Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae
“Ly α nebulae” are immense (∼100 kpc) glowing gas clouds located in the distant universe, and the origin of their extended Ly α emission remains a mystery. Mapping their polarization offers critical insights, but imaging polarimetry to date has revealed polarization patterns that are difficult to in...
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2025-01-01
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| Online Access: | https://doi.org/10.3847/1538-4357/adef52 |
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| author | Eunchong Kim Yujin Yang Sung-Joon Park Ann Zabludoff Paul Smith Myung Gyoon Lee Woong-Seob Jeong Buell Jannuzi Narae Hwang Byeong-Gon Park |
| author_facet | Eunchong Kim Yujin Yang Sung-Joon Park Ann Zabludoff Paul Smith Myung Gyoon Lee Woong-Seob Jeong Buell Jannuzi Narae Hwang Byeong-Gon Park |
| author_sort | Eunchong Kim |
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| description | “Ly α nebulae” are immense (∼100 kpc) glowing gas clouds located in the distant universe, and the origin of their extended Ly α emission remains a mystery. Mapping their polarization offers critical insights, but imaging polarimetry to date has revealed polarization patterns that are difficult to interpret due to differences in the types and spatial configurations of their embedded sources. In this study, we more than double the sample size of polarization observations by targeting four additional Ly α nebulae: 4C41.17, SSA22-Sb3-LAB1, JACKPOT, and MAMMOTH-1, all of which host active galactic nuclei (AGN), from radio-loud to radio-quiet to type-I to type-II. Significant polarization is detected in three of these four nebulae, with polarization vectors distributed across the extended Ly α -emitting gas. In the two Ly α nebulae hosting radio-loud AGN, the polarization vectors exhibit a preferential alignment perpendicular to the radio jet direction, suggesting a scattering origin related to AGN outflows. In 4C41.17, JACKPOT, and MAMMOTH-1 (3/4 cases), the polarization strength shows a possible trend of increasing with radius. While the spatial patterns are complex and most large-radius measurements are upper limits, our results—together with previous work on three other targets—support the idea that scattering plays a key role in shaping the Ly α emission from these nebulae. Full interpretation requires direct comparison of these observations to radiative transfer models over a wide range of parameter space. |
| format | Article |
| id | doaj-art-fe97d6cec3044beebc104f556ae72546 |
| institution | Kabale University |
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| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-fe97d6cec3044beebc104f556ae725462025-08-20T04:03:25ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01989221110.3847/1538-4357/adef52Using Polarization to Uncover the Lyα Emission Mechanism in Lyα NebulaeEunchong Kim0https://orcid.org/0000-0002-3370-187XYujin Yang1https://orcid.org/0000-0003-3078-2763Sung-Joon Park2Ann Zabludoff3https://orcid.org/0000-0001-6047-8469Paul Smith4https://orcid.org/0000-0002-5083-3663Myung Gyoon Lee5https://orcid.org/0000-0003-2713-6744Woong-Seob Jeong6https://orcid.org/0000-0002-2770-808XBuell Jannuzi7Narae Hwang8https://orcid.org/0000-0002-2013-1273Byeong-Gon Park9https://orcid.org/0000-0002-6982-7722International Gemini Observatory/NSF NOIRLab , 670 N. A’ohoku Place, Hilo, HI 96720, USA; Korea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaSteward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USASteward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USADepartment of Physics and Astronomy, Seoul National University , Gwanak-gu, Seoul 88226, Republic of KoreaKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaSteward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USAKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea“Ly α nebulae” are immense (∼100 kpc) glowing gas clouds located in the distant universe, and the origin of their extended Ly α emission remains a mystery. Mapping their polarization offers critical insights, but imaging polarimetry to date has revealed polarization patterns that are difficult to interpret due to differences in the types and spatial configurations of their embedded sources. In this study, we more than double the sample size of polarization observations by targeting four additional Ly α nebulae: 4C41.17, SSA22-Sb3-LAB1, JACKPOT, and MAMMOTH-1, all of which host active galactic nuclei (AGN), from radio-loud to radio-quiet to type-I to type-II. Significant polarization is detected in three of these four nebulae, with polarization vectors distributed across the extended Ly α -emitting gas. In the two Ly α nebulae hosting radio-loud AGN, the polarization vectors exhibit a preferential alignment perpendicular to the radio jet direction, suggesting a scattering origin related to AGN outflows. In 4C41.17, JACKPOT, and MAMMOTH-1 (3/4 cases), the polarization strength shows a possible trend of increasing with radius. While the spatial patterns are complex and most large-radius measurements are upper limits, our results—together with previous work on three other targets—support the idea that scattering plays a key role in shaping the Ly α emission from these nebulae. Full interpretation requires direct comparison of these observations to radiative transfer models over a wide range of parameter space.https://doi.org/10.3847/1538-4357/adef52Extragalactic astronomyHigh-redshift galaxiesIntergalactic mediumPolarimetry |
| spellingShingle | Eunchong Kim Yujin Yang Sung-Joon Park Ann Zabludoff Paul Smith Myung Gyoon Lee Woong-Seob Jeong Buell Jannuzi Narae Hwang Byeong-Gon Park Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae The Astrophysical Journal Extragalactic astronomy High-redshift galaxies Intergalactic medium Polarimetry |
| title | Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae |
| title_full | Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae |
| title_fullStr | Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae |
| title_full_unstemmed | Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae |
| title_short | Using Polarization to Uncover the Lyα Emission Mechanism in Lyα Nebulae |
| title_sort | using polarization to uncover the lyα emission mechanism in lyα nebulae |
| topic | Extragalactic astronomy High-redshift galaxies Intergalactic medium Polarimetry |
| url | https://doi.org/10.3847/1538-4357/adef52 |
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