Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Articles Article Faculty Publications -Articles Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Long-term Optical and ?-Ray Variability of the Blazar PKS 1222+216 Description An account of the resource The ?-ray emission from flat-spectrum radio quasars (FSRQs) is thought to be dominated by the inverse Compton scattering of the external sources of photon fields, e.g., accretion disk, broad-line region (BLR), and torus. FSRQs show strong optical emission lines and hence can be a useful probe of the variability in BLR output, which is the reprocessed disk emission. We study the connection between the optical continuum, H? line, and ?-ray emissions from the FSRQ PKS 1222+216, using long-term (?2011-2018) optical spectroscopic data from Steward Observatory and ?-ray observations from Fermi Large Area Telescope (LAT). We measured the continuum (F C,opt) and H? (F H? ) fluxes by performing a systematic analysis of the 6029-6452 optical spectra. We observed stronger variability in F C,opt than F H? , an inverse correlation between the H? equivalent width and F C,opt, and a redder-when-brighter trend. Using discrete cross-correlation analysis, we found a positive correlation (DCF ? 0.5) between the F ??ray&gt;100 MeV and F C,opt (6024-6092 light curves with a time lag consistent with zero at the 2? level. We found no correlation between the F ??ray&gt;100 MeV and F H? light curves, probably dismissing the disk contribution to the optical and ?-ray variability. The observed strong variability in the Fermi-LAT flux and F ??ray&gt;100 MeV ? F C,opt correlation could be due to the changes in the particle acceleration at various epochs. We derived the optical-to-?-ray spectral energy distributions during the ?-ray flaring and quiescent epochs that show a dominant disk component with no variability. Our study suggests that the ?-ray emission zone is likely located at the edge of the BLR or in the radiation field of the torus. 2022. The Author(s). Published by the American Astronomical Society. Creator An entity primarily responsible for making the resource Ezhikode S.H.; Shukla A.; Dewangan G.C.; Pawar P.K.; Agarwal S.; Mathew B.; Akhil Krishna R. Source A related resource from which the described resource is derived Astrophysical Journal, Vol-939, No. 2 Publisher An entity responsible for making the resource available Institute of Physics Date A point or period of time associated with an event in the lifecycle of the resource 2022-01-01 Identifier An unambiguous reference to the resource within a given context <a href="https://doi.org/10.3847/1538-4357/ac9627" target="_blank" rel="noreferrer noopener">https://doi.org/10.3847/1538-4357/ac9627</a> <br /><br /><a href="https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141980215&amp;doi=10.3847%2F1538-4357%2Fac9627&amp;partnerID=40&amp;md5=7d7f00ebd27789a41ea585184a384026" target="_blank" rel="noreferrer noopener">https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141980215&amp;doi=10.3847%2f1538-4357%2fac9627&amp;partnerID=40&amp;md5=7d7f00ebd27789a41ea585184a384026</a> Rights Information about rights held in and over the resource All Open Access; Gold Open Access; Green Open Access Relation A related resource ISSN: 0004637X Format The file format, physical medium, or dimensions of the resource Online Language A language of the resource English Type The nature or genre of the resource Article Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Ezhikode S.H., Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune, 411007, India, Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Road, Bengaluru, 560029, India; Shukla A., Department of Astronomy, Astrophysics and Space Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India; Dewangan G.C., Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune, 411007, India; Pawar P.K., Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune, 411007, India; Agarwal S., Department of Astronomy, Astrophysics and Space Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore, 453552, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Road, Bengaluru, 560029, India; Akhil Krishna R., Department of Physics and Electronics, CHRIST (Deemed to be University, Hosur Road, Bengaluru, 560029, India