| | |
| | |
Stat |
Members: 3643 Articles: 2'487'895 Articles rated: 2609
28 March 2024 |
|
| | | |
|
Article overview
| |
|
Evidence of bimodal physical properties of intervening, optically-thin CIII absorbers at z ~ 2.5 | Tae-Sun Kim
; Robert F. Carswell
; Drake Ranquist
; | Date: |
3 Dec 2015 | Abstract: | We present the Voigt profile analysis of 132 intervening CIV+CIII components
associated with optically-thin HI absorbers at 2.1 < z < 3.4 in the 19
high-quality UVES/VLT and HIRES/Keck QSO spectra. For log N(CIV) = [11.7,
14.1], N(CIII) is proportional to N(CIV) with an exponent (1.42 +- 0.11) and <
N(CIII)/N(CIV) > = 1.0 +- 0.3 with a negligible redshift evolution. For 54 CIV
components tied (aligned) with HI at log N(HI) = [12.2, 16.0] and log N(CIV) =
[11.8, 13.8], the gas temperature T_b estimated from absorption line widths is
well-approximated to a Gaussian peaking at log T_b ~ 4.4 +- 0.3 for log T_b =
[3.5, 5.5], with a negligible non-thermal contribution. For 32 of 54 tied
HI+CIV pairs, also tied with CIII at log N(CIII) = [11.7, 13.8], we ran both
photoionisation equilibrium (PIE) and non-PIE (using a fixed temperature T_b)
Cloudy models for the Haardt-Madau QSO+galaxy 2012 UV background. We find
evidence of bimodality in observed and derived physical properties.
High-metallicity branch absorbers have a carbon abundance [C/H]_temp > -1.0, a
line-of-sight length L_temp < 20 kpc, and a total (neutral and ionised)
hydrogen volume density log n(H, temp) = [-4.5, -3.3] and and log T_b = [3.9,
4.5]. Low-metallicity branch absorbers have [C/H]_temp < -1.0, L_temp = [20,
480] kpc and log n(H, temp) = [-5.2, -4.3] and log T_b ~ 4.5. High-metallicity
branch absorbers seem to be originated from extended disks, inner halos or
outflowing gas of intervening galaxies, while low-metallicity absorbers are
produced by galactic halos or the surrounding IGM filament. | Source: | arXiv, 1512.1050 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |