Compact to extended Lyman-$α$ emitters in MAGPI: strong blue peak emission at $z\gtrsim3$

• DOI: 10.48550/arxiv.2311.07019
• Publication Date: 2023-01-01
• Authors: Tamal Mukherjee; T. Zafar; Themiya Nanayakkara; Emily Wisnioski; Andrew Battisti; Anshu Gupta; Claudia del P. Lagos; K. E. Harborne; Caroline Foster; J. Trevor Mendel; S. M. Croom; Anilkumar Mailvag...; Jahang Prathap
• Keywords: Astrophysics of Galaxies (astro-ph.GA); FOS: Physical sciences; Astrophysics - Astrophysics of Galaxies

We report the discovery of three double-peaked Lyman-$\alpha$ emitters (LAEs) exhibiting strong blue peak emission at 2.9 $\lesssim z \lesssim$ 4.8, in VLT/MUSE data obtained as part Middle Ages Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey. These systems provide a unique window into scattering photons by neutral hydrogen (HI), suggesting gas inflows along line-of-sight and low HI column density. Two them $z=2.9$ $z=3.6$ are spatially extended halos their core regions clearly stronger emissions than red peak. However, spatial variations ratio separation evident over $25\times 26$ kpc ($z=2.9$) $19\times28$ ($z=3.6$) these halos. Notably, do not fall regime blobs or nebulae. To best our knowledge, such halo dominant has been observed previously. In contrast, LAE $z\sim4.8$ is compact system spanning $9\times9$ region stands highest-redshift emitter ever detected. The bright cores ranges from $\Delta_{\mathrm{peak}}\sim370$ to $660$ km/s. overall trend decreasing increasing radius supposed be controlled density covering fraction. Based on various estimations, contrast LAE, found good candidates for LyC leakers. findings shed light complex interplay between emission, kinematics, ionising radiation properties, offering valuable insights evolution nature high-redshift galaxies.