A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): JWST Discovers an Overdensity around a Metal Absorption-selected Galaxy at z ～ 5.5

作者：Wu, Yunjing^*; Wang, Feige; Cai, Zheng; Fan, Xiaohui; Finlator, Kristian; Yang, Jinyi; Hennawi, Joseph F.; Sun, Fengwu; Champagne, Jaclyn B.; Lin, Xiaojing; Li, Zihao; Chen, Zuyi; Banados, Eduardo; Becker, George D.; Bosman, Sarah E. I.; Bruzual, Gustavo; Charlot, Stephane; Chen, Hsiao-Wen; Chevallard, Jacopo; Eilers, Anna-Christina; Farina, Emanuele Paolo; Jin, Xiangyu; Jun, Hyunsung D.; Kakiichi, Koki; Li, Mingyu; Liu, Weizhe; Pudoka, Maria A.; Tee, Wei Leong; Xie, Zhang-Liang

来源：Astrophysical Journal Letters, 2023, 956(2): L40.

DOI：10.3847/2041-8213/acfee3

• STAR-FORMATION HISTORIES
• LARGE-SCALE ENVIRONMENT
• MG II ABSORPTION
• C IV ABSORBERS
• LESS-THAN 7
• INTERGALACTIC MEDIUM
• COSMOLOGICAL SIMULATIONS
• CIRCUMGALACTIC MEDIUM
• CIV ABSORPTION
• GALACTIC WINDS

The launch of JWST opens a new window for studying the connection between metal-line absorbers and galaxies at the end of the Epoch of Reionization. Previous studies have detected absorber-galaxy pairs in limited quantities through ground-based observations. To enhance our understanding of the relationship between absorbers and their host galaxies at z > 5, we utilized the NIRCam wide-field slitless spectroscopy to search for absorber-associated galaxies by detecting their rest-frame optical emission lines (e.g., [O III] + H beta). We report the discovery of a Mg ii-associated galaxy at z = 5.428 using data from the JWST ASPIRE program. The Mg ii absorber is detected on the spectrum of quasar J0305-3150 with a rest-frame equivalent width of 0.74 angstrom. The associated galaxy has an [O III] luminosity of 10(42.5) erg s(-1) with an impact parameter of 24.9 pkpc. The joint Hubble Space Telescope-JWST spectral energy distribution (SED) implies a stellar mass and star formation rate of M-* approximate to 10(8.8) M-circle dot, star-formation rate approximate to 10 M-circle dot yr(-1). Its [O III] equivalent width and stellar mass are typical of [O III] emitters at this redshift. Furthermore, connecting the outflow starting time to the SED-derived stellar age, the outflow velocity of this galaxy is similar to 300 km s(-1), consistent with theoretical expectations. We identified six additional [O III] emitters with impact parameters of up to similar to 300 pkpc at similar redshifts ( divide dv divide < 1000 km s(-1)). The observed number is consistent with that in cosmological simulations. This pilot study suggests that systematically investigating the absorber-galaxy connection within the ASPIRE program will provide insights into the metal-enrichment history in the early Universe.

• 单位
  清华大学