Physical Properties of H ii Regions in M51 from Spectroscopic Observations,Publications of the Astronomical Society of the Pacific

当前位置： X-MOL 学术 › PASP › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Physical Properties of H ii Regions in M51 from Spectroscopic Observations
Publications of the Astronomical Society of the Pacific ( IF 3.5 ) Pub Date : 2020-08-07 , DOI: 10.1088/1538-3873/ab9d92
Peng Wei _{1,

2,

3,

4} , Hu Zou _{3,

4} , Xu Kong ₅ , Xu Zhou _{3,

4} , Ning Hu _{5,

6} , Zesen Lin _{5,

6} , Yewei Mao ₇ , Lin Lin ₈ , Zhimin Zhou ₃ , Xiang Liu ₁ , Shuguo Ma _{1,

2} , Lu Ma ₁ , Tuhong Zhong ₁ , Fei Dang ₁ , Jiantao Sun ₁ , Xinkui Lin ₁

Affiliation

Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011, People's Republic of China
School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 101408, People's Republic of China
CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic of China
Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei 230026, People's Republic of China
School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, People's Republic of China
Center for Astrophysics, GuangZhou University, GuangZhou 510006, People's Republic of China
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, People's Republic of China

M51 and NGC 5195 is an interacting system that can be explored in great details with ground-based telescopes. The H II regions in M51 were observed using the 2.16 m telescope of the National Astronomical Observatories of the Chinese Academy of Sciences and the 6.5 m Multiple Mirror Telescope with spatial resolution of less than $\sim100$ pc. We obtain a total of 113 spectra across the galaxy and combine the literature data of Croxall et al. to derive a series of physical properties, including the gas-phase extinction, stellar population age, star formation rate (SFR) surface density, and oxygen abundance. The spatial distributions and radial profiles of these properties are investigated in order to study the characteristics of M51 and the clues to the formation and evolution of this galaxy. M51 presents a mild radial extinction gradient. The lower gas-phase extinction in the north spiral arms compared to the south arms are possibly caused by the past encounters with the companion galaxy of NGC 5195. A number of H II regions have the stellar age between 50 and 500 Myr, consistent with the recent interaction history by simulations in the literatures. The SFR surface density presents a mild radial gradient, which is ubiquitous in spiral galaxies. There is a negative metallicity gradient of $-0.08$ dex $R_{e}^{-1}$ in the disk region, which is also commonly found in many spiral galaxies. It is supported by the "inside-out" scenario of galaxy formation. We find a positive abundance gradient of 0.26 dex $R_{e}^{-1}$ in the inner region. There are possible reasons causing the positive gradient, including the freezing of the chemical enrichment due to the star-forming quenching in the bulge and the gas infall and dilution due to the pseudobulge growth and/or galactic interaction.

更新日期：2020-08-07

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南

全部期刊列表>>