{"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","day":"01","publisher":"American Astronomical Society","publication":"The Astrophysical Journal","main_file_link":[{"url":"https://doi.org/10.1086/428766","open_access":"1"}],"doi":"10.1086/428766","oa_version":"Published Version","volume":624,"oa":1,"page":"85-93","quality_controlled":"1","publication_identifier":{"issn":["0004-637X","1538-4357"]},"intvolume":"       624","extern":"1","date_created":"2024-09-06T09:48:59Z","type":"journal_article","title":"On detecting the X‐ray silhouette of a damped Lyα system","issue":"1","_id":"17761","date_updated":"2024-09-30T08:55:54Z","article_processing_charge":"No","abstract":[{"text":"We explore the possibility of resolving an image of a damped Lyα (DLA) system in absorption against an extended, diffuse, background X-ray source. Typical columns of neutral hydrogen in DLA systems are high enough to block out up to ~30% of the soft X-ray flux at an observed photon energy of 0.5 keV, and we find that ~1% of the area of extended X-ray sources at z ≳ 1 have their 0.5 keV flux reduced by at least 20% because of intervening DLA systems. We discuss the observability of such absorption and find that ≳300 photons per angular resolution element are required in the 0.3-8 keV band for its detection and in order to distinguish it from intrinsic surface brightness fluctuations. For the surface brightness of the currently known high-redshift extended X-ray sources, this requires an integration time of a few megaseconds on Chandra, if the maps are smoothed spatially to ≈2'' resolution. The exact required integration time depends on the DLA system's column density, metallicity, and, most strongly, its redshift. Current X-ray telescopes are likely to detect DLA systems with N < 10^22 cm^-2 only out to z ≈ 2.3. The availability of DLA systems with a suitably high column density for a silhouette detection is currently poorly known. We suggest that at low redshifts archival data of bright X-ray point sources may be useful in constraining the high-N end of the column density distribution. We briefly discuss an alternative strategy of searching for extended X-ray sources behind known DLA systems. Although with current X-ray telescopes the detections are challenging, they will be within the reach of a routine observation with a next generation X-ray telescope, such as the X-Ray Evolving Universe Spectrometer (XEUS) or Generation-X, and will deliver novel constraints on the nature of protogalaxies.","lang":"eng"}],"author":[{"full_name":"Dijkstra, Mark","last_name":"Dijkstra","first_name":"Mark"},{"id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36","full_name":"Haiman, Zoltán","last_name":"Haiman","first_name":"Zoltán"},{"last_name":"Scharf","first_name":"Caleb","full_name":"Scharf, Caleb"}],"language":[{"iso":"eng"}],"month":"05","article_type":"original","date_published":"2005-05-01T00:00:00Z","citation":{"chicago":"Dijkstra, Mark, Zoltán Haiman, and Caleb Scharf. “On Detecting the X‐ray Silhouette of a Damped Lyα System.” <i>The Astrophysical Journal</i>. American Astronomical Society, 2005. <a href=\"https://doi.org/10.1086/428766\">https://doi.org/10.1086/428766</a>.","short":"M. Dijkstra, Z. Haiman, C. Scharf, The Astrophysical Journal 624 (2005) 85–93.","ama":"Dijkstra M, Haiman Z, Scharf C. On detecting the X‐ray silhouette of a damped Lyα system. <i>The Astrophysical Journal</i>. 2005;624(1):85-93. doi:<a href=\"https://doi.org/10.1086/428766\">10.1086/428766</a>","mla":"Dijkstra, Mark, et al. “On Detecting the X‐ray Silhouette of a Damped Lyα System.” <i>The Astrophysical Journal</i>, vol. 624, no. 1, American Astronomical Society, 2005, pp. 85–93, doi:<a href=\"https://doi.org/10.1086/428766\">10.1086/428766</a>.","apa":"Dijkstra, M., Haiman, Z., &#38; Scharf, C. (2005). On detecting the X‐ray silhouette of a damped Lyα system. <i>The Astrophysical Journal</i>. American Astronomical Society. <a href=\"https://doi.org/10.1086/428766\">https://doi.org/10.1086/428766</a>","ieee":"M. Dijkstra, Z. Haiman, and C. Scharf, “On detecting the X‐ray silhouette of a damped Lyα system,” <i>The Astrophysical Journal</i>, vol. 624, no. 1. American Astronomical Society, pp. 85–93, 2005.","ista":"Dijkstra M, Haiman Z, Scharf C. 2005. On detecting the X‐ray silhouette of a damped Lyα system. The Astrophysical Journal. 624(1), 85–93."},"status":"public","publication_status":"published","year":"2005","scopus_import":"1"}