{"id":"https://openalex.org/W7225408035","doi":"https://doi.org/10.14288/1.0457111","title":"Search for 21cm absorption systems with CHIME","display_name":"Search for 21cm absorption systems with CHIME","publication_year":2026,"publication_date":"2026-11-06","ids":{"openalex":"https://openalex.org/W7225408035","doi":"https://doi.org/10.14288/1.0457111"},"language":"en","primary_location":{"id":"doi:10.14288/1.0457111","doi":"https://doi.org/10.14288/1.0457111","is_oa":true,"landing_page_url":"https://doi.org/10.14288/1.0457111","pdf_url":null,"source":{"id":"https://openalex.org/S7407053062","display_name":"Open Collections","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"article-journal"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["datacite"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://doi.org/10.14288/1.0457111","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5054140819","display_name":"Arash Mirhosseini","orcid":"https://orcid.org/0000-0002-2626-5985","observed_orcids":["https://orcid.org/0000-0002-2626-5985"]},"institutions":[],"countries":[],"is_corresponding":true,"raw_author_name":"Mirhosseini, Arash","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":["https://openalex.org/A5054140819"],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":{"value":0.0,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T12450","display_name":"Radio Astronomy Observations and Technology","score":0.9326000213623047,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T12450","display_name":"Radio Astronomy Observations and Technology","score":0.9326000213623047,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10026","display_name":"Galaxies: Formation, Evolution, Phenomena","score":0.054499998688697815,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10477","display_name":"Astrophysics and Star Formation Studies","score":0.0044999998062849045,"subfield":{"id":"https://openalex.org/subfields/3103","display_name":"Astronomy and Astrophysics"},"field":{"id":"https://openalex.org/fields/31","display_name":"Physics and Astronomy"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/hi-21-cm-absorption","display_name":"21 cm absorption","score":0.9190000295639038},{"id":"https://openalex.org/keywords/neutral-hydrogen","display_name":"neutral hydrogen","score":0.7979999780654907},{"id":"https://openalex.org/keywords/high-redshift-absorbers","display_name":"high-redshift absorbers","score":0.8029999732971191},{"id":"https://openalex.org/keywords/chimes","display_name":"chimes","score":0.6679999828338623},{"id":"https://openalex.org/keywords/blind-survey","display_name":"blind survey","score":0.8209999799728394},{"id":"https://openalex.org/keywords/data-pipelines","display_name":"data pipelines","score":0.6460000276565552},{"id":"https://openalex.org/keywords/cold-gas","display_name":"cold gas","score":0.597000002861023},{"id":"https://openalex.org/keywords/intensity-mapping","display_name":"intensity mapping","score":0.5600000023841858}],"concepts":[{"id":"https://openalex.org/C33024259","wikidata":"https://www.wikidata.org/wiki/Q76250","display_name":"Redshift","level":3,"score":0.7321000099182129},{"id":"https://openalex.org/C125287762","wikidata":"https://www.wikidata.org/wiki/Q1758948","display_name":"Absorption (acoustics)","level":2,"score":0.5708000063896179},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.5145000219345093},{"id":"https://openalex.org/C44870925","wikidata":"https://www.wikidata.org/wiki/Q37547","display_name":"Astrophysics","level":1,"score":0.5123999714851379},{"id":"https://openalex.org/C120665830","wikidata":"https://www.wikidata.org/wiki/Q14620","display_name":"Optics","level":1,"score":0.47839999198913574},{"id":"https://openalex.org/C119824511","wikidata":"https://www.wikidata.org/wiki/Q13553575","display_name":"Absorption spectroscopy","level":2,"score":0.37310001254081726},{"id":"https://openalex.org/C1276947","wikidata":"https://www.wikidata.org/wiki/Q333","display_name":"Astronomy","level":1,"score":0.36899998784065247},{"id":"https://openalex.org/C161813005","wikidata":"https://www.wikidata.org/wiki/Q184356","display_name":"Radio telescope","level":2,"score":0.3504999876022339},{"id":"https://openalex.org/C2780848835","wikidata":"https://www.wikidata.org/wiki/Q4213","display_name":"Telescope","level":2,"score":0.3375000059604645},{"id":"https://openalex.org/C62649853","wikidata":"https://www.wikidata.org/wiki/Q199687","display_name":"Remote sensing","level":1,"score":0.325300008058548},{"id":"https://openalex.org/C60056205","wikidata":"https://www.wikidata.org/wiki/Q691914","display_name":"Opacity","level":2,"score":0.3230000138282776},{"id":"https://openalex.org/C164918935","wikidata":"https://www.wikidata.org/wiki/Q1406191","display_name":"Hydrogen line","level":3,"score":0.32190001010894775},{"id":"https://openalex.org/C166689943","wikidata":"https://www.wikidata.org/wiki/Q850283","display_name":"Interferometry","level":2,"score":0.3037000000476837},{"id":"https://openalex.org/C43521106","wikidata":"https://www.wikidata.org/wiki/Q2165493","display_name":"Pipeline (software)","level":2,"score":0.2858000099658966},{"id":"https://openalex.org/C4839761","wikidata":"https://www.wikidata.org/wiki/Q212111","display_name":"Spectral line","level":2,"score":0.2827000021934509},{"id":"https://openalex.org/C192562407","wikidata":"https://www.wikidata.org/wiki/Q228736","display_name":"Materials science","level":0,"score":0.2653999924659729},{"id":"https://openalex.org/C73329638","wikidata":"https://www.wikidata.org/wiki/Q527","display_name":"Sky","level":2,"score":0.2651999890804291},{"id":"https://openalex.org/C512968161","wikidata":"https://www.wikidata.org/wiki/Q556","display_name":"Hydrogen","level":2,"score":0.26109999418258667},{"id":"https://openalex.org/C96141758","wikidata":"https://www.wikidata.org/wiki/Q216817","display_name":"Emission spectrum","level":3,"score":0.2596000134944916},{"id":"https://openalex.org/C204323151","wikidata":"https://www.wikidata.org/wiki/Q905424","display_name":"Range (aeronautics)","level":2,"score":0.25940001010894775},{"id":"https://openalex.org/C98444146","wikidata":"https://www.wikidata.org/wiki/Q318","display_name":"Galaxy","level":2,"score":0.2581000030040741}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.14288/1.0457111","doi":"https://doi.org/10.14288/1.0457111","is_oa":true,"landing_page_url":"https://doi.org/10.14288/1.0457111","pdf_url":null,"source":{"id":"https://openalex.org/S7407053062","display_name":"Open Collections","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"article-journal"}],"best_oa_location":{"id":"doi:10.14288/1.0457111","doi":"https://doi.org/10.14288/1.0457111","is_oa":true,"landing_page_url":"https://doi.org/10.14288/1.0457111","pdf_url":null,"source":{"id":"https://openalex.org/S7407053062","display_name":"Open Collections","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"article-journal"},"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":0,"referenced_works":[],"related_works":["https://openalex.org/W7130420321","https://openalex.org/W2605748475","https://openalex.org/W2185793821","https://openalex.org/W188798891","https://openalex.org/W140660107","https://openalex.org/W7168300409","https://openalex.org/W2033003110","https://openalex.org/W2105897131","https://openalex.org/W2995791058","https://openalex.org/W1847272642"],"abstract_inverted_index":{"The":[0,191,294],"21":[1,47,51,68,86,134,167,227,280,300,339],"cm":[2,48,52,69,87,135,168,228,281,301,340],"hyperfine":[3],"transition":[4],"of":[5,12,26,40,61,84,109,115,159,185,195,203,214,219,241,296,323,330,337],"neutral":[6,27],"hydrogen":[7],"is":[8,58],"a":[9,19,24,33,130,146,183,224,261,304,320,343],"powerful":[10],"probe":[11],"cold":[13,30],"gas":[14,31],"across":[15],"cosmic":[16],"time.":[17],"When":[18],"radio":[20,117,148],"source":[21,43],"lies":[22],"behind":[23],"cloud":[25],"hydrogen,":[28],"the":[29,38,41,45,55,62,65,81,107,113,120,126,139,156,166,199,238,258,265,311,324,328,335],"imprints":[32],"characteristic":[34],"absorption":[35,56,70,136,269],"feature":[36,57],"in":[37,272,310],"spectrum":[39],"background":[42],"at":[44,73,89,119,151,230,245,283,314],"redshifted":[46],"frequency.":[49],"Unlike":[50],"emission":[53],"line,":[54],"detectable":[59],"independently":[60],"distance":[63],"to":[64,103,155,176,332],"absorber,":[66],"making":[67],"equally":[71],"sensitive":[72],"low":[74],"and":[75,112,181,193,290],"high":[76],"redshift.":[77],"Despite":[78],"this":[79,104,196,204],"advantage,":[80],"known":[82,101,251,312],"sample":[83,313],"extragalactic":[85],"absorbers":[88,253,282,302,341],"redshifts":[90],"z":[91,162,231,246,284,287,291,315],">":[92,247,316],"1":[93],"has":[94],"remained":[95],"small:":[96],"only":[97,237],"42":[98],"systems":[99],"were":[100,254],"prior":[102],"work,":[105],"reflecting":[106],"limitations":[108],"targeted":[110],"surveys":[111],"scarcity":[114],"suitable":[116],"facilities":[118],"relevant":[121],"frequencies.":[122],"This":[123],"thesis":[124],"presents":[125],"CHIME":[127,220,273,331],"Absorber":[128,221,266],"Project:":[129],"blind":[131,209,345],"survey":[132,210],"for":[133,165,188],"conducted":[137],"with":[138],"Canadian":[140],"Hydrogen":[141],"Intensity":[142],"Mapping":[143],"Experiment":[144],"(CHIME),":[145],"transit":[147],"telescope":[149],"operating":[150],"400\u2013800":[152],"MHz,":[153],"corresponding":[154],"redshift":[157],"range":[158],"0.78":[160],"<":[161,163],"2.55":[164],"line.":[169],"An":[170],"offline":[171],"processing":[172],"pipeline":[173,197],"was":[174],"developed":[175],"process":[177],"raw":[178],"archived":[179],"data":[180],"return":[182],"list":[184],"absorber":[186,229,244],"candidates":[187,270],"visual":[189],"inspection.":[190],"design":[192],"implementation":[194],"represent":[198],"primary":[200],"technical":[201],"contribution":[202],"thesis.":[205],"A":[206],"pilot":[207],"spectrally":[208],"along":[211],"202":[212],"lines":[213],"sight,":[215],"using":[216,264],"four":[217,298],"months":[218],"data,":[222,276,326],"yielded":[223],"new":[225,279,299],"associated":[226,243],"=":[232,285,288,292],"2.327":[233],"toward":[234],"NVSS":[235],"J164725-+375218,":[236],"fifth":[239],"detection":[240],"an":[242],"2.":[248],"Two":[249],"previously":[250],"intervening":[252],"also":[255],"recovered,":[256],"validating":[257],"pipeline.":[259],"Moreover,":[260],"follow-up":[262],"search":[263],"pipeline,":[267],"targeting":[268],"identified":[271],"intensity":[274],"mapping":[275],"confirmed":[277],"three":[278],"1.1235,":[286],"1.1577,":[289],"1.1747.":[293],"discovery":[295],"these":[297],"represents":[303],"roughly":[305],"10":[306],"per":[307],"cent":[308],"increase":[309],"1,":[317],"obtained":[318],"from":[319],"small":[321],"fraction":[322],"available":[325],"demonstrating":[327],"potential":[329],"substantially":[333],"expand":[334],"census":[336],"high-redshift":[338],"through":[342],"fully":[344],"survey.":[346]},"counts_by_year":[],"updated_date":"2026-11-08T12:12:28.789561","created_date":"2026-11-07T00:00:00"}
