2024-03-28T10:39:13Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1092732018-06-21T09:19:37Zcom_10261_37com_10261_4col_10261_290
Nicastro, F.
Barcons, Xavier
Paerels, F. B. S.
2015-01-12T14:31:20Z
2015-01-12T14:31:20Z
2013
Astrophysical Journal 769(2): 90 (2013)
http://hdl.handle.net/10261/109273
10.1088/0004-637X/769/2/90
http://dx.doi.org/10.13039/501100003981
http://dx.doi.org/10.13039/501100005184
http://dx.doi.org/10.13039/100010174
http://dx.doi.org/10.13039/100000104
http://dx.doi.org/10.13039/501100003329
We present the first results from our pilot 500 ks Chandra Low Energy Transmission Grating Large Program observation of the soft X-ray brightest source in the z ≳ 0.4 sky, the blazar 1ES 1553+113, aimed to secure the first uncontroversial detections of the missing baryons in the X-rays. We identify a total of 11 possible absorption lines, with single-line statistical significances between 2.2σ and 4.1σ. Six of these lines are detected at high single-line statistical significance (3.6 ≤ σ ≤ 4.1), while the remaining five are regarded as marginal detections in association with either other X-ray lines detected at higher significance and/or far-ultraviolet (FUV) signposts. Three of these lines are consistent with metal absorption at z ≃ 0, and we identify them with Galactic O I and C II. The remaining eight lines may be imprinted by intervening absorbers and are all consistent with being high-ionization counterparts of FUV H I and/or O VI intergalactic medium signposts. In particular, five of these eight possible intervening absorption lines (single-line statistical significances of 4.1σ, 4.1σ, 3.9σ, 3.8σ, and 2.7σ), are identified as C V and C VI Kα absorbers belonging to three WHIM systems at zX = 0.312, z X = 0.237, and 〈zX 〉 = 0.133, which also produce broad H I (and O VI for the zX = 0.312 system) absorption in the FUV. For two of these systems (zX = 0.312 and 0.237), the Chandra X-ray data led the a posteriori discovery of physically consistent broad H I associations in the FUV (for the third system the opposite applies), so confirming the power of the X-ray-FUV synergy for WHIM studies. The true statistical significances of these three X-ray absorption systems, after properly accounting for the number of redshift trials, are 5.8σ (z X = 0.312; 6.3σ if the low-significance O V and C V Kβ associations are considered), 3.9σ (zX = 0.237), and 3.8σ (zX 〉 = 0.133), respectively. © 2013. The American Astronomical Society. All rights reserved.
eng
openAccess
Chandra view of the warm-hot intergalactic medium toward 1ES 1553+113: Absorption-line detections and identifications. I
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