Correlated time variability of multicomponent high-velocity outflows in J162122.54+075808.4

ABSTRACT We present a detailed analysis of time variability two distinct C iv broad absorption line (BAL) components seen in the spectrum J162122.54+075808.4 (zem = 2.1394) using observations from SDSS, NTT, and SALT taken at seven different epochs spanning about 15 yr. The blue-BAL component (with an ejection velocity, $v_{\rm e}\sim 37\, 500$ km s−1) is emerging that shows equivalent width variations kinematic shifts consistent with acceleration. red-BAL ($v_{\rm e} \sim 15\, 400$ three-component absorption. One subsequently disappearing. other show acceleration coupled variability. Interestingly, we find blue- to be correlated. While emission-line flux varies by more than 17 per cent during our monitoring period, available light curves (covering rest frame 1300–2300 Å) do not 0.1 mag continuum. This suggests ionizing are larger near-ultraviolet flux. However, correlated between BAL cannot explained solely photoionization models without structural changes. In framework disc wind models, any changes radial profiles density and/or velocity triggered either instabilities or radiation can explain observations. High-resolution spectroscopic J1621+0758 important understand physical conditions absorbing gas thereby constrain parameters models.