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CHANDRA VIEW OF THE WARM-HOT INTERGALACTIC MEDIUM TOWARD 1ES 1553+113: ABSORPTION-LINE DETECTIONS AND IDENTIFICATIONS. I.
- Source :
- Astrophysical Journal; 6/ 1/2013, Vol. 769 Issue 2, p1-13, 13p
- Publication Year :
- 2013
-
Abstract
- 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 Oi and C ii. The remaining eight lines may be imprinted by intervening absorbers and are all consistent with being high-ionization counterparts of FUV Hi and/or Ovi 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 Cv and C vi Kα absorbers belonging to three WHIM systems at z<subscript>X</subscript> = 0.312, z<subscript>X</subscript> = 0.237, and <z<subscript>X</subscript>> = 0.133, which also produce broad Hi (and Ovi for the z<subscript>X</subscript> = 0.312 system) absorption in the FUV. For two of these systems (z<subscript>X</subscript> = 0.312 and 0.237), the Chandra X-ray data led the a posteriori discovery of physically consistent broad Hi associations in the FUV (for the third system the opposite applies), so confirming the power of the X-ray-FUV synergy forWHIM 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<subscript>X</subscript> = 0.312; 6.3σ if the low-significance Ov and C v Kβ associations are considered), 3.9σ (z<subscript>X</subscript> = 0.237), and 3.8σ (<z<subscript>X</subscript>> = 0.133), respectively. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 769
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Astrophysical Journal
- Publication Type :
- Academic Journal
- Accession number :
- 90179178
- Full Text :
- https://doi.org/10.1088/0004-637X/769/2/90