NUK - logo
E-viri
Celotno besedilo
Odprti dostop
  • Zou, Hu; Sui, Jipeng; Saintonge, Amélie; Scholte, Dirk; Moustakas, John; Siudek, Malgorzata; Dey, Arjun; Juneau, Stephanie; Guo, Weijian; Canning, Rebecca; Aguilar, J; Ahlen, S; Brooks, D; Claybaugh, T; Dawson, K; de la Macorra, A; Doel, P; ero-Romero, J E; S Gontcho A Gontcho; Honscheid, K; Landriau, M; L Le Guillou; Manera, M; Meisner, A; Miquel, R; Nie, Jundan; Poppett, C; Rezaie, M; Rossi, G; Sanchez, E; Schubnell, M; Seo, H; Tarle, G; Zhou, Zhimin; Zou, Siwei

    arXiv.org, 12/2023
    Paper

    Extremely metal-poor galaxies (XMPGs) at relatively low redshift are excellent laboratories for studying galaxy formation and evolution in the early universe. Much effort has been spent on identifying them from large-scale spectroscopic surveys or spectroscopic follow-up observations. Previous work has identified a few hundred XMPGs. In this work, we obtain a large sample of 223 XMPGs at \(z<1\) from the early data of the Dark Energy Spectroscopic Instrument (DESI). The oxygen abundance is determined using the direct \(T_{\rm e}\) method based on the detection of the O III\(\lambda\)4363 line. The sample includes 95 confirmed XMPGs based on the oxygen abundance uncertainty; remaining 128 galaxies are regarded as XMPG candidates. These XMPGs are only 0.01% of the total DESI observed galaxies. Their coordinates and other proprieties are provided in the paper. The most XMPG has an oxygen abundance of \(\sim 1/34 Z_{\odot}\), stellar mass of about \(1.5\times10^7 M_{\odot}\) and star formation rate of 0.22 \(M_{\odot}\) yr\(^{-1}\). The two most XMPGs present distinct morphologies suggesting different formation mechanisms. The local environmental investigation shows that XMPGs preferentially reside in relatively low-density regions. Many of them fall below the stellar mass-metallicity relations (MZRs) of normal star-forming galaxies. From a comparison of the MZR with theoretical simulations, it appears that XMPGs are good analogs to high-redshift star-forming galaxies. The nature of these XMPG populations will be further investigated in detail with larger and more complete samples from the on-going DESI survey.