We present the results of the multi-epoch broadband spectral study of 1ES 2344+514 and study the evolution of physical parameters.We used nearly simultaneous data obtained from 2017 June 6 to 2022 August 6(MJD 57910–...We present the results of the multi-epoch broadband spectral study of 1ES 2344+514 and study the evolution of physical parameters.We used nearly simultaneous data obtained from 2017 June 6 to 2022 August 6(MJD 57910–59797)in optical,UV,X-ray andγ-ray wavebands from various instruments including Swift-UVOT,Swift-XRT,Nuclear Spectroscopic Telescope Array(NuSTAR),AstroSat(SXT and LAXPC),Fermi-LAT,and TeV flux from MAGIC.During 2017 July,1ES 2344+514 appeared to be in the highest flaring state compared to other periods.We used the 0.5–7.0 keV and 3.0–20.0 keV data,respectively,from SXT and LAXPC of AstroSat and also 0.3–8.0 keV and 3.0–79.0 keV data,respectively,from Swift-XRT and NuSTAR.A joint fit between SXT and LAXPC,and between Swift-XRT and NuSTAR has been done for constraining the synchrotron peak.A clear shift in the synchrotron peak has been observed,which included 1ES 2344+514 in the HSP BL Lac family.A“harder-when-brighter”trend is observed in X-rays,and the opposite trend,i.e.,“softer-when-brighter,”is seen in theγ-rays.The multi-epoch broadband spectral energy distributions(SEDs)of this source were built and studied to get an idea of the radiation processes.The SEDs were fitted using a steady-state leptonic one-zone synchrotron+SSC model,and the fitted parameters of the emission region are consistent with those of other TeV BL Lacs.In this study,we found a weak correlation tendency between bolometric luminosity and magnetic field(B),as well as between bolometric luminosity and the break Lorentz factor(γ_(break)).展开更多
We present our initial results from a study of 14 （U）LIRGs with a doublenucleus （z 〈0.15） and an AGN signature in the Chandra archive.The goals of our study are to search for more possible cases of binary AGNs an...We present our initial results from a study of 14 （U）LIRGs with a doublenucleus （z 〈0.15） and an AGN signature in the Chandra archive.The goals of our study are to search for more possible cases of binary AGNs and to investigate the X-ray properties and energy sources of these energetic objects,a major effort devoted specifically to searching for binary AGNs from （U）LIRGs.Our studies suggest that Mrk 266 might be a new candidate in hosting binary AGNs supported by X-ray observations.Our analysis shows that most （U）LIRGs are essentially weak X-ray sources and are not dominated by AGNs,due to both the lack of Fe K line detections and weak emission in the hard X-ray band.We find evidence for thermal emission with temperature kT ～ 0.7keV in seven nuclear regions,and this component is possibly associated with the nuclear or circumnuclear starburst.The soft and hard X-ray to far-infrared ratios also suggest that most （U）LIRGs are not energetically dominated by AGNs.Therefore,this study only provides one additional candidate of binary AGNs.We cannot rule out the existence of low luminosity AGNs and thus binary AGNs in all of them,particularly,those highly obscured and spatially unresolved systems.Nine of 14 （U）LIRGs,including three previously known binary AGNs and a new candidate Mrk 266,clearly have obvious X-ray counterparts to their double optical/near-IR nuclei.whereas only two out of 14 have one obvious X-ray counterpart detected.Additionally,Arp 220 and Mrk 273 are not spatially resolved owing to their small nuclear separations （～ 1″）,and no展开更多
基金support of the Department of Atomic Energy,Government of India,under project identification No.RT4002supported by Fermi vip Investigator grants NNX08AN56G,NNX08AN56G,NNX09AV10G,and NNX15AU81G。
文摘We present the results of the multi-epoch broadband spectral study of 1ES 2344+514 and study the evolution of physical parameters.We used nearly simultaneous data obtained from 2017 June 6 to 2022 August 6(MJD 57910–59797)in optical,UV,X-ray andγ-ray wavebands from various instruments including Swift-UVOT,Swift-XRT,Nuclear Spectroscopic Telescope Array(NuSTAR),AstroSat(SXT and LAXPC),Fermi-LAT,and TeV flux from MAGIC.During 2017 July,1ES 2344+514 appeared to be in the highest flaring state compared to other periods.We used the 0.5–7.0 keV and 3.0–20.0 keV data,respectively,from SXT and LAXPC of AstroSat and also 0.3–8.0 keV and 3.0–79.0 keV data,respectively,from Swift-XRT and NuSTAR.A joint fit between SXT and LAXPC,and between Swift-XRT and NuSTAR has been done for constraining the synchrotron peak.A clear shift in the synchrotron peak has been observed,which included 1ES 2344+514 in the HSP BL Lac family.A“harder-when-brighter”trend is observed in X-rays,and the opposite trend,i.e.,“softer-when-brighter,”is seen in theγ-rays.The multi-epoch broadband spectral energy distributions(SEDs)of this source were built and studied to get an idea of the radiation processes.The SEDs were fitted using a steady-state leptonic one-zone synchrotron+SSC model,and the fitted parameters of the emission region are consistent with those of other TeV BL Lacs.In this study,we found a weak correlation tendency between bolometric luminosity and magnetic field(B),as well as between bolometric luminosity and the break Lorentz factor(γ_(break)).
基金supported by the National Natural Science Foundation of China(Distinguished Young Scholars,Grant Nos.10425313,10833006 and 10621303)Chinese Academy of Sciences’Hundred Talent Program973 project of the Ministry of Science and Technology of China(GrantNo.2007CB815406)
文摘We present our initial results from a study of 14 （U）LIRGs with a doublenucleus （z 〈0.15） and an AGN signature in the Chandra archive.The goals of our study are to search for more possible cases of binary AGNs and to investigate the X-ray properties and energy sources of these energetic objects,a major effort devoted specifically to searching for binary AGNs from （U）LIRGs.Our studies suggest that Mrk 266 might be a new candidate in hosting binary AGNs supported by X-ray observations.Our analysis shows that most （U）LIRGs are essentially weak X-ray sources and are not dominated by AGNs,due to both the lack of Fe K line detections and weak emission in the hard X-ray band.We find evidence for thermal emission with temperature kT ～ 0.7keV in seven nuclear regions,and this component is possibly associated with the nuclear or circumnuclear starburst.The soft and hard X-ray to far-infrared ratios also suggest that most （U）LIRGs are not energetically dominated by AGNs.Therefore,this study only provides one additional candidate of binary AGNs.We cannot rule out the existence of low luminosity AGNs and thus binary AGNs in all of them,particularly,those highly obscured and spatially unresolved systems.Nine of 14 （U）LIRGs,including three previously known binary AGNs and a new candidate Mrk 266,clearly have obvious X-ray counterparts to their double optical/near-IR nuclei.whereas only two out of 14 have one obvious X-ray counterpart detected.Additionally,Arp 220 and Mrk 273 are not spatially resolved owing to their small nuclear separations （～ 1″）,and no
