A quasar with ultrastrong, ultraviolet Fe II emission

Abstract

We report the discovery of an unusual quasar, 2226-3905, found during a survey of quasar candidates. The ultraviolet spectrum (intrinsic frame) of the object is dominated by extremely strong Fe II emission. The emission lines are narrow (typical FWHM-2150 km S-1) a!ld show little trac~ of their usually broad wings. C III] A, 1909 appears t~ be blended w1th an Fe III multtplet and we identify Fe II lines originating from ~1gh-ene~gy ~ev~ls (-10 eV). We c~nsi~er two possible explanations: either the quasar 1S a .low-10mzatton broad absorption lme (BAL) quasar in which the sight-line does ~ot mtersect ~ny BAL clouds or Lyoc fluorescence is the main physical process involved m the format10n of Fe II. Our observations do not favour the BAL interpretation, but rather support the latter process. Higher resolution observations would give definite support to the Lyoc fluorescence.

THE CONNECTIONS BETWEEN THE UV AND OPTICAL Fe ii EMISSION LINES IN TYPE 1 AGNs

“…This could be the collisional excitation or increased Lyα fluorescence, which may be one of the very important additional mechanisms of the Fe II excitation (Penston 1987;Graham et al 1996;Sigut and Pradhan 1998;Bautista et al 2004 …”

“…Baldwin et al (2004) showed that a photoionization model may reproduce well the observed shape and the EW of the UV Fe II 2200-2800 bump, but only if a microturbulent gas motion is taken into account. The Fe II strength is also controlled by the column density as well (Joly 1987;Verner et al 2004;Ferland et al 2009;Sameshima et al 2011) and that the strong Fe II emission is connected with high density emitting regions (Joly 1991;Baldwin et al 1996;Lawrence et al 1997;Kuraszkiewicz et al 2000;Graham et al 1996;Harris et al 2013;Clowes et al 2013). …”

A Self‐consistent NLTE‐Spectra Synthesis Model of FeLoBAL QSOs

“…Two different templates for the Fe ii BELs were considered. The first consisted of a linear combination of five sets of Fe ii BELs from theoretical model calculations (Verner et al 1999), and the second was the observed Fe ii BEL spectrum of the strong emission-line QSO 2226À3905 (Graham et al 1996). For the absorption features, de Kool et al (2002) obtained a template distribution of line optical depth with respect to velocity in the broad absorption line region ( BALR) from the observed absorption profile of Fe ii k3004, an apparently unblended line of moderate strength.…”

Intrinsic Absorption in the QSO FIRST J121442.3+280329

“…The second approach is to use the observed Fe II BEL spectrum of the strong Fe II emission line QSO 2226[3905 (Graham, Clowes, & Campusano 1996) as a template for the spectrum of the background source. We extracted the Fe II BEL spectrum (Fig.…”

“…This power law is not the same as that shown in the paper mentioned above, FIG. 3.ÈComparison of the theoretical Fe II BEL spectra used to Ðt the Fe II BEL spectrum (Verner et al 1999) and the observed Fe II BEL spectrum of QSO 2226[3905 (Graham et al 1996).…”