KBSS-InCLOSE. I. Design and First Results from the Inner Circumgalactic Medium of QSO Line-of-sight Emitting Galaxies at z ∼ 2–3 * * Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Nuñez, Evan Haze; Steidel, Charles C.; Kirby, Evan N.; Rudie, Gwen C.; Prusinski, Nikolaus Z.; Chen, Yuguang; Zhuang, Zhuyun; Strom, Allison L.; Erb, Dawn K.; Pettini, Max; Welsh, Louise; Rupke, David S. N.; Cooke, Ryan J.

Abstract

We present the design and first results of the inner circumgalactic medium (CGM) of QSO line-of-sight emitting galaxies at z ∼ 2–3, Keck Baryonic Structure Survey (KBSS)-InCLOSE. The survey will connect galaxy properties (e.g., stellar mass M *, interstellar medium, hereafter ISM, metallicity) with the physical conditions of the inner CGM (e.g., kinematics, metallicity) to directly observe the galaxy-scale baryon cycle. We obtain deep Keck/KCWI optical IFU pointings of KBSS QSOs to discover new star-forming galaxies at small projected distances b ≲ 12″ (98 kpc, z¯=2.3 ), then obtain follow-up Keck/MOSFIRE near-IR spectra to confirm their redshifts. We leverage KBSS images and Keck/High Resolution Echelle Spectrometer QSO spectra to model stellar populations and inner CGM absorption. In this paper, we analyze two QSO fields and discover more than 15 new galaxies with KCWI, then use MOSFIRE for two galaxies Q2343-G1 (z = 2.43; G1) and Q2233-N1 (z = 3.15; N1), which are both associated with damped Lyα absorbers. We find that G1 has typical M *, UV/optical emission properties. N1 has lower M * with very strong nebular emission. We jointly analyze neutral phase CGM and ionized ISM in N/O (for the first time at this z), dust extinction, and high-ionization CGM finding that G1's CGM is metal poor and less evolved than its ISM, while N1's CGM and ISM abundances are comparable; their CGM shows ∼1 dex less dust extinction than the ISM; and G1's CGM has direct evidence of hot, metal-rich galactic outflow ejecta. These findings support that metals and dust are driven into the CGM from outflows, but may also be, e.g., stripped ISM gas or satellite enrichment. The full KBSS-InCLOSE sample will explore these scenarios.

Citation

Nuñez, E. H., Steidel, C. C., Kirby, E. N., Rudie, G. C., Prusinski, N. Z., Chen, Y., Zhuang, Z., Strom, A. L., Erb, D. K., Pettini, M., Welsh, L., Rupke, D. S. N., & Cooke, R. J. (2024). KBSS-InCLOSE. I. Design and First Results from the Inner Circumgalactic Medium of QSO Line-of-sight Emitting Galaxies at z ∼ 2–3 * * Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The Astrophysical Journal, 976(1), Article 41. https://doi.org/10.3847/1538-4357/ad70b6

• Journal Article Type: Article
• Acceptance Date: Aug 16, 2024
• Online Publication Date: Nov 15, 2024
• Publication Date: Nov 1, 2024
• Deposit Date: Nov 20, 2024
• Publicly Available Date: Nov 20, 2024
• Journal: The Astrophysical Journal
• Electronic ISSN: 1538-4357
• Peer Reviewed: Peer Reviewed
• Volume: 976
• Issue: 1
• Article Number: 41
• DOI: https://doi.org/10.3847/1538-4357/ad70b6
• Keywords: Abundance ratios, Extragalactic astronomy, Quasar absorption line spectroscopy, Circumgalactic medium, Interstellar medium, Intergalactic medium, Damped Lyman-alpha systems, Galaxy chemical evolution
• Public URL: https://durham-repository.worktribe.com/output/3098869