Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE
H ii region electron temperatures are a critical ingredient in metallicity determinations, and recent observations have revealed systematic variations in the temperatures measured using different ions. We present electron temperatures (T e ) measured using the optical auroral lines ([N ii]λ5756, [O...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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American Astronomical Society
2024
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| _version_ | 1826313572713496576 |
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| author | Rickards Vaught, RJ Sandstrom, KM Belfiore, F Kreckel, K Méndez-Delgado, JE Emsellem, E Groves, B Blanc, GA Dale, DA Egorov, OV Glover, SCO Grasha, K Klessen, RS Neumann, J Williams, TG |
| author_facet | Rickards Vaught, RJ Sandstrom, KM Belfiore, F Kreckel, K Méndez-Delgado, JE Emsellem, E Groves, B Blanc, GA Dale, DA Egorov, OV Glover, SCO Grasha, K Klessen, RS Neumann, J Williams, TG |
| author_sort | Rickards Vaught, RJ |
| collection | OXFORD |
| description | H ii region electron temperatures are a critical ingredient in metallicity determinations, and recent observations have revealed systematic variations in the temperatures measured using different ions. We present electron temperatures (T e ) measured using the optical auroral lines ([N ii]λ5756, [O ii]λ λ7320, 7330, [S ii]λ λ4069, 4076, [O iii]λ4363, and [S iii]λ6312) for a sample of H ii regions in seven nearby galaxies. We use observations from the Physics at High Angular resolution in Nearby Galaxies survey (PHANGS) obtained with integral field spectrographs on Keck (Keck Cosmic Web Imager) and the Very Large Telescope (Multi-Unit Spectroscopic Explorer). We compare the different T e measurements with H ii region and ISM environmental properties such as electron density, ionization parameter, molecular gas velocity dispersion, and stellar association/cluster mass and age obtained from PHANGS. We find that the temperatures from [O ii] and [S ii] are likely overestimated due to the presence of electron density inhomogeneities in H ii regions. We measure high [O iii] temperatures in a subset of regions with high molecular gas velocity dispersion and low ionization parameter, which may be explained by the presence of low-velocity shocks. In agreement with previous studies, the T e–T e between [N ii] and [S iii] temperatures have the lowest observed scatter and follow predictions from photoionization modeling, which suggests that these tracers reflect H ii region temperatures across the various ionization zones better than [O ii], [S ii], and [O iii]. |
| first_indexed | 2024-09-25T04:15:27Z |
| format | Journal article |
| id | oxford-uuid:65818a19-9cc8-43d1-8394-e9006dbbc4e3 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-09-25T04:15:27Z |
| publishDate | 2024 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | oxford-uuid:65818a19-9cc8-43d1-8394-e9006dbbc4e32024-07-20T14:43:58ZInvestigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSEJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:65818a19-9cc8-43d1-8394-e9006dbbc4e3EnglishJisc Publications RouterAmerican Astronomical Society2024Rickards Vaught, RJSandstrom, KMBelfiore, FKreckel, KMéndez-Delgado, JEEmsellem, EGroves, BBlanc, GADale, DAEgorov, OVGlover, SCOGrasha, KKlessen, RSNeumann, JWilliams, TGH ii region electron temperatures are a critical ingredient in metallicity determinations, and recent observations have revealed systematic variations in the temperatures measured using different ions. We present electron temperatures (T e ) measured using the optical auroral lines ([N ii]λ5756, [O ii]λ λ7320, 7330, [S ii]λ λ4069, 4076, [O iii]λ4363, and [S iii]λ6312) for a sample of H ii regions in seven nearby galaxies. We use observations from the Physics at High Angular resolution in Nearby Galaxies survey (PHANGS) obtained with integral field spectrographs on Keck (Keck Cosmic Web Imager) and the Very Large Telescope (Multi-Unit Spectroscopic Explorer). We compare the different T e measurements with H ii region and ISM environmental properties such as electron density, ionization parameter, molecular gas velocity dispersion, and stellar association/cluster mass and age obtained from PHANGS. We find that the temperatures from [O ii] and [S ii] are likely overestimated due to the presence of electron density inhomogeneities in H ii regions. We measure high [O iii] temperatures in a subset of regions with high molecular gas velocity dispersion and low ionization parameter, which may be explained by the presence of low-velocity shocks. In agreement with previous studies, the T e–T e between [N ii] and [S iii] temperatures have the lowest observed scatter and follow predictions from photoionization modeling, which suggests that these tracers reflect H ii region temperatures across the various ionization zones better than [O ii], [S ii], and [O iii]. |
| spellingShingle | Rickards Vaught, RJ Sandstrom, KM Belfiore, F Kreckel, K Méndez-Delgado, JE Emsellem, E Groves, B Blanc, GA Dale, DA Egorov, OV Glover, SCO Grasha, K Klessen, RS Neumann, J Williams, TG Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title | Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title_full | Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title_fullStr | Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title_full_unstemmed | Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title_short | Investigating the Drivers of Electron Temperature Variations in H ii Regions with Keck-KCWI and VLT-MUSE |
| title_sort | investigating the drivers of electron temperature variations in h ii regions with keck kcwi and vlt muse |
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