The GALAH Survey: Classification and Diagnostics with t-SNE Reduction of Spectral Information
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Traven, Gregor; Matijevič, Gal; Zwitter, T; Zerjal, M.; Kos, J.; Asplund, Martin; Bland-Hawthorn, J.; Casey , A R; De Silva, Gayandhi; Freeman, Kenneth; lin, jane; Martell, Sarah; Schlesinger, Katharine; Sharma, Sanjib; Simpson, Jeffrey D.; Da Costa, Gary; Duong, Ly; Nataf, David
Description
Galah is an ongoing high-resolution spectroscopic survey with the goal of disentangling the formation history of the Milky Way using the fossil remnants of disrupted star formation sites that are now dispersed around the Galaxy. It is targeting a randomly selected magnitude-limited (V ≤ 14) sample of stars, with the goal of observing one million objects. To date, 300,000 spectra have been obtained. Not all of them are correctly processed by parameter estimation pipelines, and we need to know...[Show more]
dc.contributor.author | Traven, Gregor | |
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dc.contributor.author | Matijevič, Gal | |
dc.contributor.author | Zwitter, T | |
dc.contributor.author | Zerjal, M. | |
dc.contributor.author | Kos, J. | |
dc.contributor.author | Asplund, Martin | |
dc.contributor.author | Bland-Hawthorn, J. | |
dc.contributor.author | Casey , A R | |
dc.contributor.author | De Silva, Gayandhi | |
dc.contributor.author | Freeman, Kenneth | |
dc.contributor.author | lin, jane | |
dc.contributor.author | Martell, Sarah | |
dc.contributor.author | Schlesinger, Katharine | |
dc.contributor.author | Sharma, Sanjib | |
dc.contributor.author | Simpson, Jeffrey D. | |
dc.contributor.author | Da Costa, Gary | |
dc.contributor.author | Duong, Ly | |
dc.contributor.author | Nataf, David | |
dc.date.accessioned | 2020-12-20T20:58:04Z | |
dc.date.available | 2020-12-20T20:58:04Z | |
dc.identifier.issn | 0067-0049 | |
dc.identifier.uri | http://hdl.handle.net/1885/218476 | |
dc.description.abstract | Galah is an ongoing high-resolution spectroscopic survey with the goal of disentangling the formation history of the Milky Way using the fossil remnants of disrupted star formation sites that are now dispersed around the Galaxy. It is targeting a randomly selected magnitude-limited (V ≤ 14) sample of stars, with the goal of observing one million objects. To date, 300,000 spectra have been obtained. Not all of them are correctly processed by parameter estimation pipelines, and we need to know about them. We present a semi-automated classification scheme that identifies different types of peculiar spectral morphologies in an effort to discover and flag potentially problematic spectra and thus help to preserve the integrity of the survey results. To this end, we employ the recently developed dimensionality reduction technique t-SNE (t-distributed stochastic neighbor embedding), which enables us to represent the complex spectral morphology in a two-dimensional projection map while still preserving the properties of the local neighborhoods of spectra. We find that the majority (178,483) of the 209,533 Galah spectra considered in this study represents normal single stars, whereas 31,050 peculiar and problematic spectra with very diverse spectral features pertaining to 28,579 stars are distributed into 10 classification categories: hot stars, cool metal-poor giants, molecular absorption bands, binary stars, Hμ/Hβ emission, Hμ/Hβ emission superimposed on absorption, Hμ/Hβ P-Cygni, Hμ/Hβ inverted P-Cygni, lithium absorption, and problematic. Classified spectra with supplementary information are presented in the catalog, indicating candidates for follow-up observations and population studies of the short-lived phases of stellar evolution | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en_AU | |
dc.publisher | Institute of Physics Publishing | |
dc.source | Astrophysical Journal Supplement Series | |
dc.title | The GALAH Survey: Classification and Diagnostics with t-SNE Reduction of Spectral Information | |
dc.type | Journal article | |
local.description.notes | Imported from ARIES | |
local.identifier.citationvolume | 228 | |
dc.date.issued | 2017 | |
local.identifier.absfor | 020104 - Galactic Astronomy | |
local.identifier.ariespublication | a383154xPUB5382 | |
local.type.status | Metadata only | |
local.contributor.affiliation | Traven, Gregor, University of Ljubljana | |
local.contributor.affiliation | Matijevič, Gal, University of Ljubljana | |
local.contributor.affiliation | Zwitter, T, University of Ljubljana | |
local.contributor.affiliation | Zerjal, M., University of Ljubljana | |
local.contributor.affiliation | Kos, J. , University of Ljubljana | |
local.contributor.affiliation | Asplund, Martin, College of Science, ANU | |
local.contributor.affiliation | Bland-Hawthorn, J., The University of Sydney | |
local.contributor.affiliation | Casey , A R, University of Cambridge | |
local.contributor.affiliation | De Silva, Gayandhi, Australian Astronomical Observatory | |
local.contributor.affiliation | Freeman, Kenneth, College of Science, ANU | |
local.contributor.affiliation | lin, jane, College of Science, ANU | |
local.contributor.affiliation | Martell, Sarah, University of New South Wales | |
local.contributor.affiliation | Schlesinger, Katharine, College of Science, ANU | |
local.contributor.affiliation | Sharma, Sanjib, The University of Sydney | |
local.contributor.affiliation | Simpson, Jeffrey D., Australian Astronomical Observatory | |
local.contributor.affiliation | Da Costa, Gary, College of Science, ANU | |
local.contributor.affiliation | Duong, Ly, College of Science, ANU | |
local.contributor.affiliation | Nataf, David, College of Science, ANU | |
local.bibliographicCitation.issue | 2 | |
local.identifier.doi | 10.3847/1538-4365/228/2/24 | |
dc.date.updated | 2020-11-23T11:16:46Z | |
local.identifier.scopusID | 2-s2.0-85014831098 | |
local.identifier.thomsonID | 000397312500002 | |
Collections | ANU Research Publications |
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