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 Faculty Publications 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/. Creator An entity primarily responsible for making the resource Reshma, M.; Stalin, C.S.; Mandal, Amit Kumar; Kayal, Abhijit; Gudennavar, S.B.; Joseph, Prajwel Title A name given to the resource Detection of time delay between UV and X-ray variability in Mrk 1044 using AstroSat observations Date A point or period of time associated with an event in the lifecycle of the resource 01-01-2026 Source A related resource from which the described resource is derived Journal of High Energy Astrophysics;Volume;51;Issue;;Article No.;100552; Identifier An unambiguous reference to the resource within a given context <a href="https://doi.org/10.1016/j.jheap.2026.100552" target="_blank" rel="noreferrer noopener">https://doi.org/10.1016/j.jheap.2026.100552</a> <br /><br /><a href="https://www.scopus.com/pages/publications/105027550161?origin=resultslist" target="_blank" rel="noreferrer noopener">https://www.scopus.com/pages/publications/105027550161?origin=resultslist</a> Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Reshma M., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India; Mandal A.K., Center for Theoretical Physics of the Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland; Kayal A., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST University, Karnataka, Bangalore, 560029, India; Joseph P., Indian Institute of Astrophysics, Block II, Koramangala, Karnataka, Bangalore, 560034, India Description An account of the resource Active galactic nuclei are known to exhibit flux variations across the entire electromagnetic spectrum. Among these, correlations between UV/optical and X-ray flux variations serve as a key diagnostics for understanding the physical connection between the accretion disk and the corona. In this work, we present the results of analysis of ultraviolet (UV) and X-ray flux variations in the narrow line Seyfert 1 galaxy Mrk 1044. Simultaneous observations in the far-UV band (FUV: 1300 - 1800 and the X-ray band (0.5 - 7 keV) obtained during 31 August - 8 September 2018 with the Ultraviolet Imaging Telescope and the Soft X-ray Telescope onboard AstroSat were used for this study. Significant flux variability was detected in both FUV and X-ray bands. The fractional root mean square variability amplitude ( F var) was found to be 0.036 0.001 in the FUV band and 0.384 0.004 in the X-ray band. To explore potential time lag between the two bands, cross-correlation analysis was performed using both the interpolated cross-correlation function (ICCF) and just another vehicle for estimating lags in nuclei (JAVELIN) methods. Results from both approaches are consistent within 2 ? uncertainty, indicating that X-ray variations lead the FUV variations, with measured lags of 2.25 0.05 days (ICCF) and 2.35?0.01+0.02 days (JAVELIN). This is the first detection of a time delay between UV and X-ray variations in Mrk 1044. The observed UV lag supports the disk reprocessing scenario, wherein X-ray emission from the corona irradiates the accretion disk, driving the observed UV variability. 2026 Elsevier B.V. Subject The topic of the resource Active - galaxies; Galaxies; Galaxies - X-rays; Individual; Mrk 1044 - ultraviolet Publisher An entity responsible for making the resource available Elsevier B.V. Relation A related resource ISSN: 22144048; Language A language of the resource English Type The nature or genre of the resource Article Rights Information about rights held in and over the resource Restricted Access; Hardcopy may be available in the library Format The file format, physical medium, or dimensions of the resource online