Ni, Q.Q.NiBrandt, W. N.W. N.BrandtLuo, B.B.LuoGarmire, G. P.G. P.GarmireHall, P. B.P. B.HallPlotkin, R. M.R. M.PlotkinShemmer, O.O.ShemmerTimlin, J. D.J. D.TimlinVITO, FabioFabioVITOWu, J.J.WuYi, W.W.Yi2025-04-152025-04-1520220035-8711http://hdl.handle.net/20.500.12386/37083We present deeper Chandra observations for weak-line quasars (WLQs) in a representative sample that previously had limited X-ray constraints, and perform X-ray photometric analyses to reveal the full range of X-ray properties of WLQs. Only 5 of the 32 WLQs included in this representative sample remain X-ray undetected after these observations, and a stacking analysis shows that these 5 have an average X-ray weakness factor of >85. One of the WLQs in the sample that was known to have extreme X-ray variability, SDSS J1539+3954, exhibited dramatic X-ray variability again: it changed from an X-ray normal state to an X-ray weak state within ≈3 months in the rest frame. This short time-scale for an X-ray flux variation by a factor of ≳9 further supports the thick disc and outflow (TDO) model proposed to explain the X-ray and multiwavelength properties of WLQs. The overall distribution of the X-ray-to-optical properties of WLQs suggests that the TDO has an average covering factor of the X-ray emitting region of ~0.5, and the column density of the TDO can range from $N_{\rm H}\, \sim 10^{23-24}~{\rm cm}^{-2}$ to $N_{\rm H}\, \gtrsim 10^{24}~{\rm cm}^{-2}$, which leads to different levels of absorption and Compton reflection (and/or scattering) among WLQs.STAMPAenArticle10.1093/mnras/stac3942-s2.0-85126737461https://academic.oup.com/mnras/article/511/4/5251/65292492022MNRAS.511.5251NFIS/05 - ASTRONOMIA E ASTROFISICA