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arXiv 2310.08482astro-ph.GA
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DIISC-III:邻近星系恒星盘生长的特征

DIISC-III: Signatures of Stellar Disk Growth in Nearby Galaxies

Mansi Padave, Sanchayeeta Borthakur, Hansung B. Gim, David Thilker, Rolf A. Jansen, Jacqueline Monckiewicz, Robert C. Kennicutt, Guinevere Kauffmann, Andrew J. … 展开作者

Mansi Padave, Sanchayeeta Borthakur, Hansung B. Gim, David Thilker, Rolf A. Jansen, Jacqueline Monckiewicz, Robert C. Kennicutt, Guinevere Kauffmann, Andrew J. Fox, Emmanuel Momjian, Timothy Heckman

AI总结:

本研究基于DIISC巡天数据,通过分析14个邻近星系的sSFR径向分布和$Δ_{sSFR}$/sSFR,发现HI气体比例与盘增长相关,且孤立环境中星系周介质HI受抑制,但不影响恒星形成方向。

摘要:

我们作为“解密星际介质、恒星与星系周介质之间的相互作用”(DIISC)巡天的一部分,探索了14个邻近旋涡星系中恒星盘的增长。我们研究了比恒星形成率(sSFR)的径向分布,并考察了盘的外部和内部sSFR之差($Δ_{sSFR}~={\ m sSFR}_{out}-{\ m sSFR}_{in}$)与总sSFR之比,即$Δ_{sSFR}$/sSFR,以量化盘的增长。我们发现$Δ_{sSFR}$/sSFR与HI气体比例显示出轻微的相关性,Spearman's $ρ=0.30$,表明在HI气体比例高的星系盘中,恒星形成和盘增长可能向外进行。星系中的HI气体比例和$Δ_{sSFR}$/sSFR也随着到最近L$_\u2217$邻居的距离增加而增加,这表明星系在孤立环境中可能维持其星际介质中的冷气体,并表现出由内而外的增长。然而,在孤立环境中,星系周介质中的HI含量(通过Ly$α$等效宽度(W$_{Lyα}$)超出量探测)被观察到受到抑制,这从W$_{Lyα}$超出量与到第5个最近L$_\u2217$邻居的距离之间的强反相关性(Spearman's $ρ=-0.62$)可以看出。正如预期,W$_{Lyα}$在星系团星系中也受到抑制。我们发现探测到的CGM吸收体的W$_{Lyα}$超出量与$Δ_{sSFR}$/sSFR之间没有关系,这意味着星系周HI气体的增强和抑制并不影响恒星形成在星系盘中的进行方向,反之亦然。

英文摘要:

We explore the growth of the stellar disks in 14 nearby spiral galaxies as part of the Deciphering the Interplay between the Interstellar medium, Stars, and the Circumgalactic medium (DIISC) survey. We study the radial distribution of specific star formation rates (sSFR) and investigate the ratio of the difference in the outer and inner sSFR ($Δ_{sSFR}~={\rm sSFR}_{out}-{\rm sSFR}_{in}$) of the disk and the total sSFR, $Δ_{sSFR}$/sSFR to quantify disk growth. We find $Δ_{sSFR}$/sSFR and the HI gas fraction to show a mild correlation of Spearman's $ρ=0.30$, indicating that star formation and disk growth are likely to proceed outward in galactic disks with high HI gas fractions. The HI gas fractions and $Δ_{sSFR}$/sSFR of the galaxies also increase with the distance to the nearest L$_\star$ neighbor, suggesting that galaxies are likely to sustain their ISM cold gas and exhibit inside-out growth in isolated environments. However, the HI content in their circumgalactic medium, probed by the Ly$α$ equivalent width (W$_{Lyα}$) excess, is observed to be suppressed in isolated environments, apparent from the strong anti-correlation between the W$_{Lyα}$ excess and the distance to the 5$^{\rm th}$ nearest L$_\star$ neighbor (Spearman's $ρ=-0.62$). As expected, W$_{Lyα}$ is also found to be suppressed in cluster galaxies. We find no relation between the W$_{Lyα}$ excess of the detected CGM absorber and $Δ_{sSFR}$/sSFR implying that the enhancement and suppression of the circumgalactic HI gas does not affect the direction in which star formation proceeds in a galactic disk or vice-versa.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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