Microlensing in H1413+117: disentangling line profile emission and absorption in a broad absorption line quasar

Abstract

On the basis of 16 years of spectroscopic observations of the four components of the gravitationally lensed broad absorption line (BAL) quasar H1413+117, covering the ultraviolet to visible rest-frame spectral range, we analyze the spectral differences observed in the P Cygni-type line profiles and have used the microlensing effect to derive new clues to the BAL profile formation. We first find that the absorption gradually decreases with time in all components and that this intrinsic variation is accompanied by a decrease in the intensity of the emission. We confirm that the spectral differences observed in component D can be attributed to a microlensing effect lasting at least a decade. We show that microlensing magnifies the continuum source in image D, leaving the emission line region essentially unaffected. We interpret the differences seen in the absorption profiles of component D as the result of an emission line superimposed onto a nearly black absorption profile. We also find that the continuum source and a part of the broad emission line region are likely de-magnified in component C, while components A and B are not affected by microlensing. Differential dust extinction is measured between the A and B lines of sight. We show that microlensing of the continuum source in component D has a chromatic dependence compatible with the thermal continuum emission of a standard Shakura-Sunyaev accretion disk. Using a simple decomposition method to separate the part of the line profiles affected by microlensing and coming from a compact region from the part unaffected by this effect and coming from a larger region, we disentangle the true absorption line profiles from the true emission line profiles. The extracted emission line profiles appear double-peaked, suggesting that the emission is occulted by a strong absorber, narrower in velocity than the full absorption profile, and emitting little by itself. We propose that the outflow around H1413+117 is constituted by a high-velocity polar flow and a denser, lower velocity disk seen nearly edge-on. Finally, we report on the first ground-based polarimetric measurements of the four components of H1413+117.

The different origins of high- and low-ionization broad emission lines revealed by gravitational microlensing in the Einstein cross

“…We emphasize as a caveat that MmD, at a given Doppler shift, cannot disentangle the case where a part of the line flux is magnified like the continuum while the other part is not microlensed at all, from the case where the line flux is microlensed but less magnified than the continuum, i.e., 1 < µ line < µ continuum (see Appendix A of Hutsemékers et al 2010). Nevertheless, when the line flux is entirely included in F Mµ (respectively in F M ) in some Doppler shift interval, it unambiguously indicates that this part of the line profile is magnified like the continuum (resp.…”

Microlensing of the broad line region in 17 lensed quasars

“…In order to provide a more global overview of the variety of signals which may be observed, we completed our main sample with five systems we studied elsewhere: SDSS J0924+0219 (Eigenbrod et al 2006a), H1413+117 (Hutsemékers et al 2010), J1131-1231 (Sluse et al 2007), HE 2149-2745 (Burud et al 2002), and Q2237+0305 (Eigenbrod et al 2008;Sluse et al 2011). This is not a complete list of known microlensed quasars (see e.g.…”

“…Following Sluse et al (2007) and Hutsemékers et al (2010), we assume that the spectrum of an observed lensed image F i is the superposition of 2 components, one component F M which is only macro-lensed and another one, F Mμ , both macro-and A62, page 6 of 28 Table 3. Physical quantities associated to the source quasar.…”

“…Pooley et al 2007;Floyd et al 2009;Hutsemékers et al 2010;Dai et al 2010;Blackburne et al 2011;Muñoz et al 2011). Studies of BLR microlensing are more sparse and detections have been reported only for a handful of systems (Richards et al 2004;Wayth et al 2005; Keeton et al 2006;Sluse et al 2007;Hutsemékers et al 2010).…”

Adaptive PSF fitting – a highly performing photometric method and light curves of the GLS H1413+117: time delays and micro-lensing effects

“…Most micro-lensing activity is seen for the D component, which variability lasts for at least several years (Chartas et al 2004;Jovanović 2005). Moreover, the micro-lensing of the D component shows a chromatic dependence (Hutsemékers et al 2010). This result is directly consistent with the estimation of the duration of the micro-lensing events in H1413+117 by Witt, Mao & Schechter (1995).…”