%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 }