GHOST commissioning science results - III. Characterizing an iron-poor damped Lyman α system

The Gemini High-resolution Optical SpecTrograph (GHOST) is a new Echelle spectrograph available on the Gemini-South telescope as of Semester 2024A. We present the first high-resolution spectrum of the quasar J1449 -1227 (redshift z em = 3.27) using data taken during the commissioning of GHOST. The observed quasar hosts an intervening iron-poor { [Fe/H] = -2.5 } damped Lyman αsystem (DLA) at redshift z = 2.904. Taking advantage of the high spectral resolving power of GHOST ( R ≈ 55 000), we are able to accurately model the metal absorption lines of the metal-poor DLA and find a supersolar [Si/Fe], suggesting that the DLA gas is in an early stage of chemical enrichment. Using simple ionization models, we find that the large range in the C IV /Si IV column density ratio of individual components within the DLA's high-ionization absorption profile can be reproduced by several metal-poor Lyman limit systems surrounding the low-ionization gas of the DLA. It is possible that this metal-poor DLA resides within a complex system of metal-poor galaxies or filaments with inflowing gas. The high spectral resolution, wav elength co v erage, and sensitivity of GHOST make it an ideal spectrograph for characterizing the chemistry and kinematics of quasar absorption lines.