Resolving circumgalactic gas flows around a
Springer Link (Chiba Institute of Technology)
Abstract
The formation and evolution of galaxies is regulated by the exchange of gas with the surrounding large-scale structures on circum- and intergalactic scales, yet little is known about the complex processes shaping the cycle of baryons in and out of galaxies. In this work, we present a multiline study of the gas surrounding a z ≈ 3.66 quasar known to host one of the brightest Lyα nebulae at high redshift, MUSE Quasar Nebula 04 (MQN04). By combining a high-resolution MUSE detection of nonresonant He II emission with a precise measurement of the redshift of the quasar host via the ALMA CO(4–3) line, we study the kinematics of the cool ionized gas down to #x2248; 1 kpc from the quasar. The MUSE observations reveal complex clumpy structures as well as diffuse emission extended over ≈100 kpc and blueshifted by ≈0 − 800 km s−1 relative to the quasar systemic redshift, suggesting that the circumgalactic medium is highly asymmetric. The analysis of the He II/Lyα line ratio, and the presence of a low-column density (≈ 1014.6 cm−2) H I absorber along the quasar sightline suggests that MQN04 resides in a highly ionized medium. This is also supported by the gas kinematics, which, except in the most central region, shows consistent velocity shifts across the different tracers, indicative of relatively weak radiative transfer effects. Based on its morphology and kinematics, we conclude that the extended He II emission may arise from merger-driven tidal stripping or inflows of gas illuminated by the quasar radiation. On comoving megaparsec scales, we discover a large concentration (δ ≈ 41) of star-forming galaxies lying within |ΔvQSO| ≲ 1000 km s−1 from the quasar. MQN04 is therefore one of the most overdense environments discovered at this epoch.
Authors 13
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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Trieste Astronomical Observatory · University of Milano-Bicocca · National Institute for Astrophysics
Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
INAF-Osservatorio Astronomico di Trieste , Via G.B. Tiepolo , 11 , I-34143 Trieste , Italy
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Affiliation as printed
Kapteyn Astronomical Institute , University of Groningen , Landleven 12 , NL-9747 AD Groningen , the Netherlands
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Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics
Affiliation as printed
INAF-Osservatorio di Astrofisica e Scienza dello Spazio , Via Gobetti 93/3 , I-40129 Bologna , Italy
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Inter-University Centre for Astronomy and Astrophysics
Affiliation as printed
IUCAA , Postbag 4 , Ganeshkind , Pune 411007 , India
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Inter-University Centre for Astronomy and Astrophysics
Affiliation as printed
IUCAA , Postbag 4 , Ganeshkind , Pune 411007 , India
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Leiden University · Leiden Observatory
Affiliation as printed
Leiden Observatory , Leiden University , PO Box 9513 , 2300 RA Leiden , the Netherlands
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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Affiliation as printed
Dipartimento di Fisica "G. Occhialini" , Università degli Studi di Milano-Bicocca , Piazza della Scienza 3 , I-20126 Milano , Italy
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