We report on the detection of two Ne VIII absorbers, at z = 0.61907 and z =
0.57052 in the HST/COS spectrum of background quasars SDSS J 080908.13+461925.6
and SBS 1122+594 respectively. The Ne VIII 770 line is at $3\sigma$
significance. In both instances, the NeVIII is found to be tracing gas with $T
10^5$ K, predominantly collisionally ionized, with moderate densities
of $n_H 10^-4$ $cm^-3$, sub-solar metallicities and total
hydrogen column densities of $N(H) 10^19$ $cm^2$. In the z =
0.61907 absorber, the low, intermediate ions and O VI are consistent with
origin in photoionized gas, with the O VI potentially having some contribution
from the warm collisional phase traced by Ne VIII. The z = 0.57052 system has H
I absorption in at least three kinematically distinct components, with one of
them having $b (H I) = 49 \pm 11$ $km s^-1$. The intermediate ionization
lines, O VI and Ne VIII are coincident in velocity with this component. Their
different line widths suggest warm temperatures of $T = (0.5 - 1.5) \times
10^5$ K. Both absorbers are residing in regions where there are several
luminous ($ L^*$) galaxies. The absorber at z = 0.57052 is within the
virial radius of a $2.6L^*$ galaxy, possibly associated with shock heated
circumgalactic material.
Description
[1706.04325] Detection of Two Intervening Ne VIII Absorbers Probing Warm Gas at z~0.6
%0 Generic
%1 pachat2017detection
%A Pachat, Sachin
%A Narayanan, Anand
%A Khaire, Vikram
%A Savage, Blair D.
%A Muzahid, Sowgat
%A Wakker, Bart P.
%D 2017
%K NeVIII absorption cgm gas group warm
%R 10.1093/mnras/stx1435
%T Detection of Two Intervening Ne VIII Absorbers Probing Warm Gas at z~0.6
%U http://arxiv.org/abs/1706.04325
%X We report on the detection of two Ne VIII absorbers, at z = 0.61907 and z =
0.57052 in the HST/COS spectrum of background quasars SDSS J 080908.13+461925.6
and SBS 1122+594 respectively. The Ne VIII 770 line is at $3\sigma$
significance. In both instances, the NeVIII is found to be tracing gas with $T
10^5$ K, predominantly collisionally ionized, with moderate densities
of $n_H 10^-4$ $cm^-3$, sub-solar metallicities and total
hydrogen column densities of $N(H) 10^19$ $cm^2$. In the z =
0.61907 absorber, the low, intermediate ions and O VI are consistent with
origin in photoionized gas, with the O VI potentially having some contribution
from the warm collisional phase traced by Ne VIII. The z = 0.57052 system has H
I absorption in at least three kinematically distinct components, with one of
them having $b (H I) = 49 \pm 11$ $km s^-1$. The intermediate ionization
lines, O VI and Ne VIII are coincident in velocity with this component. Their
different line widths suggest warm temperatures of $T = (0.5 - 1.5) \times
10^5$ K. Both absorbers are residing in regions where there are several
luminous ($ L^*$) galaxies. The absorber at z = 0.57052 is within the
virial radius of a $2.6L^*$ galaxy, possibly associated with shock heated
circumgalactic material.
@misc{pachat2017detection,
abstract = {We report on the detection of two Ne VIII absorbers, at z = 0.61907 and z =
0.57052 in the HST/COS spectrum of background quasars SDSS J 080908.13+461925.6
and SBS 1122+594 respectively. The Ne VIII 770 line is at $\sim 3\sigma$
significance. In both instances, the NeVIII is found to be tracing gas with $T
\gtrsim 10^5$ K, predominantly collisionally ionized, with moderate densities
of $n_{H} \lesssim 10^{-4}$ $cm^{-3}$, sub-solar metallicities and total
hydrogen column densities of $N(H) \gtrsim 10^{19}$ $cm^{2}$. In the z =
0.61907 absorber, the low, intermediate ions and O VI are consistent with
origin in photoionized gas, with the O VI potentially having some contribution
from the warm collisional phase traced by Ne VIII. The z = 0.57052 system has H
I absorption in at least three kinematically distinct components, with one of
them having $b (H I) = 49 {\pm} 11$ $km s^{-1}$. The intermediate ionization
lines, O VI and Ne VIII are coincident in velocity with this component. Their
different line widths suggest warm temperatures of $T = (0.5 - 1.5) \times
10^5$ K. Both absorbers are residing in regions where there are several
luminous ($ \gtrsim L^*$) galaxies. The absorber at z = 0.57052 is within the
virial radius of a $2.6L^*$ galaxy, possibly associated with shock heated
circumgalactic material.},
added-at = {2017-06-15T10:05:19.000+0200},
author = {Pachat, Sachin and Narayanan, Anand and Khaire, Vikram and Savage, Blair D. and Muzahid, Sowgat and Wakker, Bart P.},
biburl = {https://www.bibsonomy.org/bibtex/2568936edb37c2035a9db1306208ad30c/miki},
description = {[1706.04325] Detection of Two Intervening Ne VIII Absorbers Probing Warm Gas at z~0.6},
doi = {10.1093/mnras/stx1435},
interhash = {4a62236eaa0bd78d033068084a12a9ae},
intrahash = {568936edb37c2035a9db1306208ad30c},
keywords = {NeVIII absorption cgm gas group warm},
note = {cite arxiv:1706.04325Comment: 20 pages, 11 figures, 4 tables. Accepted by MNRAS},
timestamp = {2017-06-15T10:05:19.000+0200},
title = {Detection of Two Intervening Ne VIII Absorbers Probing Warm Gas at z~0.6},
url = {http://arxiv.org/abs/1706.04325},
year = 2017
}