Gespeichert in:
| Hauptverfasser: | , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | https://arxiv.org/abs/2501.07548 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866912719412658176 |
|---|---|
| author | Kim, Keunho Alavi, Anahita Snapp-Kolas, Christopher Siana, Brian Richard, Johan Teplitz, Harry Colbert, James Mehta, Vihang Paulino-Afonso, Ana Vanzella, Eros |
| author_facet | Kim, Keunho Alavi, Anahita Snapp-Kolas, Christopher Siana, Brian Richard, Johan Teplitz, Harry Colbert, James Mehta, Vihang Paulino-Afonso, Ana Vanzella, Eros |
| contents | The mechanisms of Ly$α$ photon escape are key to understanding galaxy evolution and cosmic reionization, yet remain poorly understood. We investigate the UV-continuum sizes of 23 Ly$α$ emitters (LAEs) at Cosmic Noon ($1.7 < z < 3.3$), extending previous size analyses to include fainter galaxies ($M_{\rm UV} \simeq -14$) using gravitational lensing. Our results show that these LAEs are unusually small for their luminosity, with a mean effective radius ($r_{\rm eff}$) of $170 \pm 140$ pc. They follow a distinct size-luminosity relation, with an intercept at $M_{\rm UV} = -21$ approximately three times smaller than typical star-forming galaxies (SFGs) at similar redshifts. This relation, however, is consistent with that of low-redshift Green Pea galaxies, suggesting that LAEs maintain compact sizes across redshifts. We also find that Ly$α$ equivalent width (EW(Ly$α$)) increases with decreasing $r_{\rm eff}$, confirming previous findings. The small sizes of LAEs lead to high star formation surface densities ($Σ$SFR $= 1-600 M_{\odot} \ \rm{yr}^{-1} \ \rm{kpc^{-2}}$), clearly separating them from typical SFGs in the $Σ$SFR vs. $r_{\rm eff}$ space. Given that high $Σ$SFR is linked to strong galactic outflows, our findings imply that compact morphology plays a key role in Ly$α$ escape, likely facilitated by outflows that clear under-dense channels in the ISM. Thus, these results demonstrate that compact size and high $Σ$SFR can help identify Ly$α$-emitters. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_07548 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Compact Size, High $Σ$SFR: Defining Morphological Features of Ly$α$-Emitters Kim, Keunho Alavi, Anahita Snapp-Kolas, Christopher Siana, Brian Richard, Johan Teplitz, Harry Colbert, James Mehta, Vihang Paulino-Afonso, Ana Vanzella, Eros Astrophysics of Galaxies The mechanisms of Ly$α$ photon escape are key to understanding galaxy evolution and cosmic reionization, yet remain poorly understood. We investigate the UV-continuum sizes of 23 Ly$α$ emitters (LAEs) at Cosmic Noon ($1.7 < z < 3.3$), extending previous size analyses to include fainter galaxies ($M_{\rm UV} \simeq -14$) using gravitational lensing. Our results show that these LAEs are unusually small for their luminosity, with a mean effective radius ($r_{\rm eff}$) of $170 \pm 140$ pc. They follow a distinct size-luminosity relation, with an intercept at $M_{\rm UV} = -21$ approximately three times smaller than typical star-forming galaxies (SFGs) at similar redshifts. This relation, however, is consistent with that of low-redshift Green Pea galaxies, suggesting that LAEs maintain compact sizes across redshifts. We also find that Ly$α$ equivalent width (EW(Ly$α$)) increases with decreasing $r_{\rm eff}$, confirming previous findings. The small sizes of LAEs lead to high star formation surface densities ($Σ$SFR $= 1-600 M_{\odot} \ \rm{yr}^{-1} \ \rm{kpc^{-2}}$), clearly separating them from typical SFGs in the $Σ$SFR vs. $r_{\rm eff}$ space. Given that high $Σ$SFR is linked to strong galactic outflows, our findings imply that compact morphology plays a key role in Ly$α$ escape, likely facilitated by outflows that clear under-dense channels in the ISM. Thus, these results demonstrate that compact size and high $Σ$SFR can help identify Ly$α$-emitters. |
| title | Compact Size, High $Σ$SFR: Defining Morphological Features of Ly$α$-Emitters |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2501.07548 |