The origins of a rich absorption line complex in a quasar at redshift 3.45

Abstract

We discuss the nature and origin of a rich complex of narrow absorption lines in the quasar J102325.31+514251.0 at redshift 3.447. We measure nine C IV(λλ1548, 1551) absorption line systems with velocities from −1400 to −6200 km s −1 , and full widths at half-minimum ranging from 16 to 350 km s −1 . We also detect other absorption lines in these systems, including H I, C III, N V, O VI and Si IV. Lower ionization lines are not present, indicating a generally high degree of ionization in all nine systems. The total hydrogen column densities range from 10 17.2 to 10 19.1 cm −2 . The tight grouping of these lines in the quasar spectrum suggests that most or all of the absorbing regions are physically related. We examine several diagnostics to estimate more directly the location and origin of each absorber. Four of the systems can be attributed to a quasar-driven outflow based on line profiles that are smooth and broad compared to thermal linewidths and to the typical absorption lines formed in intergalactic gas or galaxy haloes. Several systems also have other indicators of a quasar outflow origin, including partial covering of the quasar emission source (e.g. in systems with speeds too high for a starburstdriven flow), O VI column densities above 10 15 cm −2 and an apparent line-lock in C IV (in two of the narrow profile systems). A search for line variability yielded null results, although with very poor constraints because the comparison spectra have much lower resolution. Altogether (but not including the tentative line-lock) there is direct evidence for six of the nine systems forming in a quasar outflow. Consistent with a near-quasar origin, eight of the systems have metallicity values or lower limits in the range Z 1-8 Z . The lowest velocity system, which has an ambiguous location based on the diagnostics mentioned above, also has the lowest metallicity, Z 0.3 Z , and might form in a non-outflow environment farther from the quasar. Overall, however, this complex of narrow absorption lines can be identified with a highly structured, multicomponent outflow from the quasar. The high metallicities are similar to those derived for other quasars at similar redshifts and luminosities, and are consistent with evolution scenarios wherein quasars appear after the main episodes of star formation and metal enrichment in the host galaxies.

Nature and Origins of Rich Complexes of C iv Associated Absorption Lines

“…Several of these components exhibit partial covering indicative of intrinsic absorption. The metallicities in this line group are roughly solar or higher (Table 7), consistent with a quasar-driven outflow ejected from the metal-rich environs of a galactic nucleus (Hamann & Ferland 1999;Arav et al 2001;Hamann et al 2002;Dietrich et al 2003;Warner et al 2004;Gabel et al 2005;Nagao et al 2006;Simon & Hamann 2010a).…”

“…These interactions are predicted by quasar feedback models to shred and disperse interstellar clouds in the galaxies, thus creating small cloud fragments at a range of velocities (Hopkins & Elvis 2010;Faucher-Giguère & Kereš 2011;Faucher-Giguère et al 2012). This situation could produce highly-structured AAL complexes like we observe in J1008+3623 and other quasars in this study (see also C18; Simon & Hamann 2010a;Simon et al 2012, and refs. in Section 1). It provides a natural explanation for the in-situ creation of small partial-covering clouds far from the quasars.…”

The Surprisingly Constant Strength of O Vi Absorbers Over Cosmic Time

“…Fortunately, they can usually be identified by their saturated high-ion profiles, time variation of absorption, evidence for partial coverage of the continuum source, and/or presence of excited-state absorption lines (e.g. Hamann & Ferland 1999;Simon & Hamann 2010, and references therein). The remaining (non-intrinsic) proximate absorbers are included in the compilation presented in this paper.…”

Multiwavelength campaign on Mrk 509

“…The most distant AGN known, quasars at redshifts of 6 or more, have abundances at solar or super-solar levels (Hamann & Ferland 1993Pentericci et al 2002;Barth et al 2003;Dietrich et al 2003;Freudling et al 2003;Juarez et al 2009). Although the chemical enrichment of A&A 534, A41 (2011) the host likely predates the presence of the active nucleus (Simon & Hamann 2010), winds powered by the AGN could return this metal-enriched material to the IGM (Furlanetto & Loeb 2001;Cavaliere et al 2002;Germain et al 2009;Hopkins & Elvis 2010;Barai et al 2011). Their presence and feedback may also have a significant impact on the evolution of their host galaxies (Silk & Rees 1998;Scannapieco & Oh 2004;Granato et al 2004;Di Matteo et al 2005;Hopkins et al 2008;Somerville et al 2008).…”