AN X-RAY WHIM METAL ABSORBER FROM A Mpc-SCALE EMPTY REGION OF SPACE

Journal Article · Tue Jul 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/753/2/137· OSTI ID:22039383

Zappacosta, L; Nicastro, F ^[1]; Krongold, Y ^[2]; Maiolino, R ^[3]

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1. INAF-Osservatorio Astronomico di Roma, via di Frascati 33, 00040 Monte Porzio Catone (Italy)
2. Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264, 04510 Mexico DF (Mexico)
3. Astrophysics Group, Cavendish Laboratory, 19 J.J. Thomson Avenue, Cambridge CB3 OHE (United Kingdom)

We report a detection of an absorption line at {approx}44.8 A 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-K{alpha} absorption, at z Almost-Equal-To 0.112, produced by a warm (log T = 5.1 K) intergalactic absorber. The feature is significant at a 2.9{sigma} level (accounting for the number of independent redshift trials). We estimate an equivalent hydrogen column density of log N{sub H} 19.05(Z/Z{sub Sun }){sup -1} cm{sup -2}. 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 {approx}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 1.8{sigma} level) with the redshift of the absorber.

• OSTI ID: 22039383
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 753; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
BL LACERTAE OBJECTS
DENSITY
DETECTION
FAR ULTRAVIOLET RADIATION
HYDROGEN
INTERGALACTIC SPACE
K ABSORPTION
METALS
QUASARS
RED SHIFT
UNIVERSE
X RADIATION
X-RAY GALAXIES