disruption event (TDE), as we can identify the location of the compact object responsible for the TDE and can estimate the angular expansion speed of the resulting radio-emitting structures, equivalent to an apparent expansion speed of <0.9c. While our results are consistent with recent X-ray analyses, we can rule out a previously suggested date of early 2013 for the timing of the TDE. We favor a timing between early 2009 and late 2011. Applying the model of Nakar Piran, we suggest a TDE causing a mildly relativistic outflow with a (density-dependent) total energy >1049 erg. Due to the improved temporal coverage of our archival measurements, we find that it is unlikely that Cyg A-2 has previously been in a high luminosity radio state over the last 30 yr.

dc.languageEnglish
dc.publisherIOP PUBLISHING LTD
dc.relation.urihttp://dx.doi.org/10.3847/2041-8213/abb60d
dc.relation.sponsoredbyhttp://purl.org/au-research/grants/arc/DP200102471
dc.rights.urihttp://creativecommons.org/licenses/by/4.0
dc.subjectScience & Technology
dc.subjectPhysical Sciences
dc.subjectAstronomy & Astrophysics
dc.subjectActive galaxies
dc.subjectExtragalactic radio sources
dc.subjectExperimental techniques
dc.titleArchival VLBA Observations of the Cygnus A Nuclear Radio Transient (Cyg A-2) Strengthen the Tidal Disruption Event Interpretation
dc.typeJournal Article
dcterms.source.volume901
dcterms.source.number1
dcterms.source.issn2041-8205
dcterms.source.titleAstrophysical Journal Letters
dc.date.updated2023-01-12T13:54:59Z
curtin.departmentSchool of Elec Eng, Comp and Math Sci (EECMS)
curtin.accessStatusOpen access
curtin.facultyFaculty of Science and Engineering
curtin.contributor.orcidMiller-Jones, James [0000-0003-3124-2814]
curtin.contributor.orcidTingay, Steven [0000-0002-8195-7562]
curtin.contributor.researcheridMiller-Jones, James [B-2411-2013]
curtin.contributor.researcheridTingay, Steven [B-5271-2013]
curtin.identifier.article-numberARTN L17
dcterms.source.eissn2041-8213
curtin.contributor.scopusauthoridMiller-Jones, James [10044231400]
curtin.contributor.scopusauthoridTingay, Steven [7004903117]


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record

http://creativecommons.org/licenses/by/4.0
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by/4.0