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Long term variability and correlation study of the blazar 3C 454.3 in radio, NIR and optical wavebands

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.author Sarkar, A.
dc.contributor.author Chitnis, V.R.
dc.contributor.author Gupta, A.C.
dc.contributor.author Gaur, H.
dc.contributor.author Patel, S.R.
dc.contributor.author Wiita, P.J.
dc.contributor.author Volvach, A.E.
dc.contributor.author Tornikoski, Merja
dc.contributor.author Chamani Velasco, Wara
dc.contributor.author Enestam, Sissi
dc.contributor.author Lähteenmäki, Anne
dc.contributor.author Tammi, Joni
dc.contributor.author Vera Rodríguez, Rafael
dc.contributor.author Volvach, L.N.
dc.date.accessioned 2020-01-17T13:27:03Z
dc.date.available 2020-01-17T13:27:03Z
dc.date.issued 2019-12-20
dc.identifier.citation Sarkar , A , Chitnis , V R , Gupta , A C , Gaur , H , Patel , S R , Wiita , P J , Volvach , A E , Tornikoski , M , Chamani Velasco , W , Enestam , S , Lähteenmäki , A , Tammi , J , Vera Rodríguez , R & Volvach , L N 2019 , ' Long term variability and correlation study of the blazar 3C 454.3 in radio, NIR and optical wavebands ' , Astrophysical Journal , vol. 887 , no. 2 , 185 . https://doi.org/10.3847/1538-4357/ab5281 en
dc.identifier.issn 0004-637X
dc.identifier.issn 1538-4357
dc.identifier.other PURE UUID: 3c857776-7a8c-499a-8346-f0e36895c00a
dc.identifier.other PURE ITEMURL: https://research.aalto.fi/en/publications/long-term-variability-and-correlation-study-of-the-blazar-3c-4543-in-radio-nir-and-optical-wavebands(3c857776-7a8c-499a-8346-f0e36895c00a).html
dc.identifier.other PURE FILEURL: https://research.aalto.fi/files/38244841/ms_Sarkar_v4.pdf
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/42503
dc.description.abstract We performed a long-term optical (B, V, R bands), infra-red (J and K bands) and radio band (15, 22, 37 GHz band) study on the flat spectrum radio quasar, 3C 454.3, using the data collected over a period of more than 8 years (MJD 54500–57500). The temporal variability, spectral properties and inter-waveband correlations were studied by dividing the available data into smaller segments with more regular sampling. This helped us constrain the size and the relative locations of the emission regions for different wavebands. Spectral analysis of the source revealed the interplay between the accretion disk and jet emission. The source predominantly showed a redder-when-brighter trend, though we observed a bluer-when-brighter trend at high flux levels which could be signatures of particle acceleration and radiative cooling. Significant correlations with near-zero lag were seen between various optical/infra-red bands, indicating that these emission regions are co-spatial. Correlations with a time lag of about 10–100 days are seen between optical/infra-red and radio bands indicating these emissions arise from different regions. We also observe the DCF peak lag change from year to year. We try to explain these differences using a curved jet model where the different emission regions have different viewing angles resulting in a frequency dependent Doppler factor. This variable Doppler factor model explains the variability timescales and the variation in DCF peak lag between the radio and optical emissions in different segments. Lags of 6-180 days are seen between emissions in various radio bands, indicating a core-shift effect. en
dc.format.mimetype application/pdf
dc.language.iso en en
dc.relation.ispartofseries Astrophysical Journal en
dc.relation.ispartofseries Volume 887, issue 2 en
dc.rights openAccess en
dc.title Long term variability and correlation study of the blazar 3C 454.3 in radio, NIR and optical wavebands en
dc.type A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä fi
dc.description.version Peer reviewed en
dc.contributor.department Tata Institute of Fundamental Research
dc.contributor.department Aryabhatta Research Institute of Observational Sciences (ARIES)
dc.contributor.department College of New Jersey
dc.contributor.department Crimean Astrophysical Observatory
dc.contributor.department Metsähovi Radio Observatory
dc.contributor.department Anne Lähteenmäki Group
dc.contributor.department Department of Electronics and Nanoengineering
dc.subject.keyword galaxies: active
dc.subject.keyword galaxies:jets
dc.subject.keyword methods: observational
dc.subject.keyword quasars: individual (3C 454.3)
dc.subject.keyword techniques: photometric
dc.identifier.urn URN:NBN:fi:aalto-202001171618
dc.identifier.doi 10.3847/1538-4357/ab5281
dc.type.version acceptedVersion

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