On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5
We use medium- and high-resolution spectroscopy of close pairs of quasars to analyze the circumgalactic medium (CGM) surrounding 32 damped Ly α absorption systems (DLAs). The primary quasar sightline in each pair probes an intervening DLA in the redshift range 1.6 < z _abs < 3.5, such that the...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acd34a |
| _version_ | 1797698993597186048 |
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| author | Stephanie M. Urbano Stawinski Kate H. R. Rubin J. Xavier Prochaska Joseph F. Hennawi Nicolas Tejos Michele Fumagalli Marc Rafelski Evan N. Kirby Elisabeta Lusso Zachary Hafen |
| author_facet | Stephanie M. Urbano Stawinski Kate H. R. Rubin J. Xavier Prochaska Joseph F. Hennawi Nicolas Tejos Michele Fumagalli Marc Rafelski Evan N. Kirby Elisabeta Lusso Zachary Hafen |
| author_sort | Stephanie M. Urbano Stawinski |
| collection | DOAJ |
| description | We use medium- and high-resolution spectroscopy of close pairs of quasars to analyze the circumgalactic medium (CGM) surrounding 32 damped Ly α absorption systems (DLAs). The primary quasar sightline in each pair probes an intervening DLA in the redshift range 1.6 < z _abs < 3.5, such that the secondary sightline probes absorption from Ly α and a large suite of metal-line transitions (including O i , C ii , C iv , Si ii , and Si iv ) in the DLA host galaxy’s CGM at transverse distances 24 kpc ≤ R _⊥ ≤ 284 kpc. Analysis of Ly α in the CGM sightlines shows an anticorrelation between R _⊥ and H i column density ( N _HI ) with 99.8% confidence, similar to that observed around luminous galaxies. The incidences of C ii and Si ii with N > 10 ^13 cm ^−2 within 100 kpc of DLAs are larger by 2 σ than those measured in the CGM of Lyman break galaxies (C _f ( N _C _II ) > 0.89 and ${{\rm{C}}}_{f}({N}_{\mathrm{Si}{\rm\small{II}}})={0.75}_{-0.17}^{+0.12}$ ). Metallicity constraints derived from ionic ratios for nine CGM systems with negligible ionization corrections and N _HI > 10 ^18.5 cm ^−2 show a significant degree of scatter (with metallicities/limits across the range $-2.06\lesssim \mathrm{log}Z/{Z}_{\odot }\lesssim -0.75$ ), suggesting inhomogeneity in the metal distribution in these environments. Velocity widths of C iv λ 1548 and low-ionization metal species in the DLA versus CGM sightlines are strongly (>2 σ ) correlated, suggesting that they trace the potential well of the host halo over R _⊥ ≲ 300 kpc scales. At the same time, velocity centroids for C iv λ 1548 differ in DLA versus CGM sightlines by >100 km s ^−1 for ∼50% of velocity components, but few components have velocities that would exceed the escape velocity assuming dark matter host halos of ≥10 ^12 M _⊙ . |
| first_indexed | 2024-03-12T04:02:07Z |
| format | Article |
| id | doaj.art-db415530394b4c7e94c103805b9aa3d5 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:02:07Z |
| publishDate | 2023-01-01 |
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| series | The Astrophysical Journal |
| spelling | doaj.art-db415530394b4c7e94c103805b9aa3d52023-09-03T11:33:00ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01951213510.3847/1538-4357/acd34aOn the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5Stephanie M. Urbano Stawinski0https://orcid.org/0000-0001-8169-7249Kate H. R. Rubin1https://orcid.org/0000-0001-6248-1864J. Xavier Prochaska2https://orcid.org/0000-0002-7738-6875Joseph F. Hennawi3https://orcid.org/0000-0002-7054-4332Nicolas Tejos4https://orcid.org/0000-0002-1883-4252Michele Fumagalli5https://orcid.org/0000-0001-6676-3842Marc Rafelski6https://orcid.org/0000-0002-9946-4731Evan N. Kirby7https://orcid.org/0000-0001-6196-5162Elisabeta Lusso8https://orcid.org/0000-0003-0083-1157Zachary Hafen9https://orcid.org/0000-0001-7326-1736Department of Physics and Astronomy, University of California , Irvine, CA 92697, USA ; ststawinski@gmail.comDepartment of Astronomy, San Diego State University , San Diego, CA 92182 USA; Center for Astrophysics and Space Sciences, University of California , San Diego, La Jolla, CA 92093, USADepartment of Astronomy & Astrophysics, University of California , 1156 High Street, Santa Cruz, CA 95064, USA; University of California Observatories , Lick Observatory, 1156 High Street, Santa Cruz, CA 95064, USA; Kavli Institute for the Physics and Mathematics of the Universe (WIP) , 5-1-5 Kashiwanoha, Kashiwa, 277-8583, JapanDepartment of Physics, Broida Hall, University of California , Santa Barbara, CA 93106, USA; Max-Planck-Institut fuer Astronomie , Koenigstuhl 17, D-69117 Heidelberg, GermanyInstituto de Física, Pontificia Universidad Católica de Valparaíso , Casilla 4059, Valparaíso, ChileDipartimento 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. Tiepolo 11, Trieste, ItalySpace Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA; Department of Physics & Astronomy, Johns Hopkins University , Baltimore, MD 21218, USACalifornia Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA; Department of Physics, University of Notre Dame , Notre Dame, IN 46556, USADipartimento di Fisica e Astronomia, Università di Firenze , via G. Sansone 1, i-50019 Sesto Fiorentino, Firenze, Italy; INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze, ItalyDepartment of Physics and Astronomy, University of California , Irvine, CA 92697, USA ; ststawinski@gmail.comWe use medium- and high-resolution spectroscopy of close pairs of quasars to analyze the circumgalactic medium (CGM) surrounding 32 damped Ly α absorption systems (DLAs). The primary quasar sightline in each pair probes an intervening DLA in the redshift range 1.6 < z _abs < 3.5, such that the secondary sightline probes absorption from Ly α and a large suite of metal-line transitions (including O i , C ii , C iv , Si ii , and Si iv ) in the DLA host galaxy’s CGM at transverse distances 24 kpc ≤ R _⊥ ≤ 284 kpc. Analysis of Ly α in the CGM sightlines shows an anticorrelation between R _⊥ and H i column density ( N _HI ) with 99.8% confidence, similar to that observed around luminous galaxies. The incidences of C ii and Si ii with N > 10 ^13 cm ^−2 within 100 kpc of DLAs are larger by 2 σ than those measured in the CGM of Lyman break galaxies (C _f ( N _C _II ) > 0.89 and ${{\rm{C}}}_{f}({N}_{\mathrm{Si}{\rm\small{II}}})={0.75}_{-0.17}^{+0.12}$ ). Metallicity constraints derived from ionic ratios for nine CGM systems with negligible ionization corrections and N _HI > 10 ^18.5 cm ^−2 show a significant degree of scatter (with metallicities/limits across the range $-2.06\lesssim \mathrm{log}Z/{Z}_{\odot }\lesssim -0.75$ ), suggesting inhomogeneity in the metal distribution in these environments. Velocity widths of C iv λ 1548 and low-ionization metal species in the DLA versus CGM sightlines are strongly (>2 σ ) correlated, suggesting that they trace the potential well of the host halo over R _⊥ ≲ 300 kpc scales. At the same time, velocity centroids for C iv λ 1548 differ in DLA versus CGM sightlines by >100 km s ^−1 for ∼50% of velocity components, but few components have velocities that would exceed the escape velocity assuming dark matter host halos of ≥10 ^12 M _⊙ .https://doi.org/10.3847/1538-4357/acd34aCircumgalactic mediumDamped Lyman-alpha systemsQuasar absorption-line spectroscopy |
| spellingShingle | Stephanie M. Urbano Stawinski Kate H. R. Rubin J. Xavier Prochaska Joseph F. Hennawi Nicolas Tejos Michele Fumagalli Marc Rafelski Evan N. Kirby Elisabeta Lusso Zachary Hafen On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 The Astrophysical Journal Circumgalactic medium Damped Lyman-alpha systems Quasar absorption-line spectroscopy |
| title | On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 |
| title_full | On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 |
| title_fullStr | On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 |
| title_full_unstemmed | On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 |
| title_short | On the Metallicities and Kinematics of the Circumgalactic Media of Damped Lyα Systems at z ∼ 2.5 |
| title_sort | on the metallicities and kinematics of the circumgalactic media of damped lyα systems at z ∼ 2 5 |
| topic | Circumgalactic medium Damped Lyman-alpha systems Quasar absorption-line spectroscopy |
| url | https://doi.org/10.3847/1538-4357/acd34a |
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