Stellar Models are Reliable at Low Metallicity: An Asteroseismic Age for the Ancient Very Metal-Poor Star KIC 8144907
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866913444747280384 |
|---|---|
| author | Huber, Daniel Slumstrup, Ditte Hon, Marc Li, Yaguang Borsen-Koch, Victor Aguirre Bedding, Timothy R. Joyce, Meridith Ong, J. M. Joel Serenelli, Aldo Stello, Dennis Berger, Travis Grunblatt, Samuel K. Greklek-McKeon, Michael Hirano, Teruyuki Kirby, Evan N. Pinsonneault, Marc H. Puls, Arthur Alencastro Zinn, Joel |
| author_facet | Huber, Daniel Slumstrup, Ditte Hon, Marc Li, Yaguang Borsen-Koch, Victor Aguirre Bedding, Timothy R. Joyce, Meridith Ong, J. M. Joel Serenelli, Aldo Stello, Dennis Berger, Travis Grunblatt, Samuel K. Greklek-McKeon, Michael Hirano, Teruyuki Kirby, Evan N. Pinsonneault, Marc H. Puls, Arthur Alencastro Zinn, Joel |
| contents | Very metal-poor stars ([Fe/H]<-2) are important laboratories for testing stellar models and reconstructing the formation history of our galaxy. Asteroseismology is a powerful tool to probe stellar interiors and measure ages, but few asteroseismic detections are known in very metal-poor stars and none have allowed detailed modeling of oscillation frequencies. We report the discovery of a low-luminosity Kepler red giant (KIC 8144907) with high S/N oscillations, [Fe/H]=-2.66+/-0.08 and [alpha/Fe]=0.38+/-0.06, making it by far the most metal-poor star to date for which detailed asteroseismic modeling is possible. By combining the oscillation spectrum from Kepler with high-resolution spectroscopy we measure an asteroseismic mass and age of 0.79+/-0.02(ran)+/-0.01(sys) Msun and 12.0+/-0.6(ran)+/-0.4(sys) Gyr, with remarkable agreement across different codes and input physics, demonstrating that stellar models and asteroseismology are reliable for very metal-poor stars when individual frequencies are used. The results also provide a direct age anchor for the early formation of the Milky Way, implying that substantial star formation did not commence until redshift z~3 (if the star formed in-situ) or that the Milky Way has undergone merger events for at least ~12 Gyr (if the star was accreted by a dwarf satellite merger such as Gaia Enceladus). |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2407_17566 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Stellar Models are Reliable at Low Metallicity: An Asteroseismic Age for the Ancient Very Metal-Poor Star KIC 8144907 Huber, Daniel Slumstrup, Ditte Hon, Marc Li, Yaguang Borsen-Koch, Victor Aguirre Bedding, Timothy R. Joyce, Meridith Ong, J. M. Joel Serenelli, Aldo Stello, Dennis Berger, Travis Grunblatt, Samuel K. Greklek-McKeon, Michael Hirano, Teruyuki Kirby, Evan N. Pinsonneault, Marc H. Puls, Arthur Alencastro Zinn, Joel Solar and Stellar Astrophysics Astrophysics of Galaxies Very metal-poor stars ([Fe/H]<-2) are important laboratories for testing stellar models and reconstructing the formation history of our galaxy. Asteroseismology is a powerful tool to probe stellar interiors and measure ages, but few asteroseismic detections are known in very metal-poor stars and none have allowed detailed modeling of oscillation frequencies. We report the discovery of a low-luminosity Kepler red giant (KIC 8144907) with high S/N oscillations, [Fe/H]=-2.66+/-0.08 and [alpha/Fe]=0.38+/-0.06, making it by far the most metal-poor star to date for which detailed asteroseismic modeling is possible. By combining the oscillation spectrum from Kepler with high-resolution spectroscopy we measure an asteroseismic mass and age of 0.79+/-0.02(ran)+/-0.01(sys) Msun and 12.0+/-0.6(ran)+/-0.4(sys) Gyr, with remarkable agreement across different codes and input physics, demonstrating that stellar models and asteroseismology are reliable for very metal-poor stars when individual frequencies are used. The results also provide a direct age anchor for the early formation of the Milky Way, implying that substantial star formation did not commence until redshift z~3 (if the star formed in-situ) or that the Milky Way has undergone merger events for at least ~12 Gyr (if the star was accreted by a dwarf satellite merger such as Gaia Enceladus). |
| title | Stellar Models are Reliable at Low Metallicity: An Asteroseismic Age for the Ancient Very Metal-Poor Star KIC 8144907 |
| topic | Solar and Stellar Astrophysics Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2407.17566 |