Rich complexes of associated absorption lines (AALs) in quasar spectra provide unique information about gaseous infall, outflows, and feedback processes in quasar environments. We study five quasars at redshifts 3.1 to 4.4 with AAL complexes containing from 7 to 18 CIV 1548, 1551 systems in high-resolution spectra. These complexes span velocity ranges $\lesssim$3600 km/s within $\lesssim$8200 km/s of the quasar redshifts. All are highly ionised with no measurable low-ionisation ions like SiII or CII, and all appear to form in the quasar/host galaxy environments based on evidence for line locking, partial covering of the background light source, strong NV absorption, and/or roughly solar metallicities, and on the implausibility of such complexes forming in unrelated intervening galaxies. Most of the lines in all five complexes identify high-speed quasar-driven outflows at velocity shifts $v\lesssim -1000$ km/s. Four of the complexes also have lines at smaller blueshifted velocities that might form in ambient interstellar clouds, low-speed outflows or at feedback interfaces in the host galaxies where high-speed winds impact and shred interstellar clouds. The partial covering we measure in some of the high-speed outflow lines require small absorbing clouds with characteristic sizes $\lesssim$1 pc or $\lesssim$0.01 pc. The short survival times of these clouds require locations very close to the quasars, or cloud creation in situ at larger distances perhaps via feedback/cloud-shredding processes. The AAL complex in one quasar, J1008+3623, includes unusually narrow CIV systems at redshifted velocities $350\lesssim v\lesssim640$ km/s that are excellent candidates for gaseous infall towards the quasar, e.g., ''cold-mode" accretion or a gravitationally-bound galactic fountain.

Associated absorption lines (AALs) in quasar spectra are valuable probes of the gas kinematics and physical conditions in quasar environments. The host galaxies are by definition in an active evolution stage that might involve large-scale blowouts and/or cold-mode accretion (infall) from the intergalactic medium (IGM). We discuss rest-frame UV spectra of four redshift 2-3 quasars selected to have low-ionization AALs of Si II or C II that place unique density and distance constraints on the absorbers. Our analysis of the AALs yields the following results. One of the quasars, Q0119-046, has a rich complex of 11 AAL systems that appear to be infalling at measured speeds from similar to 0 to similar to 1150 s(-1) at distance similar to 5.7 kpc from the quasar. The range of ions detected, up to Ne VIII, indicates a wide range of densities from similar to 4 to similar to 2500 cm(-3). Partial covering the quasar emission source requires cloud sizes <1 pc and possibly <0.01 pc. The short dissipation times of these small clouds suggest that they are created in situ at their observed location, perhaps as dense condensations in cold-mode accreting gas from IGM. The AALs in the other three quasars have outflow speeds from similar to 1900 to similar to 3000 s(-1). Some of them also appear to have a range of densities based on the range of ions detected, including MgI lambda 2853 in Q0105+061. However, the absence of excited-state AALs yields only upper limits on their gas densities (less than or similar to 150 c(-3)) and large minimum distances (greater than or similar to 40 kpc) from the quasars. These AALs might represent highly extended quasar-driven outflows, although their actual physical relationships to the quasars cannot be established.

We discuss results from a survey of narrow absorption lines (NALs) in high-resolution spectra of 24 high-redshift quasars. We identify NALs that are intrinsic to quasar environments based on partial covering of the background light source and, secondarily, broad rounded line profiles. The intrinsic lines tend to be stronger and broader, with larger CIV column densities, compared to other NALs with intervening or ambiguous origins. The large velocity shifts of many intrinsic lines, nu > 2500 km s(-1), clearly indicate an origin in quasar outflows. We describe some interesting individual cases, including very large outflow velocities up to similar to 39,300 km s(-1), and rich multicomponent NAL complexes that also appear to have an outflow origin.

Narrow absorption line (NAL) outflows are an important yet poorly understood part of the quasar outflow phenomenon. We discuss one particular NAL outflow that has high speeds, time variability, and moderate ionizations like typical BAL flows, at an estimated location just ~5 pc from the quasar. It also has a total column density and line widths (internal velocity dispersions) ~100 times smaller than BALs, with no substantial X-ray absorption. We argue that radiative shielding (in the form of an X-ray/warm absorber) is not critical for the outflow acceleration and that the moderate ionizations occur in dense substructures that have an overall small volume filling factor in the flow. We also present new estimates of the overall incidence of quasar outflow lines; e.g., ~43% of bright quasars have a C IV NAL outflow while ~68% have a C IV outflow line of any variety (NAL, BAL, or mini-BAL).

We present the results of an exploratory study of broad-line region (BLR) metallicity in 34 2.2 <= z <= 4.6 quasars with far-infrared (FIR) luminosities (L-FIR) from 10(13.4) to <= 10(12.1) L-circle dot. Quasar samples sorted by L-FIR might represent an evolutionary sequence if the star formation rates (SFRs) in quasar hosts generally diminish across quasar lifetimes. We use rest-frame ultraviolet spectra from the Sloan Digital Sky Survey to construct three composite spectra sorted by L-FIR, corresponding to average SFRs of 4980, 2130 and <= 340 M-circle dot yr(-1) after correcting for a nominal quasar FIR contribution. The measured N V lambda 1240/C IV lambda 1550 and Si IV lambda 1397+ O IV] lambda 1402/C IV lambda 1550 emission line ratios indicate supersolar BLR metallicities in all three composites, with no evidence for a trend with the star formation rate. The formal derived metallicities, Z similar to 5-9 Z(circle dot), are similar to those derived for the BLRs of other quasars at similar redshifts and luminosities. These results suggest that the ongoing star formation in the host is not responsible for the metal enrichment of the BLR gas. Instead, the BLR gas must have been enriched before the visible quasar phase. These results for high quasar metallicities, regardless of L-FIR, are consistent with evolution scenarios wherein visibly bright quasars appear after the main episode(s) of star formation and metal enrichment in the host galaxies. Finally, young quasars, those more closely associated with a recent merger or a blowout of gas and dust, may exhibit tracers of these events, such as redder continuum slopes and higher incidence of narrow absorption lines. With the caveat of small sample sizes, we find no relation between L-FIR and the reddening or the incidence of absorption lines.

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(lambda lambda 1548, 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 HI, 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 less than or similar to 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 starburst-driven 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(circle dot). The lowest velocity system, which has an ambiguous location based on the diagnostics mentioned above, also has the lowest metallicity, Z <= 0.3 Z(circle dot), 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.

We present preliminary results from the largest-ever survey of high-resolution associated absorption line (AAL) region metallicities and physical properties in a sample of high redshift ( z > 3) quasars.

AbstractHigh-redshift quasars provide a unique glimpse into the early evolution of massive galaxies. The physical processes that trigger major bursts of star formation in quasar host galaxies (mergers and interactions) probably also funnel gas into the central regions to grow the super-massive black holes (SMBHs) and ignite the luminous quasar phenomenon. The globally dense environments where this occurs were probably also among the first to collapse and manufacture stars in significant numbers after the big bang. Measurements of the elemental abundances near quasars place important constraints on the nature, timing and extent of this star formation. A variety of studies using independent emission and absorption line diagnostics have shown that quasar environments have gas-phase metallicities that are typically a few times solar at all observed redshifts. These results are consistent with galaxy evolution scenarios in which large amounts of star formation (e.g., in the central regions) precede the visibly bright quasar phase. An observed trend for higher metallicities in more luminmous quasars (powered by more massive SMBHs) is probably tied to the well-known mass–metallicity relation among ordinary galaxies. This correlation and the absence of a trend with redshift indicate that mass is a more important parameter in the evolution than the time elapsed since the big bang.

AbstractWe present two ongoing studies of gas phase abundances around high redshift quasars. First, we examine broad emission line (BEL) metallicities for 29 quasars with 2.3 < z < 4.6 and far-infrared (far-IR) luminosities (LFIR) from 1013.4 to ≤ 1012.2 L⊙, corresponding to star formation rates (SFRs) of 6740 to ≤ 1360 M⊙ yr−1. Quasar samples sorted by LFIR might represent an evolutionary sequence if SFRs in quasar hosts generally diminish across quasar lifetimes. We create three composite spectra from rest-frame ultra-violet Sloan Digital Sky Survey spectra with increasing far-IR luminosity. We measure the N V(λ1240)/C IV(λ1550) and Si IV(λ1397)+O IV](λ1402)/C IV(λ1550) emission line flux ratios for each composite and find uniformly high (~5-10 times solar) metallicities for the three composites, and no evidence for changes in metal enrichment with changes in ongoing SFR. Second, we present preliminary results from the largest ever survey of high resolution associated absorption line (AAL) region metallicities and physical properties in a sample of high redshift (z > 3) quasars. This includes five quasars with previously known AALs at z > 4 and two well measured z ~3 quasars with unusually rich absorption spectra. We determine well-constrained metallicities of about twice solar for five AAL systems. We find a range of lower limits for AAL metallicities in the z > 4 quasars from 1/100ths solar to 3 times solar. Overall, these results for typically super-solar gas-phase metallicities near quasars are consistent with evolutionary schemes where the major episodes of star formation in the host galaxies occur before the visibly luminous quasar phase. High SFRs (comparable to ULIRGs) in the host galaxies are not clearly linked to younger or chemically less mature quasar environments.

We compare the metallicities in high-redshift quasars to the star formation rates (SFR) in their host galaxies using measurements of broad emission lines and far-infrared (FIR) luminosities. The FIR emission indicates the level of ongoing massive starbursts in the galaxy, whereas the abundance of metals in the gas surrounding the quasar indicates the amount of star formation which occurred before the visible quasar phase began. The results of this study can be used to constrain the late stages of starburst-quasar evolution. We detect high metallicities throughout the sample, up to several times solar, confirming that star formation must have begun before the visible quasar phase. However, we do not detect a trend in metallicity versus current SFR.

We employ absorption-line analysis, a unique technique to determine quasar abundances as well as the properties of the physical environment around the quasars such as densities, distances and ionizations, for several high-redshift quasars. We find that 80% of the associated systems we observe show partial coverage. Densities determined from the presence of low-ionization ions and absence of excited-state absorption are very low, from < 1 to 30 cm(-3). These low densities suggest very large distances from the quasar source, from 60 to 825 kpc, too far to be easily understood as instrinsic to the source, contradicting the partial coverage evidence. We contend that this may be due to shielding gas near the source, allowing the absorbing gas to remain close the source with low densities. We discuss implications of these findings for the star formation histories of the near-quasar environment.

Resumen en: Recent studies based on quasar emission lines suggest that quasar environments are typicaly metal rich, with metallicities near or above the solar val...