We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020.We use data from multiple missions–AstroSat,NuSTAR and XMM-Newton,for the purpose.The X-ray spectrum can be modeled as a ...We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020.We use data from multiple missions–AstroSat,NuSTAR and XMM-Newton,for the purpose.The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kαline emission,at all epochs.We determined the source’s X-ray flux and luminosity at these different epochs.We find significant variations in the source’s flux state.We also investigate the variations in the source’s spectral components during the observation period.We find that the photon index and hence the spectral shape follow the variations only over longer time periods.We probe the correlations between fluxes of different bands and their photon indices,and found no significant correlations between the parameters.展开更多
We report the result of simultaneous multi-wavelength observations of the TeV blazar Mrk 421 during February - March 2003. We observed Mrk 421 using the Pachmarhi Array of Cerenkov Telescopes （PACT） of Tata Institut...We report the result of simultaneous multi-wavelength observations of the TeV blazar Mrk 421 during February - March 2003. We observed Mrk 421 using the Pachmarhi Array of Cerenkov Telescopes （PACT） of Tata Institute of Fundamental Research at Pachmarhi, India. Other simultaneous data were taken from the literature and public data archives. We have analyzed the high quality X-ray （2-20 keV） observations from the NASA Rossi X-Ray Timing Explorer （RXTE）. We obtained a possible correlated variability between X-ray and J band （1.25 μ） near infrared （NIR） wavelength. This is the first case of X-ray and NIR correlated variability in Mrk 421 or any high energy peaked （HBL） blazar. The correlated variability reported here indicates a similar origin for the NIR and X-ray emissions. The emission is not affected much by the environment of the surrounding medium of the central engine of Mrk 421. The observations are consistent with the shock-in-jet model for the emissions.展开更多
It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X...It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands.A geometric interpretation and standard shock or stochastic acceleration models of blazar emission have difficulty reproducing these observed behaviors.The present paper introduces a linear acceleration by integrating the reconnection electric field into the particle transport model for the observed behaviors of Mrk 421.We note that strong evidence for evolution in characteristic of multi-wavelength spectral energy distribution including shifting the peak frequency,accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands provides an important electrostatic acceleration diagnostic in a blazar jet.Assuming suitable model parameters,we apply the results of the simulation to the 13-day flaring event in March 2010 of Mrk 421,concentrating on the evolution of multiwavelength spectral energy distribution characteristic by shifting the peak frequency.It is clear that the ratio of the electric field and magnetic field strength plays an important role in temporal evolution of the peak frequency of synchrotron spectral energy distribution component.We suggest it is reasonable that the electrostatic acceleration is responsible for the evolution of multi-wavelength spectral energy distribution characteristic by shifting the peak frequency.Based on the model results,we assert that the peak frequency of the synchrotron spectral energy distribution component may signify a temporary characteristic of blazars,rather than a permanent one.展开更多
We present optical identification results for four ROSAT PSPC soft X-ray companions of Mrk 231 based on the deep BATC 6660 A-band image and the optical spectra obtained by the 60/90cm Schmidt telescope and the 2.16 m ...We present optical identification results for four ROSAT PSPC soft X-ray companions of Mrk 231 based on the deep BATC 6660 A-band image and the optical spectra obtained by the 60/90cm Schmidt telescope and the 2.16 m telescope at the Xinglong Station, NAOC. Three optical counterparts are quasars with redshifts z> 1 and the remaining X-ray source is probably a background galaxy cluster. Therefore, none of these soft X-ray companions are physically connected with the central X-ray source Mrk 231. Incorporating the previous results of Arp 220 and Mrk 273 (Xia et al. 1998, 1999), we suggest that the apparent soft X-ray associations with ULIRGs are chance coincidence in most cases.展开更多
We simulated the R-band contribution of the host galaxy of TeV γ-ray BL Lac object Mrk 501 in different aperture sizes and seeing conditions. An intensive set of observations was acquired with the 1.02m optical teles...We simulated the R-band contribution of the host galaxy of TeV γ-ray BL Lac object Mrk 501 in different aperture sizes and seeing conditions. An intensive set of observations was acquired with the 1.02m optical telescope, managed by Yunnan Observatories, from 2010 May 15 to 18. Based on the host subtraction data usually used in the literature, the subtraction of host galaxy contamination results in significant seeing-brightness correlations. These correlations would lead to illusive large amplitude variations at short timescales, which will mask the intrinsic microvariability, thus giving rise to difficulty in detecting the intrinsic microvariability. Both aperture size and seeing condition influence the flux measurements, but the aperture size impacts the result more significantly. Based on the parameters of an elliptical galaxy provided in the literature, we simulated the host contributions of Mrk 501 in different aperture sizes and seeing conditions. Our simulation data of the host galaxy obviously weaken these significant seeing-brightness correlations for the host-subtracted brightness of Mrk 501, and can help us discover the intrinsic short timescale microvariability. The pure nuclear flux is -8.0 mJy in the R band, i.e., the AGN has a magnitude of R - 13.96 mag.展开更多
基金financial support from ISRO(Sanction Order:No.DS_2B-13013(2)/11/2020-Section2)funded by the National Aeronautics and Space Administration。
文摘We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020.We use data from multiple missions–AstroSat,NuSTAR and XMM-Newton,for the purpose.The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kαline emission,at all epochs.We determined the source’s X-ray flux and luminosity at these different epochs.We find significant variations in the source’s flux state.We also investigate the variations in the source’s spectral components during the observation period.We find that the photon index and hence the spectral shape follow the variations only over longer time periods.We probe the correlations between fluxes of different bands and their photon indices,and found no significant correlations between the parameters.
基金the National Natural Science Foundation of China(Grants 10573005 and 10125313)
文摘We report the result of simultaneous multi-wavelength observations of the TeV blazar Mrk 421 during February - March 2003. We observed Mrk 421 using the Pachmarhi Array of Cerenkov Telescopes （PACT） of Tata Institute of Fundamental Research at Pachmarhi, India. Other simultaneous data were taken from the literature and public data archives. We have analyzed the high quality X-ray （2-20 keV） observations from the NASA Rossi X-Ray Timing Explorer （RXTE）. We obtained a possible correlated variability between X-ray and J band （1.25 μ） near infrared （NIR） wavelength. This is the first case of X-ray and NIR correlated variability in Mrk 421 or any high energy peaked （HBL） blazar. The correlated variability reported here indicates a similar origin for the NIR and X-ray emissions. The emission is not affected much by the environment of the surrounding medium of the central engine of Mrk 421. The observations are consistent with the shock-in-jet model for the emissions.
基金the National Natural Science Foundation of China(Grant Nos.11673060,11763005,11873043 and 11991051)the Specialized Research Fund for Shandong Provincial Key Laboratory(Grant No.KLWH201804)the Research Foundation for Scientific Elitists of the Department of Education of Guizhou Province(Grant No.QJHKYZ[2018]068)。
文摘It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands.A geometric interpretation and standard shock or stochastic acceleration models of blazar emission have difficulty reproducing these observed behaviors.The present paper introduces a linear acceleration by integrating the reconnection electric field into the particle transport model for the observed behaviors of Mrk 421.We note that strong evidence for evolution in characteristic of multi-wavelength spectral energy distribution including shifting the peak frequency,accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands provides an important electrostatic acceleration diagnostic in a blazar jet.Assuming suitable model parameters,we apply the results of the simulation to the 13-day flaring event in March 2010 of Mrk 421,concentrating on the evolution of multiwavelength spectral energy distribution characteristic by shifting the peak frequency.It is clear that the ratio of the electric field and magnetic field strength plays an important role in temporal evolution of the peak frequency of synchrotron spectral energy distribution component.We suggest it is reasonable that the electrostatic acceleration is responsible for the evolution of multi-wavelength spectral energy distribution characteristic by shifting the peak frequency.Based on the model results,we assert that the peak frequency of the synchrotron spectral energy distribution component may signify a temporary characteristic of blazars,rather than a permanent one.
基金The BATC Survey is supPOrted be the Chinese Academy of Sciencesthe National Natural Science Foundation of ChinaThis wo
文摘We present optical identification results for four ROSAT PSPC soft X-ray companions of Mrk 231 based on the deep BATC 6660 A-band image and the optical spectra obtained by the 60/90cm Schmidt telescope and the 2.16 m telescope at the Xinglong Station, NAOC. Three optical counterparts are quasars with redshifts z> 1 and the remaining X-ray source is probably a background galaxy cluster. Therefore, none of these soft X-ray companions are physically connected with the central X-ray source Mrk 231. Incorporating the previous results of Arp 220 and Mrk 273 (Xia et al. 1998, 1999), we suggest that the apparent soft X-ray associations with ULIRGs are chance coincidence in most cases.
基金financial supports of the Key Research Program of the CAS(Grant No.KJZD-EW-M06)the National Natural Science Foundation of China(NSFC+3 种基金Grant No.11433004)the Ministry of Science and Technology of China(2016YFA0400700)the financial supports of the NSFC(Grant Nos.11273052 and U1431228)the Youth Innovation Promotion Association,CAS
文摘We simulated the R-band contribution of the host galaxy of TeV γ-ray BL Lac object Mrk 501 in different aperture sizes and seeing conditions. An intensive set of observations was acquired with the 1.02m optical telescope, managed by Yunnan Observatories, from 2010 May 15 to 18. Based on the host subtraction data usually used in the literature, the subtraction of host galaxy contamination results in significant seeing-brightness correlations. These correlations would lead to illusive large amplitude variations at short timescales, which will mask the intrinsic microvariability, thus giving rise to difficulty in detecting the intrinsic microvariability. Both aperture size and seeing condition influence the flux measurements, but the aperture size impacts the result more significantly. Based on the parameters of an elliptical galaxy provided in the literature, we simulated the host contributions of Mrk 501 in different aperture sizes and seeing conditions. Our simulation data of the host galaxy obviously weaken these significant seeing-brightness correlations for the host-subtracted brightness of Mrk 501, and can help us discover the intrinsic short timescale microvariability. The pure nuclear flux is -8.0 mJy in the R band, i.e., the AGN has a magnitude of R - 13.96 mag.
