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Main Authors: Mead, Jennifer, Ness, Melissa, Andersson, Eric, Griffith, Emily J., Horta, Danny
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2403.04833
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author Mead, Jennifer
Ness, Melissa
Andersson, Eric
Griffith, Emily J.
Horta, Danny
author_facet Mead, Jennifer
Ness, Melissa
Andersson, Eric
Griffith, Emily J.
Horta, Danny
contents The first generations of stars left their chemical fingerprints on metal-poor stars in the Milky Way and its surrounding dwarf galaxies. While instantaneous and homogeneous enrichment implies that groups of co-natal stars should have the same element abundances, small amplitudes of abundance scatter are seen at fixed [Fe/H]. Measurements of intrinsic abundance scatter have been made with small, high-resolution spectroscopic datasets where measurement uncertainty is small compared to this scatter. In this work, we present a method to use mid-resolution survey data, which has larger errors, to make this measurement. Using APOGEE DR17, we calculate the intrinsic scatter of Al, O, Mg, Si, Ti, Ni, and Mn relative to Fe for 333 metal-poor stars across 6 classical dwarf galaxies around the Milky Way, and 1604 stars across 19 globular clusters. We first calibrate the reported abundance errors in bins of signal-to-noise and [Fe/H] using a high-fidelity halo dataset. We then apply these calibrated errors to the APOGEE data, and find small amplitudes of average intrinsic abundance scatter in dwarf galaxies ranging from 0.032 - 0.14 dex with a median value of 0.043 dex. For the globular clusters, we find intrinsic scatters ranging from 0.018 - 0.21 dex, with particularly high scatter for Al and O. Our measurements of intrinsic abundance scatter place important upper limits on the intrinsic scatter in these systems, as well as constraints on their underlying star formation history and mixing, that we can look to simulations to interpret.
format Preprint
id arxiv_https___arxiv_org_abs_2403_04833
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Measuring Dwarf Galaxy Intrinsic Abundance Scatter with Mid-resolution Spectroscopic Surveys: Calibrating APOGEE Abundance Errors
Mead, Jennifer
Ness, Melissa
Andersson, Eric
Griffith, Emily J.
Horta, Danny
Astrophysics of Galaxies
The first generations of stars left their chemical fingerprints on metal-poor stars in the Milky Way and its surrounding dwarf galaxies. While instantaneous and homogeneous enrichment implies that groups of co-natal stars should have the same element abundances, small amplitudes of abundance scatter are seen at fixed [Fe/H]. Measurements of intrinsic abundance scatter have been made with small, high-resolution spectroscopic datasets where measurement uncertainty is small compared to this scatter. In this work, we present a method to use mid-resolution survey data, which has larger errors, to make this measurement. Using APOGEE DR17, we calculate the intrinsic scatter of Al, O, Mg, Si, Ti, Ni, and Mn relative to Fe for 333 metal-poor stars across 6 classical dwarf galaxies around the Milky Way, and 1604 stars across 19 globular clusters. We first calibrate the reported abundance errors in bins of signal-to-noise and [Fe/H] using a high-fidelity halo dataset. We then apply these calibrated errors to the APOGEE data, and find small amplitudes of average intrinsic abundance scatter in dwarf galaxies ranging from 0.032 - 0.14 dex with a median value of 0.043 dex. For the globular clusters, we find intrinsic scatters ranging from 0.018 - 0.21 dex, with particularly high scatter for Al and O. Our measurements of intrinsic abundance scatter place important upper limits on the intrinsic scatter in these systems, as well as constraints on their underlying star formation history and mixing, that we can look to simulations to interpret.
title Measuring Dwarf Galaxy Intrinsic Abundance Scatter with Mid-resolution Spectroscopic Surveys: Calibrating APOGEE Abundance Errors
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2403.04833