摘要
We report on the discovery of unusual broad absorption lines(BALs)in the bright quasar SDSS J075133.35+134548.3 at z~1,using archival and newly obtained optical and NIR spectroscopic data.The BALs are detected reliably in HeⅠ*λ3889,HeⅠ*λ10830 and tentatively in AlⅢ,MgⅡ.These BALs show complex velocity structures consisting of two major components:a high-velocity component(HV),with a blueshifted velocity range ofΔv_(HV)~9300--3500 km s^(-1),which can be reliably detected in HeⅠ*λ10830,and tentatively in AlⅢand MgⅡ,whereas it is undetectable in HeⅠ*λ3889;and a low-velocity component(LV),withΔv_(LV)~3500--1800 km s^(-1),is only detected in HeⅠ*λ3889 and HeⅠ*λ10830.With the BALs from different ions,the HV outflowing gas can be constrained to have a density of nH~10^(10.3)-10^(11.4) cm^(-3),a column density of NH~10^(21) cm^(-2)and an ionization parameter of U~10^(-1.83)-10^(-1.72);inferring a distance of RHV~0.5 pc from the central continuum source with a monochromatic luminosityλLλ(5100)=7.0×10^(45)erg s^(-1)at 5100 A.This distance is remarkably similar to that of the normal broad line region(BLR)estimated from reverberation experiments,suggesting association of the BLR and the HV BAL outflowing gas.Interestingly,a blueshifted component is also detected in AlⅢand MgⅡbroad emission lines(BELs),and the AlⅢ/MgⅡof such a BEL component can be reproduced by the physical parameters inferred from the HV BAL gas.The LV BAL gas likely has a larger column density,a higher ionization level and hence a smaller distance than the HV BAL gas.Further spectroscopy with a high S/N ratio and broader wavelength coverage is needed to confirm this to shed new light on the possible connection between BALs and BELs.
基金
supported by the National Natural Science Foundation of China(NSFC,11573024,11473025,11421303,11573001and 11822301)
the National Basic Research Program of China(the 973 Program 2013CB834905and 2015CB857005)
supported by the NSFC(11503022)
the Natural Science Foundation of Shanghai(No.15ZR 1444200)
supported by the NSFC(11233002)
support from the Anhui Provincial NSF(1608085QA06)
Young Wanjiang Scholar program
funded by the Strategic Priority Research Program
the Emergence of Cosmological Structures(XDB09000000),National Astronomical Observatories,Chinese Academy of Sciences
the Special Fund for Astronomy from the Ministry of Finance
Funding for SDSS-Ⅲhas been provided by the Alfred P.Sloan Foundation
the Participating Institutions
the National Science Foundation
the U.S.Department of Energy Office of Science。
