The Impact of Shear on Disk Galaxy Star Formation Rates

Xena Fortune-Bashee, Jiayi Sun, 嘉懿 孙 and Jonathan C. Tan
{"title":"The Impact of Shear on Disk Galaxy Star Formation Rates","authors":"Xena Fortune-Bashee, Jiayi Sun, 嘉懿 孙 and Jonathan C. Tan","doi":"10.3847/2041-8213/ad91a3","DOIUrl":null,"url":null,"abstract":"Determining the physical processes that control galactic-scale star formation rates is essential for an improved understanding of galaxy evolution. The role of orbital shear is currently unclear, with some models expecting reduced star formation rates and efficiencies with increasing shear, e.g., if shear stabilizes gas against gravitational collapse, while others predicting enhanced rates, e.g., if shear-driven collisions between giant molecular clouds trigger star formation. Expanding on the analysis of 16 galaxies by C. Suwannajak et al., we assess the shear dependence of star formation efficiency (SFE) per orbital time (ϵorb) in 49 galaxies selected from the PHANGS-ALMA survey. In particular, we test a prediction of the shear-driven giant molecular cloud (GMC) collision model that ϵorb ∝ (1–0.7β), where , i.e., SFE per orbital time declines with decreasing shear. We fit the function ϵorb = ϵorb,0(1 − αCCβ) finding αCC ≃ 0.76 ± 0.16; an alternative fit with ϵorb normalized by the median value in each galaxy yields . These results are in good agreement with the prediction of the shear-driven GMC collision theory. We also examine the impact of a galactic bar on ϵorb finding a modest decrease in SFE in the presence of a bar, which can be attributed to lower rates of shear in these regions. We discuss the implications of our results for the GMC life cycle and environmental dependence of star formation activity.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"37 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Astrophysical Journal Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3847/2041-8213/ad91a3","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

Determining the physical processes that control galactic-scale star formation rates is essential for an improved understanding of galaxy evolution. The role of orbital shear is currently unclear, with some models expecting reduced star formation rates and efficiencies with increasing shear, e.g., if shear stabilizes gas against gravitational collapse, while others predicting enhanced rates, e.g., if shear-driven collisions between giant molecular clouds trigger star formation. Expanding on the analysis of 16 galaxies by C. Suwannajak et al., we assess the shear dependence of star formation efficiency (SFE) per orbital time (ϵorb) in 49 galaxies selected from the PHANGS-ALMA survey. In particular, we test a prediction of the shear-driven giant molecular cloud (GMC) collision model that ϵorb ∝ (1–0.7β), where , i.e., SFE per orbital time declines with decreasing shear. We fit the function ϵorb = ϵorb,0(1 − αCCβ) finding αCC ≃ 0.76 ± 0.16; an alternative fit with ϵorb normalized by the median value in each galaxy yields . These results are in good agreement with the prediction of the shear-driven GMC collision theory. We also examine the impact of a galactic bar on ϵorb finding a modest decrease in SFE in the presence of a bar, which can be attributed to lower rates of shear in these regions. We discuss the implications of our results for the GMC life cycle and environmental dependence of star formation activity.
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信