{"title":"ATLASGAL 星团中带有 H ii 区域的嵌入星团的物理特性","authors":"J. W. Zhou, Pavel Kroupa, Sami Dib","doi":"10.1088/1538-3873/ad6f44","DOIUrl":null,"url":null,"abstract":"Using the optimal sampling model, we synthesized the embedded clusters of ATLASGAL clumps with H<sc> ii</sc> regions (H<sc> ii</sc>-clumps). The 0.1 Myr isochrone was used to estimate the bolometric luminosity of each star in an embedded cluster, we also added the accretion luminosity of each star in the embedded cluster. The total bolometric luminosity of synthetic embedded clusters can well fit the observed bolometric luminosity of H<sc> ii</sc>-clumps. More realistically, we considered the age spread in the young star and protostar populations in embedded clusters of H<sc> ii</sc>-clumps by modeling both constant and time-varying star formation histories (SFHs). According to the age distribution of the stellar population, we distributed the appropriate isochrones to each star, and sorted out the fraction of stellar objects that are still protostars (Class 0 and Class I phases) to properly add their accretion luminosities. Compared to a constant SFH, burst-like and time-dependent SFHs can better fit the observational data. We found that as long as 20% of the stars within the embedded cluster are still accreting, the contribution of accretion luminosity will be significant to the total bolometric luminosity of low-mass H<sc> ii</sc>-clumps with mass log<sub>10</sub>(<italic toggle=\"yes\">M</italic>\n<sub>cl</sub>/<italic toggle=\"yes\">M</italic>\n<sub>⊙</sub>) < 2.8. Variations in the accretion rate, the SFE and the initial mass function and more physical processes like the external heating from H<sc> ii</sc> regions and the flaring from pre-main sequence stars and protostars need to be investigated to further explain the excess luminosity of low-mass H<sc> ii</sc>-clumps.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Physical Properties of Embedded Clusters in ATLASGAL Clumps with H ii Regions\",\"authors\":\"J. W. Zhou, Pavel Kroupa, Sami Dib\",\"doi\":\"10.1088/1538-3873/ad6f44\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Using the optimal sampling model, we synthesized the embedded clusters of ATLASGAL clumps with H<sc> ii</sc> regions (H<sc> ii</sc>-clumps). The 0.1 Myr isochrone was used to estimate the bolometric luminosity of each star in an embedded cluster, we also added the accretion luminosity of each star in the embedded cluster. The total bolometric luminosity of synthetic embedded clusters can well fit the observed bolometric luminosity of H<sc> ii</sc>-clumps. More realistically, we considered the age spread in the young star and protostar populations in embedded clusters of H<sc> ii</sc>-clumps by modeling both constant and time-varying star formation histories (SFHs). According to the age distribution of the stellar population, we distributed the appropriate isochrones to each star, and sorted out the fraction of stellar objects that are still protostars (Class 0 and Class I phases) to properly add their accretion luminosities. Compared to a constant SFH, burst-like and time-dependent SFHs can better fit the observational data. We found that as long as 20% of the stars within the embedded cluster are still accreting, the contribution of accretion luminosity will be significant to the total bolometric luminosity of low-mass H<sc> ii</sc>-clumps with mass log<sub>10</sub>(<italic toggle=\\\"yes\\\">M</italic>\\n<sub>cl</sub>/<italic toggle=\\\"yes\\\">M</italic>\\n<sub>⊙</sub>) < 2.8. Variations in the accretion rate, the SFE and the initial mass function and more physical processes like the external heating from H<sc> ii</sc> regions and the flaring from pre-main sequence stars and protostars need to be investigated to further explain the excess luminosity of low-mass H<sc> ii</sc>-clumps.\",\"PeriodicalId\":20820,\"journal\":{\"name\":\"Publications of the Astronomical Society of the Pacific\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-09-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Publications of the Astronomical Society of the Pacific\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1088/1538-3873/ad6f44\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Publications of the Astronomical Society of the Pacific","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1538-3873/ad6f44","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
利用最优采样模型,我们合成了带有H ii区域的ATLASGAL星团的嵌入星团(H i-clumps)。我们用0.1 Myr等时区来估算嵌入星团中每颗恒星的测光度,并加上嵌入星团中每颗恒星的吸积光度。合成嵌入星团的总测光度可以很好地拟合观测到的 H ii-clumps 的测光度。更为现实的是,我们通过模拟恒星形成史(SFH)和时变恒星形成史(SFH),考虑了 H ii-clumps 嵌入星团中年轻恒星和原恒星群的年龄分布。根据恒星群的年龄分布,我们为每颗恒星分配了适当的等时线,并对仍属于原恒星(0级和I级阶段)的恒星天体进行了分类,以适当增加它们的吸积光度。与恒定的SFH相比,类似爆发和随时间变化的SFH更适合观测数据。我们发现,只要嵌入星团中仍有20%的恒星在吸积,吸积光度对质量为log10(Mcl/M⊙) < 2.8的低质量H i-星团的总测光度的贡献就会很大。吸积率、SFE和初始质量函数的变化,以及更多的物理过程,如来自H ii区域的外部加热和来自前主序星和原恒星的闪烁,都需要进行研究,以进一步解释低质量H i-团块的过量光度。
Physical Properties of Embedded Clusters in ATLASGAL Clumps with H ii Regions
Using the optimal sampling model, we synthesized the embedded clusters of ATLASGAL clumps with H ii regions (H ii-clumps). The 0.1 Myr isochrone was used to estimate the bolometric luminosity of each star in an embedded cluster, we also added the accretion luminosity of each star in the embedded cluster. The total bolometric luminosity of synthetic embedded clusters can well fit the observed bolometric luminosity of H ii-clumps. More realistically, we considered the age spread in the young star and protostar populations in embedded clusters of H ii-clumps by modeling both constant and time-varying star formation histories (SFHs). According to the age distribution of the stellar population, we distributed the appropriate isochrones to each star, and sorted out the fraction of stellar objects that are still protostars (Class 0 and Class I phases) to properly add their accretion luminosities. Compared to a constant SFH, burst-like and time-dependent SFHs can better fit the observational data. We found that as long as 20% of the stars within the embedded cluster are still accreting, the contribution of accretion luminosity will be significant to the total bolometric luminosity of low-mass H ii-clumps with mass log10(Mcl/M⊙) < 2.8. Variations in the accretion rate, the SFE and the initial mass function and more physical processes like the external heating from H ii regions and the flaring from pre-main sequence stars and protostars need to be investigated to further explain the excess luminosity of low-mass H ii-clumps.
期刊介绍:
The Publications of the Astronomical Society of the Pacific (PASP), the technical journal of the Astronomical Society of the Pacific (ASP), has been published regularly since 1889, and is an integral part of the ASP''s mission to advance the science of astronomy and disseminate astronomical information. The journal provides an outlet for astronomical results of a scientific nature and serves to keep readers in touch with current astronomical research. It contains refereed research and instrumentation articles, invited and contributed reviews, tutorials, and dissertation summaries.