On the correlation between the X-ray and gamma-ray emission in TeV blazars

Walczewska, K.

doi:10.1051/0004-6361/200913128

Cited by 26 publications

(23 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Obviously, considerable changes in the effective Doppler factor could occur, which would further influence the detectability of high-and lowlevel (intrinsic) active source stages, i.e., even if the intrinsic flux would change only moderately, an order of magnitude difference in measured VHE fluxes may become possible. Moreover, the motion of components along curved trajectories could possibly also account for the observed super-quadratic correlation between the X-ray and VHE flux (Costamante 2008;Katarzynski & Walczewska 2010). Of course, this might only be expected as long as the lateral width of the jet remains smaller than the separation d of the binary, so that the effects caused by orbital motion will not be smeared out.…”

Section: Possible Implications Of a Binary Bh Modelmentioning

confidence: 99%

Short-term VHE variability in blazars: PKS 2155-304

Rieger¹,

Volpe²

2010

A&A

View full text Add to dashboard Cite

Context. The γ-ray blazar PKS 2155-304 has attracted considerable attention because of its extreme TeV variability characteristics during an exceptional flaring period in 2006. Among the observed key findings are (i) a minimum variability timescale as short as ∼200 s and (ii) highly variable TeV emission, which in the frequency interval [10 −4 Hz, 10 −2 Hz] can be described by a log-normal distribution and suggests an underlying multiplicative (and not additive) process. Aims. Simultaneously accounting for these findings appears difficult within conventional approaches. Following earlier suggestions for the TeV blazar Mkn 501, we explore a possible scenario where PKS 2155-304 is supposed to harbor a supermassive binary black hole system and where the observed TeV variability is dominated by emission from the less massive black hole. Methods. We analyze the constraints on the very high energy (VHE) source imposed by the observed variability characteristics and the integrated VHE luminosity output, and discuss its implications for a binary black hole system. Results. We show that for a secondary mass of m BH ∼ 10 7 M , fluctuations in the disk accretion rate that feed the jet could account for the observed red-noise type variability process down to frequencies of ∼10 −2 Hz. Jet curvature induced by orbital motion, on the other hand, could further relax constraints on the intrinsic jet speeds. Conclusions. Because a binary system can lead to different (yet not independent) periodicities in different energy bands, a longterm (quasi-) periodicity analysis could offer important insights into the real nature of the central engine of PKS 2155-304.

show abstract

Section: Possible Implications Of a Binary Bh Modelmentioning

confidence: 99%

Short-term VHE variability in blazars: PKS 2155-304

Rieger¹,

Volpe²

2010

A&A

View full text Add to dashboard Cite

show abstract

“…Alternative models are discussed in the literature. Recent papers include Katarzyński & Walczewska (2010), Böttcher & Dermer (2010), Gao et al (2010), Tammi & Duffy (2009), Lichti et al (2008), 34 Deceased. 35 Now at DESY, Platanenallee 6, 15738 Zeuthen, Germany.…”

Section: Introductionmentioning

confidence: 99%

TeV AND MULTI-WAVELENGTH OBSERVATIONS OF Mrk 421 IN 2006-2008

Acciari¹,

Aliu²,

Arlen³

et al. 2011

ApJ

141

View full text Add to dashboard Cite

We report on TeV γ -ray observations of the blazar Mrk 421 (redshift of 0.031) with the VERITAS observatory and the Whipple 10 m Cherenkov telescope. The excellent sensitivity of VERITAS allowed us to sample the TeV γ -ray fluxes and energy spectra with unprecedented accuracy where Mrk 421 was detected in each of the pointings. A total of 47.3 hr of VERITAS and 96 hr of Whipple 10 m data were acquired between 2006 January and 2008 June. We present the results of a study of the TeV γ -ray energy spectra as a function of time and for different flux levels. On 2008 May 2 and 3, bright TeV γ -ray flares were detected with fluxes reaching the level of 10 Crab. The TeV γ -ray data were complemented with radio, optical, and X-ray observations, with flux variability found in all bands except for the radio wave band. The combination of the Rossi X-ray Timing Explorer and Swift X-ray data reveal spectral hardening with increasing flux levels, often correlated with an increase of the source activity in TeV 1 The Astrophysical Journal, 738:25 (19pp), 2011 September 1 Acciari et al.γ -rays. Contemporaneous spectral energy distributions were generated for 18 nights, each of which are reasonably described by a one-zone synchrotron self-Compton model.

show abstract

“…The IC peaks of the spectra are connected with red and blue bold lines which show a shape characteristic of the different scenarios, namely a '"1" like shape characteristic of an "injection & cooling" scenario (top panel), a "wing" like shape line drawn by the IC peaks of the viewing angle θ. Since the observed flux is proportional to a high power of the Doppler factor a small change of θ (e.g., from 5 to 3 degrees) induces a significant increase of the observed emission [128]. Current available data do not constrain well the evolution of the VHE bump since the IC peak cannot be monitored yet, being below the threshold of current IACT and difficult to measure on short time scale by Fermi.…”

Section: Peak Frequency and Emission Level Correlation In Ssc Modelsmentioning

confidence: 98%

Active Galactic Nuclei under the scrutiny of CTA

Sol

Zech

Boisson

et al. 2013

Astroparticle Physics

Self Cite

View full text Add to dashboard Cite

Active Galactic Nuclei (hereafter AGN) produce powerful outflows which offer excellent conditions for efficient particle acceleration in internal and external shocks, turbulence, and magnetic reconnection events. The jets as well as particle accelerating regions close to the supermassive black holes (hereafter SMBH) at the intersection of plasma inflows and outflows, can produce readily detectable very high energy gamma-ray emission. As of now, more than 45 AGN including 41 blazars and 4 radiogalaxies have been detected by the present ground-based gamma-ray telescopes, which represents more than one third of the cosmic sources detected so far in the VHE gamma-ray regime. The future Cherenkov Telescope Array (CTA) should boost the sample of AGN detected in the VHE range by about one order of magnitude, shedding new light on AGN population studies, and AGN classification and unification schemes. CTA will be a unique tool to scrutinize the extreme high-energy tail of accelerated particles in SMBH environments, to revisit the central engines and their associated relativistic jets, and to study the particle acceleration and emission mechanisms, particularly exploring the missing link between accretion physics, SMBH magnetospheres and jet formation. Monitoring of distant AGN will be an extremely rewarding observing program which will inform us about the inner workings and evolution of AGN. Furthermore these AGN are bright beacons of gamma-rays which will allow us to constrain the extragalactic infrared and optical backgrounds as well as the intergalactic magnetic field, and will enable tests of quantum gravity and other "exotic" phenomena. (C) 201 Published by Elsevier B.V

show abstract

On the correlation between the X-ray and gamma-ray emission in TeV blazars

Cited by 26 publications

References 32 publications

Short-term VHE variability in blazars: PKS 2155-304

Short-term VHE variability in blazars: PKS 2155-304

TeV AND MULTI-WAVELENGTH OBSERVATIONS OF Mrk 421 IN 2006-2008

Active Galactic Nuclei under the scrutiny of CTA

Contact Info

Product

Resources

About