Mapping the Milky Way bulge at high resolution: The 3D dust extinction, CO, and X factor maps

M. Schultheis, B. Q. Chen, B. W. Jiang, O. A. Gonzalez, R. Enokiya, Y. Fukui, K. Torii, M. Rejkuba, D. Minniti

Resultado de la investigación: Article

53 Citas (Scopus)

Resumen

Context. Three dimensional interstellar extinction maps provide a powerful tool for stellar population analysis. However, until now, these 3D maps were rather limited by sensitivity and spatial resolution. Aims. We use data from the VISTA Variables in the Via Lactea survey together with the Besançon stellar population synthesis model of the Galaxy to determine interstellar extinction as a function of distance in the Galactic bulge covering -10° < l < 10° and -10° < b < 5°. Methods. We adopted a recently developed method to calculate the colour excess. First we constructed the H - Ks vs. Ks and J - Ks vs. Ks colour-magnitude diagrams based on the VVV catalogues that matched 2MASS. Then, based on the temperature-colour relation for M giants and the distance-colour relations, we derived the extinction as a function of distance. The observed colours were shifted to match the intrinsic colours in the Besançon model as a function of distance iteratively. This created an extinction map with three dimensions: two spatial and one distance dimension along each line of sight towards the bulge. Results. We present a 3D extinction map that covers the whole VVV area with a resolution of 6′ × 6′ for J - Ks and H - Ks using distance bins of 0.5 kpc. The high resolution and depth of the photometry allows us to derive extinction maps for a range of distances up to 10 kpc and up to 30 mag of extinction in AV (3.0 mag in AKs). Integrated maps show the same dust features and consistent values as other 2D maps. We discuss the spatial distribution of dust features in the line of sight, which suggests that there is much material in front of the Galactic bar, specifically between 5-7 kpc. We compare our dust extinction map with the high-resolution 12CO maps (NANTEN2) towards the Galactic bulge, where we find a good correlation between 12CO and AV. We determine the X factor by combining the CO map and our dust extinction map. Our derived average value X = 2.5 ± 0.47 × 1020cm-2 K-1km-1s is consistent with the canonical value of the Milky Way. The X-factor decreases with increasing extinction.

Idioma originalEnglish
Número de artículoA120
PublicaciónAstronomy and Astrophysics
Volumen566
DOI
EstadoPublished - 2014

Huella dactilar

extinction
dust
high resolution
color
interstellar extinction
galactic bulge
line of sight
color-magnitude diagram
catalogs
photometry
spatial distribution
spatial resolution
coverings
diagram
galaxies
sensitivity
synthesis

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Schultheis, M. ; Chen, B. Q. ; Jiang, B. W. ; Gonzalez, O. A. ; Enokiya, R. ; Fukui, Y. ; Torii, K. ; Rejkuba, M. ; Minniti, D. / Mapping the Milky Way bulge at high resolution : The 3D dust extinction, CO, and X factor maps. En: Astronomy and Astrophysics. 2014 ; Vol. 566.
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title = "Mapping the Milky Way bulge at high resolution: The 3D dust extinction, CO, and X factor maps",
abstract = "Context. Three dimensional interstellar extinction maps provide a powerful tool for stellar population analysis. However, until now, these 3D maps were rather limited by sensitivity and spatial resolution. Aims. We use data from the VISTA Variables in the Via Lactea survey together with the Besan{\cc}on stellar population synthesis model of the Galaxy to determine interstellar extinction as a function of distance in the Galactic bulge covering -10° < l < 10° and -10° < b < 5°. Methods. We adopted a recently developed method to calculate the colour excess. First we constructed the H - Ks vs. Ks and J - Ks vs. Ks colour-magnitude diagrams based on the VVV catalogues that matched 2MASS. Then, based on the temperature-colour relation for M giants and the distance-colour relations, we derived the extinction as a function of distance. The observed colours were shifted to match the intrinsic colours in the Besan{\cc}on model as a function of distance iteratively. This created an extinction map with three dimensions: two spatial and one distance dimension along each line of sight towards the bulge. Results. We present a 3D extinction map that covers the whole VVV area with a resolution of 6′ × 6′ for J - Ks and H - Ks using distance bins of 0.5 kpc. The high resolution and depth of the photometry allows us to derive extinction maps for a range of distances up to 10 kpc and up to 30 mag of extinction in AV (3.0 mag in AKs). Integrated maps show the same dust features and consistent values as other 2D maps. We discuss the spatial distribution of dust features in the line of sight, which suggests that there is much material in front of the Galactic bar, specifically between 5-7 kpc. We compare our dust extinction map with the high-resolution 12CO maps (NANTEN2) towards the Galactic bulge, where we find a good correlation between 12CO and AV. We determine the X factor by combining the CO map and our dust extinction map. Our derived average value X = 2.5 ± 0.47 × 1020cm-2 K-1km-1s is consistent with the canonical value of the Milky Way. The X-factor decreases with increasing extinction.",
keywords = "Dust, Extinction, Galaxy: Bulge, Galaxy: Stellar content",
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Schultheis, M, Chen, BQ, Jiang, BW, Gonzalez, OA, Enokiya, R, Fukui, Y, Torii, K, Rejkuba, M & Minniti, D 2014, 'Mapping the Milky Way bulge at high resolution: The 3D dust extinction, CO, and X factor maps', Astronomy and Astrophysics, vol. 566, A120. https://doi.org/10.1051/0004-6361/201322788

Mapping the Milky Way bulge at high resolution : The 3D dust extinction, CO, and X factor maps. / Schultheis, M.; Chen, B. Q.; Jiang, B. W.; Gonzalez, O. A.; Enokiya, R.; Fukui, Y.; Torii, K.; Rejkuba, M.; Minniti, D.

En: Astronomy and Astrophysics, Vol. 566, A120, 2014.

Resultado de la investigación: Article

TY - JOUR

T1 - Mapping the Milky Way bulge at high resolution

T2 - The 3D dust extinction, CO, and X factor maps

AU - Schultheis, M.

AU - Chen, B. Q.

AU - Jiang, B. W.

AU - Gonzalez, O. A.

AU - Enokiya, R.

AU - Fukui, Y.

AU - Torii, K.

AU - Rejkuba, M.

AU - Minniti, D.

PY - 2014

Y1 - 2014

N2 - Context. Three dimensional interstellar extinction maps provide a powerful tool for stellar population analysis. However, until now, these 3D maps were rather limited by sensitivity and spatial resolution. Aims. We use data from the VISTA Variables in the Via Lactea survey together with the Besançon stellar population synthesis model of the Galaxy to determine interstellar extinction as a function of distance in the Galactic bulge covering -10° < l < 10° and -10° < b < 5°. Methods. We adopted a recently developed method to calculate the colour excess. First we constructed the H - Ks vs. Ks and J - Ks vs. Ks colour-magnitude diagrams based on the VVV catalogues that matched 2MASS. Then, based on the temperature-colour relation for M giants and the distance-colour relations, we derived the extinction as a function of distance. The observed colours were shifted to match the intrinsic colours in the Besançon model as a function of distance iteratively. This created an extinction map with three dimensions: two spatial and one distance dimension along each line of sight towards the bulge. Results. We present a 3D extinction map that covers the whole VVV area with a resolution of 6′ × 6′ for J - Ks and H - Ks using distance bins of 0.5 kpc. The high resolution and depth of the photometry allows us to derive extinction maps for a range of distances up to 10 kpc and up to 30 mag of extinction in AV (3.0 mag in AKs). Integrated maps show the same dust features and consistent values as other 2D maps. We discuss the spatial distribution of dust features in the line of sight, which suggests that there is much material in front of the Galactic bar, specifically between 5-7 kpc. We compare our dust extinction map with the high-resolution 12CO maps (NANTEN2) towards the Galactic bulge, where we find a good correlation between 12CO and AV. We determine the X factor by combining the CO map and our dust extinction map. Our derived average value X = 2.5 ± 0.47 × 1020cm-2 K-1km-1s is consistent with the canonical value of the Milky Way. The X-factor decreases with increasing extinction.

AB - Context. Three dimensional interstellar extinction maps provide a powerful tool for stellar population analysis. However, until now, these 3D maps were rather limited by sensitivity and spatial resolution. Aims. We use data from the VISTA Variables in the Via Lactea survey together with the Besançon stellar population synthesis model of the Galaxy to determine interstellar extinction as a function of distance in the Galactic bulge covering -10° < l < 10° and -10° < b < 5°. Methods. We adopted a recently developed method to calculate the colour excess. First we constructed the H - Ks vs. Ks and J - Ks vs. Ks colour-magnitude diagrams based on the VVV catalogues that matched 2MASS. Then, based on the temperature-colour relation for M giants and the distance-colour relations, we derived the extinction as a function of distance. The observed colours were shifted to match the intrinsic colours in the Besançon model as a function of distance iteratively. This created an extinction map with three dimensions: two spatial and one distance dimension along each line of sight towards the bulge. Results. We present a 3D extinction map that covers the whole VVV area with a resolution of 6′ × 6′ for J - Ks and H - Ks using distance bins of 0.5 kpc. The high resolution and depth of the photometry allows us to derive extinction maps for a range of distances up to 10 kpc and up to 30 mag of extinction in AV (3.0 mag in AKs). Integrated maps show the same dust features and consistent values as other 2D maps. We discuss the spatial distribution of dust features in the line of sight, which suggests that there is much material in front of the Galactic bar, specifically between 5-7 kpc. We compare our dust extinction map with the high-resolution 12CO maps (NANTEN2) towards the Galactic bulge, where we find a good correlation between 12CO and AV. We determine the X factor by combining the CO map and our dust extinction map. Our derived average value X = 2.5 ± 0.47 × 1020cm-2 K-1km-1s is consistent with the canonical value of the Milky Way. The X-factor decreases with increasing extinction.

KW - Dust

KW - Extinction

KW - Galaxy: Bulge

KW - Galaxy: Stellar content

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U2 - 10.1051/0004-6361/201322788

DO - 10.1051/0004-6361/201322788

M3 - Article

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VL - 566

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

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