A Census of Double-Peaked Lyman-alpha Emitters in MAGPI: Classification, Global Characteristics, and Spatially Resolved Properties
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866918508455002112 |
|---|---|
| author | Mukherjee, Tamal Zafar, Tayyaba Nanayakkara, Themiya Gurung-Lopez, Siddhartha Gupta, Anshu Croom, Scott M. Battisti, Andrew Glazebrook, Karl Papaderos, Polychronis Riggs, Melissa Wisnioski, Emily Foster, Caroline Harborne, Katherine E. Lagos, Claudia D. P. Mendel, Trevor Prathap, Jahang Barsanti, Stefania Sweet, Sarah M. Valenzuela, Lucas M. Mailvaganam, Anilkumar |
| author_facet | Mukherjee, Tamal Zafar, Tayyaba Nanayakkara, Themiya Gurung-Lopez, Siddhartha Gupta, Anshu Croom, Scott M. Battisti, Andrew Glazebrook, Karl Papaderos, Polychronis Riggs, Melissa Wisnioski, Emily Foster, Caroline Harborne, Katherine E. Lagos, Claudia D. P. Mendel, Trevor Prathap, Jahang Barsanti, Stefania Sweet, Sarah M. Valenzuela, Lucas M. Mailvaganam, Anilkumar |
| contents | Double-peaked Ly$α$ profiles provide critical insights into gas kinematics and the distribution of neutral hydrogen (HI) from the interstellar to the intergalactic medium (ISM to IGM), and serve as valuable diagnostics of ionising Lyman continuum (LyC) photon escape. We present a study of the global and spatially resolved properties of double-peaked Ly$α$ emitters (LAEs) based on VLT/MUSE data from the MAGPI survey. From a parent sample of 417 LAEs at z = 2.9 - 6.6 in the first 35 fields, we identify 108 double-peaked LAEs using an automated peak classification technique. We measure a double-peak fraction of $\sim37\%$ at $z < 4$, decreasing to $\sim14\%$ at $z > 4$, likely due to enhanced IGM attenuation. Approximately $17\%$ of the double-peaked LAEs are blue-dominated, possibly tracing gas inflows, though backscattering remains a viable alternative for sources without systemic redshift. The blue-to-total flux ratio exhibits a luminosity dependence: fainter lines generally show higher blue flux. We find a narrowing of the red peak at $z > 4$, despite the presence of the blue peak, indicating intrinsic galaxy evolution rather than IGM attenuation. Several LAEs exhibit residual flux in the absorption trough, with normalised trough flux anticorrelating with peak separation, reflecting variations in HI column density. We further investigate spatially resolved properties of ten red-dominated LAEs with extended Ly$α$ halos. Despite azimuthal variations, both the blue-to-total flux ratio and normalised trough flux density increase with radius, while peak separation decreases. The red peak asymmetry shows only minor radial changes. These trends are consistent with variations in shell outflow velocity and HI column density across the halos. Based on peak separation, red peak asymmetry, and residual trough flux, we identify five LAEs as strong LyC-leaker candidates. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2510_18398 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | A Census of Double-Peaked Lyman-alpha Emitters in MAGPI: Classification, Global Characteristics, and Spatially Resolved Properties Mukherjee, Tamal Zafar, Tayyaba Nanayakkara, Themiya Gurung-Lopez, Siddhartha Gupta, Anshu Croom, Scott M. Battisti, Andrew Glazebrook, Karl Papaderos, Polychronis Riggs, Melissa Wisnioski, Emily Foster, Caroline Harborne, Katherine E. Lagos, Claudia D. P. Mendel, Trevor Prathap, Jahang Barsanti, Stefania Sweet, Sarah M. Valenzuela, Lucas M. Mailvaganam, Anilkumar Astrophysics of Galaxies Double-peaked Ly$α$ profiles provide critical insights into gas kinematics and the distribution of neutral hydrogen (HI) from the interstellar to the intergalactic medium (ISM to IGM), and serve as valuable diagnostics of ionising Lyman continuum (LyC) photon escape. We present a study of the global and spatially resolved properties of double-peaked Ly$α$ emitters (LAEs) based on VLT/MUSE data from the MAGPI survey. From a parent sample of 417 LAEs at z = 2.9 - 6.6 in the first 35 fields, we identify 108 double-peaked LAEs using an automated peak classification technique. We measure a double-peak fraction of $\sim37\%$ at $z < 4$, decreasing to $\sim14\%$ at $z > 4$, likely due to enhanced IGM attenuation. Approximately $17\%$ of the double-peaked LAEs are blue-dominated, possibly tracing gas inflows, though backscattering remains a viable alternative for sources without systemic redshift. The blue-to-total flux ratio exhibits a luminosity dependence: fainter lines generally show higher blue flux. We find a narrowing of the red peak at $z > 4$, despite the presence of the blue peak, indicating intrinsic galaxy evolution rather than IGM attenuation. Several LAEs exhibit residual flux in the absorption trough, with normalised trough flux anticorrelating with peak separation, reflecting variations in HI column density. We further investigate spatially resolved properties of ten red-dominated LAEs with extended Ly$α$ halos. Despite azimuthal variations, both the blue-to-total flux ratio and normalised trough flux density increase with radius, while peak separation decreases. The red peak asymmetry shows only minor radial changes. These trends are consistent with variations in shell outflow velocity and HI column density across the halos. Based on peak separation, red peak asymmetry, and residual trough flux, we identify five LAEs as strong LyC-leaker candidates. |
| title | A Census of Double-Peaked Lyman-alpha Emitters in MAGPI: Classification, Global Characteristics, and Spatially Resolved Properties |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2510.18398 |