Triple-ionized carbon associated with the low-density neutral hydrogen gas at 1.7 &lt;z&lt; 3.3: the integratedN H I–N C ivrelation

Kim, T.-S.; Carswell, R. F.; Mongardi, C.; Partl, Adrian M.; Mücket, J. P.; Barai, Paramita; Cristiani, S.

doi:10.1093/mnras/stv2990

Cited by 11 publications

(9 citation statements)

References 97 publications

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“…We remind readers that the publicly available VPFIT code has been extensively tested by the IGM community over three decades, including comparisons to curve-ofgrowth fit results. Our already published UVES and HIRES spectra (Kim et al 2007(Kim et al , 2013(Kim et al , 2016 were also refit with VPFIT v10.2 to be consistent with the new COS and STIS fits. While the new fits overall do not change significantly from the previous ones, the errors produced by VPFIT v10.2 tend to be larger when the components are at absorption wings.…”

Section: The Voigt Profile Fitting Analysissupporting

confidence: 77%

“…Table 1 lists the 24 QSOs observed with the UVES at the VLT or with the HIRES at Keck I, along with their emission redshift, analysed absorption redshift ranges and S/N per resolution element in the Lyα forest region. The UVES spectra are the same ones analysed by Kim et al (2007Kim et al ( , 2013Kim et al ( , 2016, while the HIRES spectra are the same ones described by Boksenberg & Sargent (2015). The UVES and HIRES spectra were sampled at 0.05Å and 0.04Å, respectively.…”

Section: Uves and Hires Datamentioning

confidence: 99%

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The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: data, transmitted flux, and H i column density,,

Kim¹,

Wakker²,

Nasir

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We present a new, uniform analysis of the H i transmitted flux (F) and H i column density ($N_{\mathrm{H\,{\small I}}}$) distribution in the low-density IGM as a function of redshift z for 0 < z < 3.6 using 55 HST/COS FUV (Δz = 7.2 at z < 0.5), five HST/STIS + COS NUV (Δz = 1.3 at z ∼ 1) and 24 VLT/UVES, and Keck/HIRES (Δz = 11.6 at 1.7 < z < 3.6) AGN spectra. We performed a consistent, uniform Voigt profile analysis to combine spectra taken with different instruments, to reduce systematics and to remove metal-line contamination. We confirm previously known conclusions on firmer quantitative grounds in particular by improving the measurements at z ∼ 1. Two flux statistics at 0 < F < 1, the mean H i flux and the flux probability distribution function (PDF), show that considerable evolution occurs from z = 3.6 to z = 1.5, after which it slows down to become effectively stable for z < 0.5. However, there are large sightline variations. For the H i column density distribution function (CDDF, f ∝ $N_{\rm H\,{\small I}}^{-\beta }$) at $\log (N_{\mathrm{H\,{\small I}}}/1\, {\mathrm{cm}^{-2}})$ ∈ [13.5, 16.0], β increases as z decreases from β = 1.60 at z ∼ 3.4 to β = 1.82 at z ∼ 0.1. The CDDF shape at lower redshifts can be reproduced by a small amount of clockwise rotation of a higher-z CDDF with a slightly larger CDDF normalization. The absorption line number per z (dn/dz) shows a similar evolutionary break at z ∼ 1.5 as seen in the flux statistics. High-$N_{\mathrm{H\,{\small I}}}$ absorbers evolve more rapidly than low-$N_{\mathrm{H\,{\small I}}}$ absorbers to decrease in number or cross-section with time. The individual dn/dz shows a large scatter at a given z. The scatter increases towards lower z, possibly caused by a stronger clustering at lower z.

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Section: The Voigt Profile Fitting Analysissupporting

confidence: 77%

Section: Uves and Hires Datamentioning

confidence: 99%

The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: data, transmitted flux, and H i column density,,

Kim¹,

Wakker²,

Nasir

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…Farina et al 2014). Therefore, most of the weak CIV systems in our sample are probably associated with N(HI) < 10 16 cm −2 (see also Kim et al 2016;D'Odorico et al 2016). In addition, we detect OVI only if we consider a velocity bin width of at least 10,000 km s −1 , although its signal is weak.…”

Section: Other Metal Speciesmentioning

confidence: 75%

“…CIV enrichment has even been suggested at lower N(HI) (Songaila 1998;Ellison et al 2000;Schaye et al 2003;D'Odorico et al 2016). This is the main reason why we start our analysis from a sample of CIV absorbers, as well as a better alignment of the CIV systems with other metal lines with respect to Lyα absorbers (Kim et al 2016).…”

Section: Datamentioning

confidence: 99%

Hunting for metals using XQ-100 Legacy Survey composite spectra

Perrotta

D’Odorico

Hamann

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We investigate the NV absorption signal along the line of sight of background quasars, in order to test the robustness of the use of this ion as criterion to select intrinsic (i.e. physically related to the quasar host galaxy) narrow absorption lines (NALs). We build composite spectra from a sample of ∼ 1000 CIV absorbers, covering the redshift range 2.55 < z < 4.73, identified in 100 individual sight lines from the XQ-100 Legacy Survey. We detect a statistical significant NV absorption signal only within 5000 km s −1 of the systemic redshift, z em . This absorption trough is ∼ 15σ when only CIV systems with N(CIV) > 10 14 cm −2 are included in the composite spectrum. This result confirms that NV offers an excellent statistical tool to identify intrinsic systems. We exploit the stacks of 11 different ions to show that the gas in proximity to a quasar exhibits a considerably different ionization state with respect to gas in the transverse direction and intervening gas at large velocity separations from the continuum source. Indeed, we find a dearth of cool gas, as traced by low-ionization species and in particular by MgII, in the proximity of the quasar. We compare our findings with the predictions given by a range of Cloudy ionization models and find that they can be naturally explained by ionization effects of the quasar.

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“…Additionally, Perrotta et al (2016) listed the absorption redshift of the 833 NALs consisting of metal absorptions along the 85 quasars in our sample. The Lyα absorption corresponding to these absorbers might be optically thin and hence can respond to the quasar's radiation (e.g., see Kim et al 2016). Therefore, even though we do not mask the Lyα region, however, if the corresponding metal lines such as C iv, Si iv, N v, C ii lies in the spectral region used in our analysis, we do mask a region of ±500 kms −1 around these metal absorption lines.…”

Section: Dla Sub-dla and Nalmentioning

confidence: 98%

Constraining the ratio of median pixel optical depth profile around z ~ 4 quasars using the longitudinal proximity effect

Jalan,

Chand,

Srianand

2021

Preprint

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We present a detailed study of the longitudinal proximity effect using a sample of 85 quasars spanning an emission redshift range of 3.5 z em 4.5 and Lyman continuum luminosity (L 912 ) ranging from 1.06×10 31 to 2.24×10 32 erg s −1 Hz −1 . We use the high-quality spectra of these quasars obtained at a spectral resolution of R ∼ 5100 and S/N ∼ 30 using X-SHOOTER spectrograph mounted on the Very Large Telescope (VLT). In our analysis, we compared the transmitted flux and pixel optical depth of the Lyα absorption originating from the vicinity of quasars to those from the general intergalactic medium by using a redshift matched control sample. The longitudinal proximity effect is found up to r 12 Mpc (proper) from quasars. By appropriately scaling up the pixel optical depth in the vicinity of quasars to account for the excess ionization by quasars, we constrain the ratio of median Hi optical depth in the vicinity of the quasar to that of the IGM (R τ (r)). The R τ (r) is found to be significantly higher than unity up to 6 Mpc from the quasar with a typical radial profile of the form R τ (r) = 1 + A × exp(−r/r 0 ) with A = 9.16 ± 0.68 and r 0 = 1.27 ± 0.08 Mpc. The integrated value of the scaled pixel optical depth over the radial bin of 0-6 Mpc is found to be higher by a factor of 2.55 ± 0.17 than the corresponding integrated value of the median pixel optical depth of the IGM. We also found R τ (r) to be luminosity dependent.

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Triple-ionized carbon associated with the low-density neutral hydrogen gas at 1.7 <z< 3.3: the integratedN _{H _I}–N _{C _iv}relation

Cited by 11 publications

References 97 publications

The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: data, transmitted flux, and H i column density,,

The evolution of the low-density H i intergalactic medium from z = 3.6 to 0: data, transmitted flux, and H i column density,,

Hunting for metals using XQ-100 Legacy Survey composite spectra

Constraining the ratio of median pixel optical depth profile around z ~ 4 quasars using the longitudinal proximity effect

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