Rapid X-ray variability in Mkn 421 during a multiwavelength campaign
Monthly Notices of the Royal Astronomical Society, vol. 513, pp. 1662–1679
Abstract
ABSTRACT The study of short-term variability properties in AGN jets has the potential to shed light on their particle acceleration and emission mechanisms. We report results from a 4-d coordinated multiwavelength campaign on the highly peaked blazar (HBL) Mkn 421 in 2019 January. We obtained X-ray data from AstroSAT, BVRI photometry with the Whole Earth Blazar Telescope (WEBT), and TeV data from First G-APD Cherenkov Telescope to explore short-term multiwavelength variability in this HBL. The X-ray continuum is rapidly variable on time-scales of tens of ks. Fractional variability amplitude increases with energy across the synchrotron hump, consistent with previous studies; we interpret this observation in the context of a model with multiple cells whose emission spectra contain cutoffs that follow a power-law distribution. We also performed time-averaged and time-resolved (time-scales of 6 ks) spectral fits; a broken power-law model fits all spectra well; time-resolved spectral fitting reveals the usual hardening when brightening behaviour. Intra-X-ray cross-correlations yield evidence for the 0.6–0.8 keV band to likely lead the other bands by an average of 4.6 ± 2.6 ks, but only during the first half of the observation. The source displayed minimal night-to-night variability at all wavebands thus precluding significant interband correlations during our campaign. The broad-band SED is modelled well with a standard one-zone leptonic model, yielding jet parameters consistent with those obtained from previous SEDs of this source.
Authors 50
-
Alex G. Markowitz corresponding
University of California San Diego · Nicolaus Copernicus Astronomical Center · Polish Academy of Sciences
Affiliation as printed
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, PL-00-716 Warszawa, Poland
University of California, San Diego, Center for Astrophysics and Space Sciences, MC 0424, La Jolla, CA, 92093-0424, USA
-
Nicolaus Copernicus Astronomical Center · Polish Academy of Sciences
Affiliation as printed
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, PL-00-716 Warszawa, Poland
-
Institute of Nuclear Physics, Polish Academy of Sciences
Affiliation as printed
Institute of Nuclear Physics, Polish Academy of Sciences, PL-31-342 Kraków, Poland
-
Inter-University Centre for Astronomy and Astrophysics
Affiliation as printed
Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007, India
-
Tata Institute of Fundamental Research · North-West University
Affiliation as printed
Centre for Space Research, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa
Tata Institute of Fundamental Research, Mumbai 400005, India
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
Astronomical Observatory of the Jagiellonian University, ul. Orla 171, PL-30-244 Kraków, Poland
-
Affiliation as printed
Astronomical Observatory of the Jagiellonian University, ul. Orla 171, PL-30-244 Kraków, Poland
-
Jagiellonian University · Uniwersytet Komisji Edukacji Narodowej w Krakowie
Affiliation as printed
Astronomical Observatory of the Jagiellonian University, ul. Orla 171, PL-30-244 Kraków, Poland
Mt. Suhora Observatory, Pedagogical University, ul. Podchorazych 2, PL-30-084 Kraków, Poland
-
Affiliation as printed
Astronomical Observatory of the Jagiellonian University, ul. Orla 171, PL-30-244 Kraków, Poland
-
Affiliation as printed
EPT Observatories, Tijarafe, E-38780 La Palma, Spain
INAF, TNG Fundación Galileo Galilei, E-38712 La Palma, Spain
-
Nicolaus Copernicus Astronomical Center · Polish Academy of Sciences
Affiliation as printed
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, PL-00-716 Warszawa, Poland
-
Bulgarian Academy of Sciences · Institute of Astronomy and National Astronomical Observatory
Affiliation as printed
Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72 Tsarigradsko Shosse Blvd., 1784 Sofia, Bulgaria
-
Universidad Nacional Autónoma de México
Affiliation as printed
Universidad Nacional Autónoma de México, Instituto de Astronomía, AP 70-264, CDMX 04510, Mexico
-
National and Kapodistrian University of Athens
Affiliation as printed
Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens, GR-15784 Zografos, Athens, Greece
-
Universidad Nacional Autónoma de México
Affiliation as printed
Instituto de Astronomía, Universidad Nacional Autónoma de México, AP106, 22860 Ensenada, BC, Mexico
-
Affiliation as printed
Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, School of Space Science and Physics, Shandong University, Weihai, Shandong 264209, China
-
St Petersburg University · Pulkovo Observatory
Affiliation as printed
Astronomical Institute, St. Petersburg State University, 198504, St. Petersburg, Russia
Pulkovo Observatory, 196140 St. Petersburg, Russia
-
Affiliation as printed
University of Siena, Department of Physical Sciences, Earth and Environment, Astronomical Observatory, Via Roma 56, I-53100 Siena, Italy
-
Affiliation as printed
Osaka Kyoiku University, Institute of Astronomy, 4-698-1 Asahigaoka, Kashiwara 582-8582 Osaka, Japan
-
St Petersburg University · Pulkovo Observatory
Affiliation as printed
Astronomical Institute, St. Petersburg State University, 198504, St. Petersburg, Russia
Pulkovo Observatory, 196140 St. Petersburg, Russia
-
Affiliation as printed
Nordic Optical Telescope, Apartado 474, E-38700 Santa Cruz de La Palma, Spain
-
Osservatorio Astrofisico di Torino
Affiliation as printed
INAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, Italy
-
University of North Carolina at Chapel Hill
Affiliation as printed
University of North Carolina at Chapel Hill, Dept. of Physics and Astronomy, Chapel Hill, NC, 27599, USA
-
Affiliation as printed
Guadarrama Observatory, E-28430 Alpedrete, Madrid, Spain
-
Bulgarian Academy of Sciences · Institute of Astronomy and National Astronomical Observatory
Affiliation as printed
Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72 Tsarigradsko Shosse Blvd., 1784 Sofia, Bulgaria
-
Bulgarian Academy of Sciences · Institute of Astronomy and National Astronomical Observatory
Affiliation as printed
Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72 Tsarigradsko Shosse Blvd., 1784 Sofia, Bulgaria
-
Affiliation as printed
Osaka Kyoiku University, Institute of Astronomy, 4-698-1 Asahigaoka, Kashiwara 582-8582 Osaka, Japan
-
Osservatorio Astrofisico di Torino
Affiliation as printed
INAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese, Italy
-
Florida International University · Embry-Riddle Aeronautical University Daytona Beach Florida Campus · Embry–Riddle Aeronautical University
Affiliation as printed
Department of Physics, Florida International University, 11200 SW 8th St., Miami, FL 33199, USA
SARA Observatory, EMBRY-RIDDLE Aeronautical University, 1 Aerospace Boulevard, Daytona Beach, FL 32114-3900, USA
-
ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
-
Affiliation as printed
TU Dortmund, Experimental Physics 5, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
-
Affiliation as printed
University of Geneva, Department of Astronomy, Chemin d’Ecogia 16, CH-1290 Versoix, Switzerland
University of Geneva, Department of Astronomy, Chemin d'Ecogia 16, CH-1290 Versoix, Switzerland
-
ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
-
T. Bretz Aachen
ETH Zurich · Institute for Particle Physics and Astrophysics · RWTH Aachen University
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
RWTH Aachen UniversityTemplergraben 55, D-52062 Aachen, Germany
-
Affiliation as printed
TU Dortmund, Experimental Physics 5, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
TU Dortmund, Experimental Physics 5, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
-
ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
-
ETH Zurich · Institute for Particle Physics and Astrophysics
Affiliation as printed
ETH Zurich, Institute for Particle Physics and Astrophysics, Otto-Stern-Weg 5, CH-8093 Zurich, Switzerland
-
Affiliation as printed
TU Dortmund, Experimental Physics 5, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
-
Affiliation as printed
University of Würzburg, Institute for Theoretical Physics and Astrophysics, Emil-Fischer-Straße 31, Campus Hubland Nord, D-97074 Würzburg, Germany
-
Affiliation as printed
TU Dortmund, Experimental Physics 5, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
-
Affiliation as printed
University of Geneva, Department of Astronomy, Chemin d’Ecogia 16, CH-1290 Versoix, Switzerland
University of Geneva, Department of Astronomy, Chemin d'Ecogia 16, CH-1290 Versoix, Switzerland
-
Affiliation as printed
University of Geneva, Department of Astronomy, Chemin d’Ecogia 16, CH-1290 Versoix, Switzerland
University of Geneva, Department of Astronomy, Chemin d'Ecogia 16, CH-1290 Versoix, Switzerland
Cited by 13 stored of 13
13 results
No patents citing this paper on Lens.org (checked 2026-10-06).