SIMBAD references

We report a detection of an absorption line at ∼44.8 Å in a >500 ks Chandra HRC-S/LETG X-ray grating spectrum of the blazar H 2356-309. This line can be identified as intervening C V-Kα absorption, at z ~ 0.112, produced by a warm (log T = 5.1 K) intergalactic absorber. The feature is significant at a 2.9σ level (accounting for the number of independent redshift trials). We estimate an equivalent hydrogen column density of log N_H= 19.05(Z/Z_☉)^–1/cm2. Unlike other previously reported FUV/X-ray metal detections of warm-hot intergalactic medium (WHIM), this C V absorber lies in a region with locally low galaxy density, at ∼2.2 Mpc from the closest galaxy at that redshift, and therefore is unlikely to be associated with an extended galactic halo. We instead tentatively identify this absorber with an intervening WHIM filament possibly permeating a large-scale, 30 Mpc extended, structure of galaxies whose redshift centroid, within a cylinder of 7.5 Mpc radius centered on the line of sight to H 2356-309, is marginally consistent (at a 1.8σ level) with the redshift of the absorber.