{"id":"https://openalex.org/W3204614816","doi":null,"title":"Classifying Seyfert galaxies with deep learning","display_name":"Classifying Seyfert galaxies with deep learning","publication_year":2021,"publication_date":"2021-09-24","ids":{"openalex":"https://openalex.org/W3204614816","mag":"3204614816"},"language":"en","primary_location":{"id":"pmh:oai:iris.uniroma1.it:11573/1609202","doi":null,"is_oa":true,"landing_page_url":"http://hdl.handle.net/11573/1609202","pdf_url":null,"source":{"id":"https://openalex.org/S4377196107","display_name":"IRIS Research product catalog (Sapienza University of Rome)","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":"cc-by-nd","license_id":"https://openalex.org/licenses/cc-by-nd","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"info:eu-repo/semantics/doctoralThesis"},"volume":null,"type":"dissertation","is_traditional":true,"indexed_in":[],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"http://hdl.handle.net/11573/1609202","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":null,"display_name":"Chen, Yen- Chen","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I4210122452","display_name":"International Center for Relativistic Astrophysics","ror":"https://ror.org/02jktn113","country_code":"IT","type":"facility","lineage":["https://openalex.org/I4210122452"]},{"id":"https://openalex.org/I861853513","display_name":"Sapienza University of Rome","ror":"https://ror.org/02be6w209","country_code":"IT","type":"education","lineage":["https://openalex.org/I861853513"]}],"countries":["IT"],"is_corresponding":true,"raw_author_name":"Chen, Yen- Chen","raw_affiliation_strings":["ICRA and Dipartimento di Fisica, Sapienza Universit\u00e0 di Roma, Piazzale Aldo Moro 5, I-00185 Rome, Italy","ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"ICRA and Dipartimento di Fisica, Sapienza Universit\u00e0 di Roma, Piazzale Aldo Moro 5, I-00185 Rome, Italy","institution_ids":["https://openalex.org/I861853513"]},{"raw_affiliation_string":"ICRANet, Piazza della Repubblica 10, I-65122 Pescara, Italy","institution_ids":["https://openalex.org/I4210122452"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":["https://openalex.org/I4210122452","https://openalex.org/I861853513"],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":4,"citation_normalized_percentile":null,"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/T10026","display_name":"Galaxies: Formation, Evolution, Phenomena","score":0.9940999746322632,"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/T10026","display_name":"Galaxies: Formation, Evolution, Phenomena","score":0.9940999746322632,"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/T10744","display_name":"Astrophysical Phenomena and Observations","score":0.00139999995008111,"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/T10039","display_name":"Stellar, planetary, and galactic studies","score":0.0006000000284984708,"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/seyfert-galaxies","display_name":"Seyfert galaxies","score":0.9789999723434448},{"id":"https://openalex.org/keywords/seyfert-2-galaxies","display_name":"Seyfert 2 galaxies","score":0.9760000109672546},{"id":"https://openalex.org/keywords/convolutional-neural-networks","display_name":"convolutional neural networks","score":0.8149999976158142},{"id":"https://openalex.org/keywords/supermassive-black-hole-mass","display_name":"supermassive black hole mass","score":0.9100000262260437},{"id":"https://openalex.org/keywords/host-galaxy-morphology","display_name":"host galaxy morphology","score":0.972000002861023},{"id":"https://openalex.org/keywords/bpt-diagram","display_name":"BPT diagram","score":0.824999988079071},{"id":"https://openalex.org/keywords/active-galactic-nuclei","display_name":"active galactic nuclei","score":0.7250000238418579},{"id":"https://openalex.org/keywords/visual-inspection-comparison","display_name":"visual inspection comparison","score":0.3100000023841858}],"concepts":[{"id":"https://openalex.org/C98444146","wikidata":"https://www.wikidata.org/wiki/Q318","display_name":"Galaxy","level":2,"score":0.8666584491729736},{"id":"https://openalex.org/C44870925","wikidata":"https://www.wikidata.org/wiki/Q37547","display_name":"Astrophysics","level":1,"score":0.8012511730194092},{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.7972164154052734},{"id":"https://openalex.org/C4839761","wikidata":"https://www.wikidata.org/wiki/Q212111","display_name":"Spectral line","level":2,"score":0.5004642009735107},{"id":"https://openalex.org/C12287442","wikidata":"https://www.wikidata.org/wiki/Q105902","display_name":"Luminosity","level":3,"score":0.500455379486084},{"id":"https://openalex.org/C68709404","wikidata":"https://www.wikidata.org/wiki/Q1134475","display_name":"Flux (metallurgy)","level":2,"score":0.4832044839859009},{"id":"https://openalex.org/C198352243","wikidata":"https://www.wikidata.org/wiki/Q37105","display_name":"Line (geometry)","level":2,"score":0.4770704507827759},{"id":"https://openalex.org/C173220165","wikidata":"https://www.wikidata.org/wiki/Q653711","display_name":"Balmer series","level":4,"score":0.4481913447380066},{"id":"https://openalex.org/C1276947","wikidata":"https://www.wikidata.org/wiki/Q333","display_name":"Astronomy","level":1,"score":0.30315613746643066},{"id":"https://openalex.org/C96141758","wikidata":"https://www.wikidata.org/wiki/Q216817","display_name":"Emission spectrum","level":3,"score":0.2950103282928467},{"id":"https://openalex.org/C2524010","wikidata":"https://www.wikidata.org/wiki/Q8087","display_name":"Geometry","level":1,"score":0.12669029831886292},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.086497962474823},{"id":"https://openalex.org/C191897082","wikidata":"https://www.wikidata.org/wiki/Q11467","display_name":"Metallurgy","level":1,"score":0.0},{"id":"https://openalex.org/C192562407","wikidata":"https://www.wikidata.org/wiki/Q228736","display_name":"Materials science","level":0,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"pmh:oai:iris.uniroma1.it:11573/1609202","doi":null,"is_oa":true,"landing_page_url":"http://hdl.handle.net/11573/1609202","pdf_url":null,"source":{"id":"https://openalex.org/S4377196107","display_name":"IRIS Research product catalog (Sapienza University of Rome)","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":"cc-by-nd","license_id":"https://openalex.org/licenses/cc-by-nd","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"info:eu-repo/semantics/doctoralThesis"}],"best_oa_location":{"id":"pmh:oai:iris.uniroma1.it:11573/1609202","doi":null,"is_oa":true,"landing_page_url":"http://hdl.handle.net/11573/1609202","pdf_url":null,"source":{"id":"https://openalex.org/S4377196107","display_name":"IRIS Research product catalog (Sapienza University of Rome)","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":"cc-by-nd","license_id":"https://openalex.org/licenses/cc-by-nd","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"info:eu-repo/semantics/doctoralThesis"},"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":48,"referenced_works":["https://openalex.org/W1843395103","https://openalex.org/W1967876247","https://openalex.org/W1969283683","https://openalex.org/W1999883030","https://openalex.org/W2000909045","https://openalex.org/W2001274855","https://openalex.org/W2024235708","https://openalex.org/W2029285143","https://openalex.org/W2031652044","https://openalex.org/W2041216883","https://openalex.org/W2048755753","https://openalex.org/W2054768286","https://openalex.org/W2081198904","https://openalex.org/W2083217178","https://openalex.org/W2083620124","https://openalex.org/W2084125113","https://openalex.org/W2085762475","https://openalex.org/W2086615899","https://openalex.org/W2089750221","https://openalex.org/W2092901033","https://openalex.org/W2093190121","https://openalex.org/W2093642860","https://openalex.org/W2097356275","https://openalex.org/W2114571933","https://openalex.org/W2117233176","https://openalex.org/W2122341519","https://openalex.org/W2124271958","https://openalex.org/W2124999166","https://openalex.org/W2151133271","https://openalex.org/W2157917411","https://openalex.org/W2163212281","https://openalex.org/W2163605009","https://openalex.org/W2198074945","https://openalex.org/W2563171474","https://openalex.org/W2773387254","https://openalex.org/W2801225189","https://openalex.org/W2885274016","https://openalex.org/W2921922690","https://openalex.org/W2936634966","https://openalex.org/W2950175496","https://openalex.org/W2965541175","https://openalex.org/W2969767295","https://openalex.org/W2984041077","https://openalex.org/W3098784892","https://openalex.org/W3104715349","https://openalex.org/W3122317788","https://openalex.org/W3124191121","https://openalex.org/W3135097080"],"related_works":["https://openalex.org/W4401245892","https://openalex.org/W7208815208","https://openalex.org/W4392915781","https://openalex.org/W4387080731","https://openalex.org/W2122341519","https://openalex.org/W1982064069","https://openalex.org/W7098528055","https://openalex.org/W1969950777","https://openalex.org/W2310186107","https://openalex.org/W4213010232"],"abstract_inverted_index":{"Seyfert":[0,92,105,109,118,121,137,147,159,175,191,195,218,260,267,281,324,340,353,391,407,413,420,423,443,458,468],"galaxies":[1,93,107,123,342,393,425],"have":[2,356,372,426,456,462],"several":[3,78],"subclasses":[4],"according":[5],"to":[6,87,103,162,244,251,412,449],"observation":[7],"features":[8],"of":[9,54,66,90,128,166,173,208,216,255,258,321,332,338,384,389,405],"their":[10,431],"optical":[11],"spectra.":[12],"Traditional":[13],"classification":[14,62,80],"is":[15,24,40,59,69,211,394],"usually":[16],"visual":[17,38,144,308],"inspection":[18,39,145],"or":[19],"using":[20],"a":[21,27,43,84,96,101,151,186],"quantity":[22,44],"that":[23,180,287,329,368,419,461],"defined":[25],"as":[26,100,185],"flux":[28,47,247],"ratio":[29,48],"between":[30],"the":[31,52,60,91,157,164,174,203,209,213,223,241,253,265,279,312,322,330,351,364,369,382,385,390,402,437,451],"Balmer":[32],"line":[33,56,215,227,246,249],"and":[34,42,75,120,169,231,248,301,422,465,475],"forbidden":[35],"line.":[36],"However,":[37],"time-consuming":[41],"derived":[45],"from":[46,108],"does":[49],"not":[50],"reflect":[51],"information":[53],"emission":[55,214,226,256],"shape":[57],"which":[58,140],"original":[61],"feature.":[63],"One":[64],"algorithm":[65],"deep":[67],"learning":[68],"called":[70],"Convolution":[71],"Neural":[72],"Network":[73],"(CNN)":[74],"has":[76,270],"shown":[77],"successful":[79],"results.":[81],"We":[82,112,154,221,239,263,310,327,349,400,454],"use":[83,156,240],"CNN":[85,98],"model":[86,99,115,132,168,182,289],"classify":[88],"spectra":[89,193,197,448,464],"by":[94,143,234,307,345,396],"building":[95],"1-dimension":[97],"classifier":[102,187],"distinguish":[104],"1.9":[106,119,138,160,192,219,261,268,282,325,341,354,392,408,421,444,459,469],"2":[110,122,148,196,236,414,424],"galaxies.":[111,220,262,415],"find":[113,264,328,350,381,401,466],"our":[114,167,181,217,259,288,339,406,442],"can":[116,183,290],"recognize":[117],"correctly":[124],"with":[125,294,441],"an":[126,135,199,271],"accuracy":[127],"over":[129],"80%.":[130],"Our":[131],"picks":[133],"out":[134,190,292],"additional":[136],"sample":[139,161,269],"was":[141],"missed":[142,306],"among":[146,194],"samples":[149,355,409],"in":[150,198,430,473],"short":[152],"time.":[153],"also":[155],"new":[158],"improve":[163],"performance":[165],"obtain":[170],"91%":[171],"precision":[172],"1.9.":[176],"This":[177,284,416],"result":[178,285,417],"indicates":[179,286,418],"act":[184],"for":[188,202,446],"picking":[189],"efficient":[200],"way":[201],"future.":[204],"The":[205],"second":[206],"part":[207],"thesis":[210],"about":[212],"decompose":[222],"H":[224,275,298,477],"alpha":[225,276,299,478],"into":[228],"narrow":[229],"component":[230,233,277,300],"broad":[232,274,297,476],"fitting":[235,242],"Gaussian":[237],"components.":[238],"results":[243,366],"derive":[245],"width":[250],"investigate":[252,311,450],"properties":[254],"lines":[257],"641":[266],"averagely":[272],"luminous":[273],"than":[278],"656":[280],"sample.":[283],"pick":[291],"sources":[293,303,445,460,470],"relatively":[295],"weak":[296],"these":[302],"are":[304,343,410],"sometimes":[305],"inspection.":[309],"black":[313,334,359],"hole":[314,335,360],"mass,":[315],"host":[316,377,386],"galaxy":[317,378,387],"morphology,":[318],"BPT":[319,403],"diagram":[320],"two":[323,352,370],"samples.":[326],"distributions":[331,362,371,404],"supermassive":[333],"(SMBH)":[336],"mass":[337,361],"dominated":[344],"10^7":[346],"solar":[347],"mass.":[348],"slightly":[357],"different":[358],"but":[363],"t-test":[365],"indicate":[367],"similar":[373,411,427],"mean":[374],"values.":[375],"From":[376],"results,":[379],"we":[380,435],"distribution":[383],"morphology":[388],"dominant":[395],"large":[397],"bulge":[398],"galaxy.":[399],"ionization":[428],"levels":[429],"narrow-line":[432],"region.":[433],"Besides,":[434],"cross-search":[436],"Strip":[438],"82":[439],"survey":[440],"multiple":[447,463],"possible":[452],"variability.":[453],"only":[455],"13":[457,467],"show":[471],"variation":[472],"continuum":[474],"component.":[479]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2023,"cited_by_count":1},{"year":2022,"cited_by_count":2}],"updated_date":"2026-11-04T10:54:05.112534","created_date":"2021-10-11T00:00:00"}