Disentangling the origin of chemical differences using GHOST

Fuente: arXiv
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Auteurs principaux: Saffe, C., Miquelarena, P., Alacoria, J., Martioli, E., Flores, M., Arancibia, M. Jaque, Angeloni, R., Jofre, E., Galarza, J. Yana, Gonzalez, E., Collado, A.
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Publié: 2024
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author Saffe, C.
Miquelarena, P.
Alacoria, J.
Martioli, E.
Flores, M.
Arancibia, M. Jaque
Angeloni, R.
Jofre, E.
Galarza, J. Yana
Gonzalez, E.
Collado, A.
author_facet Saffe, C.
Miquelarena, P.
Alacoria, J.
Martioli, E.
Flores, M.
Arancibia, M. Jaque
Angeloni, R.
Jofre, E.
Galarza, J. Yana
Gonzalez, E.
Collado, A.
contents Aims. We explore different scenarios to explain the chemical difference found in the remarkable giant-giant binary system HD 138202 + CD-30 12303. For the first time, we suggest how to distinguish these scenarios by taking advantage of the extensive convective envelopes of giant stars. Methods. We carried out a high-precision determination of stellar parameters and abundances by applying a full line-by-line differential analysis on GHOST high-resolution spectra. Results. We found a significant chemical difference between the two stars (0.08 dex), which is largely unexpected considering the insensitivity of giant stars to planetary ingestion and diffusion effects. We tested the possibility of engulfment events by using several different combinations of stellar mass, ingested mass, metallicity of the engulfed object and different convective envelopes. However, the planetary ingestion scenario does not seem to explain the observed differences. For the first time, we distinguished the source of chemical differences using a giant-giant binary system. By ruling out other possible scenarios such as planet formation and evolutionary effects between the two stars, we suggest that primordial inhomogeneities might explain the observed differences. This remarkable result implies that the metallicity differences that were observed in at least some main-sequence binary systems might be related to primordial inhomogeneities rather than engulfment events. We also discuss the important implications of finding primordial inhomogeneities, which affect chemical tagging and other fields such as planet formation. We strongly encourage the use of giant-giant pairs. They are a relevant complement to main-sequence pairs for determining the origin of the observed chemical differences in multiple systems. [abridged]
format Preprint
id arxiv_https___arxiv_org_abs_2402_09278
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Disentangling the origin of chemical differences using GHOST
Saffe, C.
Miquelarena, P.
Alacoria, J.
Martioli, E.
Flores, M.
Arancibia, M. Jaque
Angeloni, R.
Jofre, E.
Galarza, J. Yana
Gonzalez, E.
Collado, A.
Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
Aims. We explore different scenarios to explain the chemical difference found in the remarkable giant-giant binary system HD 138202 + CD-30 12303. For the first time, we suggest how to distinguish these scenarios by taking advantage of the extensive convective envelopes of giant stars. Methods. We carried out a high-precision determination of stellar parameters and abundances by applying a full line-by-line differential analysis on GHOST high-resolution spectra. Results. We found a significant chemical difference between the two stars (0.08 dex), which is largely unexpected considering the insensitivity of giant stars to planetary ingestion and diffusion effects. We tested the possibility of engulfment events by using several different combinations of stellar mass, ingested mass, metallicity of the engulfed object and different convective envelopes. However, the planetary ingestion scenario does not seem to explain the observed differences. For the first time, we distinguished the source of chemical differences using a giant-giant binary system. By ruling out other possible scenarios such as planet formation and evolutionary effects between the two stars, we suggest that primordial inhomogeneities might explain the observed differences. This remarkable result implies that the metallicity differences that were observed in at least some main-sequence binary systems might be related to primordial inhomogeneities rather than engulfment events. We also discuss the important implications of finding primordial inhomogeneities, which affect chemical tagging and other fields such as planet formation. We strongly encourage the use of giant-giant pairs. They are a relevant complement to main-sequence pairs for determining the origin of the observed chemical differences in multiple systems. [abridged]
title Disentangling the origin of chemical differences using GHOST
topic Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
url https://arxiv.org/abs/2402.09278