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Joint fit of Warm Absorbers in COS and HETG spectra of NGC 3783
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作者 Xiao-Dan Fu Shui-Nai Zhang +2 位作者 Wei Sun Shu Niu Li Ji 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第9期71-80,共10页
Warm Absorbers (WAs), as an important form of AGN outflows, show absorption in both the UV and X-ray bands. Using XSTAR generated photoionization models, for the first time we present a joint fit to the simultaneous... Warm Absorbers (WAs), as an important form of AGN outflows, show absorption in both the UV and X-ray bands. Using XSTAR generated photoionization models, for the first time we present a joint fit to the simultaneous observations of HST/COS and Chandra/HETG on NGC 3783. A total of five WAs explain well all absorption features from the AGN outflows, which are spread over a wide range of parameters: ionization parameter log~ from 0.6 to 3.8, column density logNH from 19.5 to 22.3 cm-2, velocity v from 380 to 1060 km s-1, and covering factor from 0.33 to 0.75. Not all the five WAs are consistent in pressure. Two of them are likely different parts of the same absorbing gas, and two of the other WAs may be smaller discrete clouds that are blown out from the inner region of the torus at different periods. The five WAs suggest a total mass outflowing rate within the range of 0.22-4.1 solar mass per year. 展开更多
关键词 GALAXIES individual (ngc 3783) - quasars absorption lines - ultraviolet galaxies - X-ray GALAXIES
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Correcting the Contamination of Second-order Spectra:Improving HαMeasurements in Reverberation Mapping Campaigns
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作者 Wen-Zhe Xi Kai-Xing Lu +5 位作者 Hai-Cheng Feng Sha-Sha Li Jin-Ming Bai Rui-Lei Zhou Hong-Tao Liu Jian-Guo Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第12期242-251,共10页
Long-term spectroscopic monitoring campaigns on active galactic nuclei(AGNs)provide a wealth of information about its interior structure and kinematics.However,a number of the observations suffer from the contaminatio... Long-term spectroscopic monitoring campaigns on active galactic nuclei(AGNs)provide a wealth of information about its interior structure and kinematics.However,a number of the observations suffer from the contamination of second-order spectra(SOS)which will introduce some undesirable uncertainties at the red side of the spectra.In this paper,we test the effect of SOS and propose a method to correct it in the time domain spectroscopic data using the simultaneously observed comparison stars.Based on the reverberation mapping(RM)data of NGC 5548 in2019,one of the most intensively monitored AGNs by the Lijiang 2.4 m telescope,we find that the scientific object,comparison star,and spectrophotometric standard star can jointly introduce up to~30%SOS for Grism 14.This irregular but smooth SOS significantly affects the flux density and profile of the emission line,while having little effect on the light curve.After applying our method to each spectrum,we find that the SOS can be corrected effectively.The deviation between corrected and intrinsic spectra is~2%,and the impact of SOS on time lag is very minor.This method makes it possible to obtain the HαRM measurements from archival data provided that the spectral shape of the AGN under investigation does not have a large change. 展开更多
关键词 techniques spectroscopic-methods data analysis-galaxies individual(ngc 5548)-(galaxies:)quasars emission lines
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