Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data

Bibliographic Details
Main Author: Pieres, Adriano
Publication Date: 2020
Other Authors: Santiago, Basilio Xavier, DES Collaboration
Format: Article
Language: eng
Source: Repositório Institucional da UFRGS
Download full: http://hdl.handle.net/10183/217893
Summary: We present a technique to fit the stellar components of the Galaxy by comparing Hess Diagrams (HDs) generated from TRILEGAL models to real data. We apply this technique, which we call MWFITTING, to photometric data from the first 3 yr of the Dark Energy Survey (DES). After removing regions containing known resolved stellar systems such as globular clusters, dwarf galaxies, nearby galaxies, the Large Magellanic Cloud, and the Sagittarius Stream, our main sample spans a total area of ∼2300 deg2. We further explore a smaller subset (∼1300 deg2) that excludes all regions with known stellar streams and stellar overdensities. Validation tests on synthetic data possessing similar properties to the DES data show that the method is able to recover input parameters with a precision better than 3 per cent. We fit the DES data with an exponential thick disc model and an oblate double power-law halo model. We find that the best-fitting thick disc model has radial and vertical scale heights of 2.67 ± 0.09 kpc and 925 ± 40 pc, respectively. The stellar halo is fit with a broken power-law density profile with an oblateness of 0.75 ± 0.01, an inner index of 1.82 ± 0.08, an outer index of 4.14 ± 0.05, and a break at 18.52 ± 0.27 kpc from the Galactic centre. Several previously discovered stellar overdensities are recovered in the residual stellar density map, showing the reliability of MWFITTING in determining the Galactic components. Simulations made with the best-fitting parameters are a promising way to predict Milky Way star counts for surveys such as the LSST and Euclid.
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spelling Pieres, AdrianoSantiago, Basilio XavierDES Collaboration2021-02-11T04:10:33Z20200035-8711http://hdl.handle.net/10183/217893001120674We present a technique to fit the stellar components of the Galaxy by comparing Hess Diagrams (HDs) generated from TRILEGAL models to real data. We apply this technique, which we call MWFITTING, to photometric data from the first 3 yr of the Dark Energy Survey (DES). After removing regions containing known resolved stellar systems such as globular clusters, dwarf galaxies, nearby galaxies, the Large Magellanic Cloud, and the Sagittarius Stream, our main sample spans a total area of ∼2300 deg2. We further explore a smaller subset (∼1300 deg2) that excludes all regions with known stellar streams and stellar overdensities. Validation tests on synthetic data possessing similar properties to the DES data show that the method is able to recover input parameters with a precision better than 3 per cent. We fit the DES data with an exponential thick disc model and an oblate double power-law halo model. We find that the best-fitting thick disc model has radial and vertical scale heights of 2.67 ± 0.09 kpc and 925 ± 40 pc, respectively. The stellar halo is fit with a broken power-law density profile with an oblateness of 0.75 ± 0.01, an inner index of 1.82 ± 0.08, an outer index of 4.14 ± 0.05, and a break at 18.52 ± 0.27 kpc from the Galactic centre. Several previously discovered stellar overdensities are recovered in the residual stellar density map, showing the reliability of MWFITTING in determining the Galactic components. Simulations made with the best-fitting parameters are a promising way to predict Milky Way star counts for surveys such as the LSST and Euclid.application/pdfengMonthly notices of the royal astronomical society. Oxford. Vol. 497, no. 2 (Sept. 2020), p. 1547-1562GaláxiasVia lácteaHalosGalaxy: structureGalaxy: stellar contentGalaxy: haloModelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 dataEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001120674.pdf.txt001120674.pdf.txtExtracted Texttext/plain88190http://www.lume.ufrgs.br/bitstream/10183/217893/2/001120674.pdf.txte843a465bff74d4d92e70627b0ad36adMD52ORIGINAL001120674.pdfTexto completo (inglês)application/pdf3969997http://www.lume.ufrgs.br/bitstream/10183/217893/1/001120674.pdf4d2556125a04d96874f8bb437cbf65a0MD5110183/2178932023-07-02 03:41:11.021547oai:www.lume.ufrgs.br:10183/217893Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2023-07-02T06:41:11Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false
dc.title.pt_BR.fl_str_mv Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
title Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
spellingShingle Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
Pieres, Adriano
Galáxias
Via láctea
Halos
Galaxy: structure
Galaxy: stellar content
Galaxy: halo
title_short Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
title_full Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
title_fullStr Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
title_full_unstemmed Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
title_sort Modelling the Milky Way : I. Method and first results fitting the thick disc and halo with DES-Y3 data
author Pieres, Adriano
author_facet Pieres, Adriano
Santiago, Basilio Xavier
DES Collaboration
author_role author
author2 Santiago, Basilio Xavier
DES Collaboration
author2_role author
author
dc.contributor.author.fl_str_mv Pieres, Adriano
Santiago, Basilio Xavier
DES Collaboration
dc.subject.por.fl_str_mv Galáxias
Via láctea
Halos
topic Galáxias
Via láctea
Halos
Galaxy: structure
Galaxy: stellar content
Galaxy: halo
dc.subject.eng.fl_str_mv Galaxy: structure
Galaxy: stellar content
Galaxy: halo
description We present a technique to fit the stellar components of the Galaxy by comparing Hess Diagrams (HDs) generated from TRILEGAL models to real data. We apply this technique, which we call MWFITTING, to photometric data from the first 3 yr of the Dark Energy Survey (DES). After removing regions containing known resolved stellar systems such as globular clusters, dwarf galaxies, nearby galaxies, the Large Magellanic Cloud, and the Sagittarius Stream, our main sample spans a total area of ∼2300 deg2. We further explore a smaller subset (∼1300 deg2) that excludes all regions with known stellar streams and stellar overdensities. Validation tests on synthetic data possessing similar properties to the DES data show that the method is able to recover input parameters with a precision better than 3 per cent. We fit the DES data with an exponential thick disc model and an oblate double power-law halo model. We find that the best-fitting thick disc model has radial and vertical scale heights of 2.67 ± 0.09 kpc and 925 ± 40 pc, respectively. The stellar halo is fit with a broken power-law density profile with an oblateness of 0.75 ± 0.01, an inner index of 1.82 ± 0.08, an outer index of 4.14 ± 0.05, and a break at 18.52 ± 0.27 kpc from the Galactic centre. Several previously discovered stellar overdensities are recovered in the residual stellar density map, showing the reliability of MWFITTING in determining the Galactic components. Simulations made with the best-fitting parameters are a promising way to predict Milky Way star counts for surveys such as the LSST and Euclid.
publishDate 2020
dc.date.issued.fl_str_mv 2020
dc.date.accessioned.fl_str_mv 2021-02-11T04:10:33Z
dc.type.driver.fl_str_mv Estrangeiro
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dc.identifier.uri.fl_str_mv http://hdl.handle.net/10183/217893
dc.identifier.issn.pt_BR.fl_str_mv 0035-8711
dc.identifier.nrb.pt_BR.fl_str_mv 001120674
identifier_str_mv 0035-8711
001120674
url http://hdl.handle.net/10183/217893
dc.language.iso.fl_str_mv eng
language eng
dc.relation.ispartof.pt_BR.fl_str_mv Monthly notices of the royal astronomical society. Oxford. Vol. 497, no. 2 (Sept. 2020), p. 1547-1562
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