Multiwavelength Variability of the Blazars Mrk 421 and 3C 454.3 in the High-State

Abstract

We report the results of photometric observations of the blazars Mrk 421 and 3C 454.3 designed to search for intraday variability (IDV) and short-term variability (STV). Optical photometric observations were spread over eighteen nights for Mrk 421 and seven nights for 3C 454.3 during our observing run in 2009-2010 at the 1.04 m telescope at ARIES, India. Genuine IDV is found for the source 3C 454.3 but not for Mrk 421. Genuine STV is found for both sources. Mrk 421 was revealed by the MAXI X-ray detector on the International Space Station to be in an exceptionally high flux state in 2010 January - February. We performed a correlation between the X-ray and optical bands to search for time delays and found a weak correlation with higher frequencies leading the lower frequencies by about ten days. The blazar 3C 454.3 was found to be in high flux state in November-December 2009. We performed correlations in optical observations made at three telescopes, along with X-ray data from the MAXI satellite and public release gamma-ray data from the Fermi space telescope. We found strong correlations between the gamma-ray and optical bands at a time lag of about four days but the X-ray flux is not correlated with either. We briefly discuss the possible reasons for the time delays between these bands within the framework of existing models for X-ray and gamma-ray emission mechanisms.

16 pages, 7 figures, 3 tables, aastex file was merged with manuscript file. now we have replaced the aastex file

References in corpus (15)

• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Observations of Mkn 421 with the MAGIC Telescope
• Rapid variability in TeV blazars: the case of PKS 2155-304
• TeV and Multi-wavelength Observations of Mrk 421 in 2006-2008
• Host galaxy subtraction of TeV candidate BL Lacertae objects
• Statistical analyses of long-term variability of AGN at high radio frequencies
• Swift and infra-red observations of the blazar 3C~454.3 during the giant X-ray flare of May 2005
• AGILE detection of a strong gamma-ray flare from the blazar 3C 454.3
• INTEGRAL observations of the blazar 3C454.3 in outburst
• The high activity of 3C 454.3 in autumn 2007. Monitoring by the WEBT during the AGILE detection
• INTEGRAL observations of the blazar Mrk 421 in outburst (Results of a multi-wavelength campaign)
• Bright X-ray flares from the BL Lac object Mrk 421, detected with MAXI in 2010 January and February
• In Orbit Performance of the MAXI/SSC onboard the ISS
• Suzaku Wide Band Analysis of the X-ray Variability of TeV Blazar Mrk 421 in 2006
• Simultaneous multi-wavelength observations of the TeV Blazar Mrk 421 during February - March 2003: X-ray and NIR correlated variability

Cited by in corpus (41)

• Flare-like variability of the Mg IIλ2800Å emission line in the gamma-ray blazar 3C 454.3
• Optical Flux and Spectral Variability of Blazars
• Multi-band optical variability studies of BL Lacertae
• X-ray Intraday Variability of Five TeV Blazars with NuSTAR
• Multi-band optical variability of three TeV Blazars on Diverse Timescales
• Multiwaveband Quasi--periodic Oscillation in the Blazar 3C 454.3
• Multiband optical variability of the blazar OJ 287 during its outbursts in 2015 -- 2016
• A peculiar multi-wavelength flare in the Blazar 3C 454.3
• Characterizing optical variability of OJ 287 in 2016 - 2017
• Multi-wavelength Intra-day Variability and Quasi-periodic Oscillation in Blazars
• Is the Ultra-High Energy Cosmic-Ray Excess Observed by the Telescope Array Correlated with IceCube Neutrinos?
• Long term variability and correlation study of the blazar 3C 454.3 in radio, NIR and optical wavebands
• A unified model for orphan and multi-wavelength blazar flares
• Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3
• Multi-band optical-NIR variability of blazars on diverse timescales
• The nature of the intra-night optical variability in blazars
• Multiwavelength variability study and search for periodicity of PKS 1510-089
• Multi-band optical variability of 3C 279 on diverse timescales
• Peak of spectral energy distribution play an important role in intra-day variability of Blazars?
• Multi-wavelength Temporal Variability of the Blazar 3C 454.3 during 2014 Activity Phase
• Multi-color optical monitoring of ten blazars from 2005 to 2011
• Multi-band Variability Analysis of Mrk 421
• X-ray Intraday Variability of the TeV Blazar Mrk 421 with {\it Chandra}
• An active state of the BL Lac Object Markarian 421 detected by INTEGRAL in April 2013
• Frequency dependent core shifts and parameter estimation for the blazar 3C 454.3
• Long-term optical spectroscopic variations in blazar 3C 454.3
• Kepler light curve analysis of the blazar W2R 1926+42
• Gamma-Ray Flares in Long Term Light Curve of 3C 454.3
• A time dependent approach to model X-ray and $\gamma$--ray light curves of Mrk 421 observed during the flare in February 2010
• Intra-day optical multi-band quasi-simultaneous observation of BL Lacertae object S5 0716+714 from 2013 to 2016
• Multi-wavelength study of Mrk 421 TeV flare observed with \emph{TACTIC} telescope in February 2010
• Optical Monitoring of the Seyfert Galaxy NGC 4151 and Possible Periodicities in the Historical Light Curve
• Optical variability modeling of newly identified blazar candidates behind Magellanic Clouds
• Revisiting radio variability of the blazar 3C 454.3
• Multi-band Optical Variability of the TeV Blazar PG 1553+113 in 2019
• Flux and spectral variability of Mrk 421 during its moderate activity state using NuSTAR: Possible accretion disc contribution?
• Multiband Optical Variability of the Blazar 3C 454.3 on Diverse Timescales
• Multi-band optical variability of a newly discovered twelve blazars sample from 2013-2019
• Optical Monitoring of OT 546 in 2009
• Multi-band optical variability of the blazar OP 313 in the outburst state during 2024-2025
• Microvariability Detection of Mrk 421