The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc
We present new high-resolution ( R ∼ 114,000), near-ultraviolet spectra in the direction of 36 nearby (<100 pc) stars to uncover the structure and composition of the local interstellar medium (LISM). The spectra were obtained using the Space Telescope Imaging Spectrograph on board the Hubble Spa...
| Published in: | The Astrophysical Journal |
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| Main Authors: | , , , , |
| Format: | Article |
| Language: | English |
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IOP Publishing
2025-01-01
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| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adb960 |
| _version_ | 1849722899907215360 |
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| author | Azmain H. Nisak Seth Redfield Jeffrey L. Linsky Brian E. Wood Allison Youngblood |
| author_facet | Azmain H. Nisak Seth Redfield Jeffrey L. Linsky Brian E. Wood Allison Youngblood |
| author_sort | Azmain H. Nisak |
| collection | DOAJ |
| container_title | The Astrophysical Journal |
| description | We present new high-resolution ( R ∼ 114,000), near-ultraviolet spectra in the direction of 36 nearby (<100 pc) stars to uncover the structure and composition of the local interstellar medium (LISM). The spectra were obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We model the LISM absorption due to Mg ii , Fe ii , and Mn ii in order to measure new velocities, Doppler broadening parameters, and column densities for interstellar clouds; refine the extent of known clouds; and identify new clouds. Based on our analyses of these 36 new sight lines, we find one to four discrete LISM features for each individual sight line, with the number of components remaining relatively flat until increasing at ≈60 pc. By comparing our final measurements with a dynamical model of the LISM by S. Redfield & J. L. Linsky, we determine that 77% of the predictions made by the kinematic model are confirmed by observed components in the new lines of sight and identify 10 LISM features among eight sight lines that do not match the model. In addition to testing and refining three-dimensional kinematic models of the LISM, the substantially increased number of integrated Mg ii emission fluxes presented here will be valuable for predicting the far-ultraviolet and extreme-ultraviolet emission for these stars. We also find that six stars in our sample show possible circumstellar disk absorption, including 47 UMa, for which a disk has not yet been confirmed. |
| format | Article |
| id | doaj-art-0a366d30eef54f4d9880eebb013d7c88 |
| institution | Directory of Open Access Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| spelling | doaj-art-0a366d30eef54f4d9880eebb013d7c882025-08-20T01:50:30ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-019831510.3847/1538-4357/adb960The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pcAzmain H. Nisak0Seth Redfield1https://orcid.org/0000-0003-3786-3486Jeffrey L. Linsky2https://orcid.org/0000-0003-4446-3181Brian E. Wood3https://orcid.org/0000-0002-4998-0893Allison Youngblood4https://orcid.org/0000-0002-1176-3391Department of Astronomy and Van Vleck Observatory, Wesleyan University , Middletown, CT 06459, USA ; anisak@wesleyan.edu, sredfield@wesleyan.eduDepartment of Astronomy and Van Vleck Observatory, Wesleyan University , Middletown, CT 06459, USA ; anisak@wesleyan.edu, sredfield@wesleyan.eduJILA, University of Colorado and NIST , Boulder, CO 80309-0440, USA ; jlinsky@jila.colorado.eduNaval Research Laboratory , Space Science Division, Washington, DC 20375, USA ; brian.wood@nrl.navy.milExoplanets and Stellar Astrophysics Lab, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA ; allison.a.youngblood@nasa.govWe present new high-resolution ( R ∼ 114,000), near-ultraviolet spectra in the direction of 36 nearby (<100 pc) stars to uncover the structure and composition of the local interstellar medium (LISM). The spectra were obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We model the LISM absorption due to Mg ii , Fe ii , and Mn ii in order to measure new velocities, Doppler broadening parameters, and column densities for interstellar clouds; refine the extent of known clouds; and identify new clouds. Based on our analyses of these 36 new sight lines, we find one to four discrete LISM features for each individual sight line, with the number of components remaining relatively flat until increasing at ≈60 pc. By comparing our final measurements with a dynamical model of the LISM by S. Redfield & J. L. Linsky, we determine that 77% of the predictions made by the kinematic model are confirmed by observed components in the new lines of sight and identify 10 LISM features among eight sight lines that do not match the model. In addition to testing and refining three-dimensional kinematic models of the LISM, the substantially increased number of integrated Mg ii emission fluxes presented here will be valuable for predicting the far-ultraviolet and extreme-ultraviolet emission for these stars. We also find that six stars in our sample show possible circumstellar disk absorption, including 47 UMa, for which a disk has not yet been confirmed.https://doi.org/10.3847/1538-4357/adb960Interstellar absorptionInterstellar cloudsInterstellar medium |
| spellingShingle | Azmain H. Nisak Seth Redfield Jeffrey L. Linsky Brian E. Wood Allison Youngblood The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc Interstellar absorption Interstellar clouds Interstellar medium |
| title | The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc |
| title_full | The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc |
| title_fullStr | The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc |
| title_full_unstemmed | The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc |
| title_short | The Structure of the Local Interstellar Medium. VII. Additional New Mg ii, Fe ii, and Mn ii Observations toward Stars within 100 pc |
| title_sort | structure of the local interstellar medium vii additional new mg ii fe ii and mn ii observations toward stars within 100 pc |
| topic | Interstellar absorption Interstellar clouds Interstellar medium |
| url | https://doi.org/10.3847/1538-4357/adb960 |
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