Simultaneous X‐Ray and TeV Gamma‐Ray Observation of the TeV Blazar Markarian 421 during 2000 February and May

Krawczynski, H.; Sambruna, R. M.; Kohnle, Antje; Coppi, P.; Aharonian, F.; Akhperjanian, A. G.; Barrio, J. A.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Contreras, J. L.; Cortina, J.; Denninghoff, S.; Fonseca, V.; González, J. Becerra; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, Andréas; Hofmann, W.; Horns, D.; Ibarra, A.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Lampeitl, H.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Panter, M.; Plaga, R.; Plyasheshnikov, A.; Pühlhofer, G.; Rauterberg, Matthias; Röhring, A.; Rhode, W.; Rowell, G.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, Frank G.; Siems, M.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C. A.; Wittek, W.

doi:10.1086/322364

Cited by 92 publications

(75 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Publicly available lightcurve data from 1992 until today were collected from the Whipple (Kerrick et al 1995;Schubnell et al 1996;Buckley et al 1996;Maraschi et al 1999a), HEGRA (Aharonian et al 1999b,a;Krawczynski et al 2001b;Aharonian et al 2001Aharonian et al , 2002Aharonian et al , 2003Aharonian et al , 2004Kestel 2002), CAT (Piron 2000;Piron et al 2001), HESS (Aharonian et al 2005(Aharonian et al , 2006, MAGIC (Albert et al 2008a;Donnarumma et al 2009), and VERITAS (Rebillot et al 2006;Donnarumma et al 2009) experiments. We are also working on collecting more data from these and other experiments such as the Crimean GT-48 Cherenkov telescope (e.g.…”

Section: Lightcurve Datamentioning

confidence: 99%

Long-term lightcurves from combined unified very high energyγ-ray data

Tluczykont

Bernardini²,

Satalecka³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

Context. Very high-energy (VHE, E > 100 GeV) γ-ray data are a valuable input for multi-wavelength and multi-messenger (e.g. combination with neutrino data) studies. Aims. We aim at the conservation and homogenization of historical, current, and future VHE γ-ray-data on active galactic nuclei (AGN). Methods. We have collected lightcurve data taken by major VHE experiments since 1991 and combined them into long-term lightcurves for several AGN, and now provide our collected datasets for further use. Due to the lack of common data formats in VHE γ-ray astronomy, we have defined relevant datafields to be stored in standard data formats. The time variability of the combined VHE lightcurve data was investigated, and correlation with archival X-ray data collected by RXTE/ASM tested.Results. The combination of data on the prominent blazar Mrk 421 from different experiments yields a lightcurve spanning more than a decade. From this combined dataset we derive an integral baseline flux from Mrk 421 that must be lower than 33% of the Crab Nebula flux above 1 TeV. The analysis of the time variability yields log-normal flux variations in the VHE-data on Mrk 421. Conclusions. Existing VHE data contain valuable information concerning the variability of AGN and can be an important ingredient for multi-wavelength or multi-messenger studies. In the future, upcoming and planned experiments will provide more data from many transient objects, and the interaction of VHE astronomy with classical astronomy will intensify. In this context a unified and exchangeable data format will become increasingly important.

show abstract

Section: Lightcurve Datamentioning

confidence: 99%

Long-term lightcurves from combined unified very high energyγ-ray data

Tluczykont

Bernardini²,

Satalecka³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…A rather tight constraint is placed on these models by recent X-ray observations of Mkn 421 (Krawczynski et al 2001) which show the variability to be of the order of hours rather than days -the same timescale for variability was also seen in TeV γ-rays (Gaidos et al 1996). To fit with the one-zone models, for these variations one needs to invoke Doppler factors of order 50 (Krawczynki et al 2001 -the same result is derived from the MK97 calculations if one is to replace the day-long variability timescale used there with a sub-hour one (t var 10 3 sec); then the relation δ = 267t −1/4 var which was quoted earlier gives δ 50).…”

Section: Homogeneous Synchrotron Self-compton Modelsmentioning

confidence: 99%

Models of Variability in Blazar Jets

Mastichiadis

Kirk

2002

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

During the last decade multiwavelength observations of blazars have revealed many interesting patterns in their emission across the EM spectrum. In the present article we will review the time-dependent one-zone models and the models which advocate an acceleration and a radiation zone, and we will make some comparisons between them, especially in light of recent observations of the so-called TeV blazars.

show abstract

“…Moreover, the X-ray emission is known to be highly correlated with the TeV emission (Błażejowski et al 2005;Katarzynski et al 2005;Qian et al 1998), but like other HBLs, shows moderate correlation with the GeV emission (Li et al 2013). It is highly variable and has been well studied during its flaring episodes by several authors (Aleksić et al 2010(Aleksić et al , 2012Shukla et al 2012;Isobe et al 2010;Krawczynski et al 2001;Acciari et al 2009;Ushio et al 2009;Tramacere et al 2009;Horan et al 2009;Lichti et al 2008;Fossati et al 2008;Albert et al 2007;Brinkmann et al 2003). A detailed A&A 580, A100 (2015) study of its quiescent state emission has been performed by Abdo et al (2011) with the best-sampled SED to date.…”

Section: Introductionmentioning

confidence: 99%

Underlying particle spectrum of Mkn 421 during the huge X-ray flare in April 2013

Sinha

Shukla

Misra

et al. 2015

A&A

View full text Add to dashboard Cite

Context. In April 2013, the nearby TeV blazar, Mkn 421, showed one of the largest flares in X-rays in the past decade. Aims. We study all multiwavelength data available during MJD 56 392 to 56 403, with special emphasis on X-ray data to understand the underlying particle energy distribution. Methods. We studied the correlations between the UV and gamma-ray bands with the X-ray band using the z-transformed discrete correlation function. We modelled the underlying particle energy spectrum with a single population of electrons emitting synchrotron radiation, and statistically fitted the simultaneous time-resolved data from Swift-XRT and NuSTAR. Results. The flux varied rapidly in the X-ray band, with a minimum doubling timescale of 1.69 ± 0.13 h. There were no corresponding flares in UV and gamma-ray bands. The variability in UV and gamma rays was relatively modest with ∼8% and ∼16%, respectively, and no significant correlation was found with the X-ray light curve. The observed X-ray spectrum shows a clear curvature that can be fit by a log parabolic spectral form. This is best explained as originating from a log parabolic electron spectrum. However, a broken power law or a power law with an exponentially falling electron distribution cannot be ruled out either. Moreover, the excellent broadband spectrum from 0.3-79 keV allows us to make predictions of the UV flux. We find that this prediction is compatible with the observed flux during the low state in X-rays. However, during the X-ray flares, depending on the adopted model, the predicted flux is a factor of 2-50 lower than the observed one. This suggests that the X-ray flares are probably caused by a separate population that does not contribute significantly to the radiation at lower energies. Alternatively, the underlying particle spectrum can be much more complex than those explored in this work.

show abstract

Simultaneous X‐Ray and TeV Gamma‐Ray Observation of the TeV Blazar Markarian 421 during 2000 February and May

Cited by 92 publications

References 24 publications

Long-term lightcurves from combined unified very high energyγ-ray data

Long-term lightcurves from combined unified very high energyγ-ray data

Models of Variability in Blazar Jets

Underlying particle spectrum of Mkn 421 during the huge X-ray flare in April 2013

Contact Info

Product

Resources

About