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J/ApJ/788/119   Properties of the highly ionized gas of quasars  (Lehner+, 2014)

Galactic and circumgalactic O VI and its impact on the cosmological metal and baryon budgets at 2<z≲3.5. Lehner N., O'Meara J.M., Fox A.J., Howk J.C., Prochaska J.X., Burns V., Armstrong A.A. <Astrophys. J., 788, 119 (2014)> =2014ApJ...788..119L (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Redshifts ; Atomic physics ; Line Profiles Keywords: galaxies: halos - galaxies: high-redshift - galaxies: starburst - intergalactic medium - quasars: absorption lines Abstract: We present the first results from our NASA Keck Observatory Database of Ionized Absorbers toward Quasars (KODIAQ) survey which aims to characterize the properties of the highly ionized gas of galaxies and their circumgalactic medium (CGM) at 2<z<4. We select absorbers optically thick at the Lyman limit (τLL>1, logNHI>17.3) as probes of these galaxies and their CGM where both transitions of the O VI doublet have little contamination from the Lyα, β forests. We found 20 absorbers that satisfy these rules: 7 Lyman limit systems (LLSs), 8 super-LLSs (SLLSs) and 5 damped Lyα (DLAs). The O VI detection rate is 100% for the DLAs, 71% for the LLSs, and 63% for the SLLSs. When O VI is detected, log(N_O VI_)=14.9±0.3, an average O VI column density substantially larger and with a smaller dispersion than found in blind O VI surveys at similar redshifts. Strong O VI absorption is therefore nearly ubiquitous in the CGM of z∼2-3 galaxies. The total velocity widths of the O VI profiles are also large (200≤ΔυO VI_≤400 km/s). These properties are quite similar to those seen for O VI in low-z star-forming galaxies, and therefore we hypothesize that these strong CGM O VI absorbers (with τLL>1) at 2<z≲3.5 also probe outflows of star-forming galaxies. The LLSs and SLLSs with no O VI absorption have properties consistent with those seen in cosmological simulations tracing cold streams feeding galaxies. When the highly ionized (Si IV and O VI) gas is taken into account, we determine that the τLL>1 absorbers could contain as much as 3%-14% of the cosmic baryon budget at z∼2-3, only second to the Lyα forest. We conservatively show that 5%-20% of the metals ever produced at z∼2-3 are in form of highly ionized metals ejected in the CGM of galaxies. Description: All data in this sample were acquired with the HIgh Resolution Echelle Spectrometer (HIRES; Vogt et al. 1994SPIE.2198..362V) on the Keck I telescope on Mauna Kea. These data were obtained by different PIs from different institutions with Keck access, and hundreds of spectra of QSOs at 0<z<6, most being at z∼2-4, were collected. This provides one of the richest assortments of high-z QSO spectra at high spectral resolution (6-8 km/s) and high signal-to-noise (many with S/N>20-50). We were awarded a NASA Astrophysics Data Analysis Program (ADAP) grant (PI Lehner) to perform the data reduction and coaddition of the individual exposures of the entire KOA QSO database to study in detail the highly ionized plasma associated with τLL>1 absorbers at 2<z<4. We plan to release the entire KODIAQ database to the scientific community in 2015. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 77 20 Data Sample Summary table8.dat 67 256 Results from the Profile Fits
See also: VII/23 : Absorption Lines in QSO Spectra (Ellis+ 1978) VII/69 : Asiago Catalogue of QSOs (Barbieri+ 1983) J/AJ/112/62 : Quasar absorption-line systems (Tanner+ 1996) J/ApJ/508/200 : QSO low-z Lyα absorbers (Tripp+, 1998) J/MNRAS/346/1103 : Redshifts of damped Lymanα absorbers (Peroux+, 2003) J/ApJ/635/123 : The SDSS-DR3 damped Lyα survey (Prochaska+, 2005) J/ApJS/177/39 : Survey of low-redshift OVI absorbers (Tripp+, 2008) J/ApJ/775/78 : Lyman limit absorption systems in z∼3 QSOs (Fumagalli+, 2013) J/AJ/150/111 : KODIAQ DR1 (O'Meara+, 2015) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 11 A11 --- ID Source identifier 13- 14 I2 h RAh Hour of Right Ascension (J2000) 16- 17 I2 min RAm Minute of Right Ascension (J2000) 19- 23 F5.2 s RAs Second of Right Ascension (J2000) 25 A1 --- DE- Sign of the Declination (J2000) 26- 27 I2 deg DEd Degree of Declination (J2000) 29- 30 I2 arcmin DEm Arcminute of Declination (J2000) 32- 35 F4.1 arcsec DEs Arcsecond of Declination (J2000) 37- 51 A15 --- PI The original PI who acquired the data 53- 54 I2 10+3 Res [36/72] Spectral resolution 55 A1 --- n_Res [d] Note on Res (1) 57- 58 I2 --- S/N [6/54] Signal-to-noise ratio (2) 60- 64 F5.3 --- z QSO redshift 66- 72 F7.5 --- zabs Absorber redshift (3) 74- 77 F4.1 10+3km/s deltav Velocity difference (4)
Note (1): Note as follows: d = Also, R=36000 in the red (C IV, as well Si IV at high S/N). Note (2): Signal to noise (S/N) near O VI λ1031; generally, the S/N is higher at higher wavelengths. Note (3): The absorber redshift is determined by the centroid relative to the neutral (e.g., H I or O I) or low ionization (e.g., C II or Si II) species and will not generally match the exact redshift of the centroid to the observed O VI. Note (4): deltav=c(zem-zabs)/(1+zabs).
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 11 A11 --- ID Source identifier 13- 19 F7.5 --- z Redshift of the absorber 21 A1 --- f_z [ip] Flag on z (1) 23- 27 A5 --- Ion Fitted ion 29- 30 I2 --- Num [1/16] Component number 32- 37 F6.1 km/s Vel Velocity 39- 42 F4.1 km/s e_Vel Uncertainty in Vel 44- 48 F5.1 km/s b Doppler parameter 50- 53 F4.1 km/s e_b Uncertainty in b 55- 59 F5.2 [cm-2] logN Log column density 61- 64 F4.2 [cm-2] e_logN Uncertainty in logN 67 I1 --- Flag [0/3]? Fit flag (2)
Note (1): Flag as follows: i = intervening; p = proximate. Note (2): Flag as follows: 0 = result is robust; 1 = uncertain owing to the complexity of the absorption profile or on the necessity to rely on only one transition of the doublet; 2 = uncertain owing to the relative low S/N; 3 = uncertain results because the component is saturated in both transitions of the fitted doublet.
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 12-Jul-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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