Diffuse Ionized Gas in the Anticenter of the Milky Way
Using data from the Large Area Multi-Object fiber Spectroscopic Telescope Medium-Resolution Spectroscopic Survey of Nebulae, we create a sample of 17,821 diffuse ionized gas spectra in the anticenter region of the Milky Way by excluding fibers in the directions of H ii regions and supernova remnants...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2025-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ad9b8e |
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| author | Shiming Wen Wei Zhang Lin Ma Yunning Zhao Man I. Lam Chaojian Wu Juanjuan Ren Jianjun Chen Yuzhong Wu Guozhen Hu Yonghui Hou Yongheng Zhao Hong Wu |
| author_facet | Shiming Wen Wei Zhang Lin Ma Yunning Zhao Man I. Lam Chaojian Wu Juanjuan Ren Jianjun Chen Yuzhong Wu Guozhen Hu Yonghui Hou Yongheng Zhao Hong Wu |
| author_sort | Shiming Wen |
| collection | DOAJ |
| description | Using data from the Large Area Multi-Object fiber Spectroscopic Telescope Medium-Resolution Spectroscopic Survey of Nebulae, we create a sample of 17,821 diffuse ionized gas spectra in the anticenter region of the Milky Way by excluding fibers in the directions of H ii regions and supernova remnants. We then analyze the radial and vertical distributions of three line ratios ([N ii ]/H α , [S ii ]/H α , and [S ii ]/[N ii ]), as well as the oxygen abundance. [N ii ]/H α and [S ii ]/H α do not exhibit a consistent, monotonic decrease with increasing Galactocentric distance ( R _gal ). Instead, they show enhancement within the interarm region, positioned between the Local Arm and the Perseus Arm. [S ii ]/[N ii ] has a radial gradient of 0.1415 ± 0.0646 kpc ^−1 for the inner disk (8.34 < R _gal < 9.65 kpc) and remains nearly flat for the outer disk ( R _gal > 9.65 kpc). In the vertical direction, [N ii ]/H α , [S ii ]/H α , and [S ii ]/[N ii ] increase with increasing Galactic disk height (∣ z ∣) in both southern and northern disks. Based on the N2S2H α method, which combines [S ii ]/[N ii ] and [N ii ]/H α , we estimate the oxygen abundance. The oxygen abundance exhibits a consistent radial gradient with R _gal , featuring a slope of −0.0559 ± 0.0209 dex kpc ^−1 for the inner disk and a similar slope of −0.0429 ± 0.0599 dex kpc ^−1 for the outer disk. A single linear fitting to the entire disk yields a slope of −0.0317 ± 0.0124 dex kpc ^−1 . In the vertical direction, the oxygen abundance decreases with increasing ∣ z ∣ in both southern and northern disks. |
| format | Article |
| id | doaj-art-75126b9010624d1fb18d83895c6f339c |
| institution | Kabale University |
| issn | 1538-3881 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj-art-75126b9010624d1fb18d83895c6f339c2025-01-27T11:24:58ZengIOP PublishingThe Astronomical Journal1538-38812025-01-0116929510.3847/1538-3881/ad9b8eDiffuse Ionized Gas in the Anticenter of the Milky WayShiming Wen0https://orcid.org/0009-0008-1361-4825Wei Zhang1https://orcid.org/0000-0002-1783-957XLin Ma2Yunning Zhao3https://orcid.org/0009-0000-6954-9825Man I. Lam4Chaojian Wu5Juanjuan Ren6https://orcid.org/0000-0003-3243-464XJianjun Chen7Yuzhong Wu8Guozhen Hu9https://orcid.org/0000-0003-1828-5318Yonghui Hou10Yongheng Zhao11Hong Wu12CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cnCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cnCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cn; The Key Laboratory of Cosmic Rays (Tibet University) , Ministry of Education, Lhasa 850000, Tibet, People’s Republic of China; School of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cn; School of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaCAS Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cnCAS Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaCAS Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cnCollege of Physics, Hebei Normal University , 20 South Erhuan Road, Shijiazhuang 050024, People’s Republic of ChinaSchool of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of China; Nanjing Institute of Astronomical Optics ,& Technology, National Astronomical Observatories, Chinese Academy of Sciences, Nanjing 210042, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cn; School of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaCAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences , Beijing 100101, People’s Republic of China ; xtwfn@bao.ac.cn; School of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaUsing data from the Large Area Multi-Object fiber Spectroscopic Telescope Medium-Resolution Spectroscopic Survey of Nebulae, we create a sample of 17,821 diffuse ionized gas spectra in the anticenter region of the Milky Way by excluding fibers in the directions of H ii regions and supernova remnants. We then analyze the radial and vertical distributions of three line ratios ([N ii ]/H α , [S ii ]/H α , and [S ii ]/[N ii ]), as well as the oxygen abundance. [N ii ]/H α and [S ii ]/H α do not exhibit a consistent, monotonic decrease with increasing Galactocentric distance ( R _gal ). Instead, they show enhancement within the interarm region, positioned between the Local Arm and the Perseus Arm. [S ii ]/[N ii ] has a radial gradient of 0.1415 ± 0.0646 kpc ^−1 for the inner disk (8.34 < R _gal < 9.65 kpc) and remains nearly flat for the outer disk ( R _gal > 9.65 kpc). In the vertical direction, [N ii ]/H α , [S ii ]/H α , and [S ii ]/[N ii ] increase with increasing Galactic disk height (∣ z ∣) in both southern and northern disks. Based on the N2S2H α method, which combines [S ii ]/[N ii ] and [N ii ]/H α , we estimate the oxygen abundance. The oxygen abundance exhibits a consistent radial gradient with R _gal , featuring a slope of −0.0559 ± 0.0209 dex kpc ^−1 for the inner disk and a similar slope of −0.0429 ± 0.0599 dex kpc ^−1 for the outer disk. A single linear fitting to the entire disk yields a slope of −0.0317 ± 0.0124 dex kpc ^−1 . In the vertical direction, the oxygen abundance decreases with increasing ∣ z ∣ in both southern and northern disks.https://doi.org/10.3847/1538-3881/ad9b8eInterstellar line emissionMetallicityWarm ionized medium |
| spellingShingle | Shiming Wen Wei Zhang Lin Ma Yunning Zhao Man I. Lam Chaojian Wu Juanjuan Ren Jianjun Chen Yuzhong Wu Guozhen Hu Yonghui Hou Yongheng Zhao Hong Wu Diffuse Ionized Gas in the Anticenter of the Milky Way The Astronomical Journal Interstellar line emission Metallicity Warm ionized medium |
| title | Diffuse Ionized Gas in the Anticenter of the Milky Way |
| title_full | Diffuse Ionized Gas in the Anticenter of the Milky Way |
| title_fullStr | Diffuse Ionized Gas in the Anticenter of the Milky Way |
| title_full_unstemmed | Diffuse Ionized Gas in the Anticenter of the Milky Way |
| title_short | Diffuse Ionized Gas in the Anticenter of the Milky Way |
| title_sort | diffuse ionized gas in the anticenter of the milky way |
| topic | Interstellar line emission Metallicity Warm ionized medium |
| url | https://doi.org/10.3847/1538-3881/ad9b8e |
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