J/A+A/644/A140 VVVEXMAP-BULGE High resolution reddening map (Surot+, 2020)
Mapping the stellar age of the Milky Way bulge with the VVV.
III. High resolution reddening map.
Surot F., Valenti E., Gonzalez O. A., Zoccali M., Soekmen E., Hidalgo S. L.,
Minniti D.
<Astron. Astrophys. 644, A140 (2020)>
=2020A&A...644A.140S 2020A&A...644A.140S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Reddening
Keywords: Galaxy: structure - Galaxy: bulge
Abstract:
A detailed study of the Galactic bulge stellar population necessarily
requires an accurate representation of the interstellar extinction,
particularly toward the Galactic plane and center, where severe and
differential reddening is expected to vary on sub-arcmin scales.
Although recent infrared surveys have addressed this problem by
providing extinction maps across the whole Galactic bulge area,
dereddened color-magnitude diagrams near the plane and center appear
systematically undercorrected, prompting the need for higher
resolution. These undercorrections affect any stellar study sensitive
to color (e.g., star formation history analyses via color-magnitude
diagram fitting), either making them inaccurate or limiting them to
small and relatively stable extinction windows where this value is low
and better constrained. This study is aimed at providing a
high-resolution (2-arcmin to 10-arcsec) color excess map for the VVV
bulge area in J-Ks color. We used the MW-BULGE-PSFPHOT catalogs,
sampling 300deg2 across the Galactic bulge (|l|<10° and
-10°<b<5°) to isolate a sample of red clump and red giant
branch stars, for which we calculated the average J-Ks color in a fine
spatial grid in (l, b) space. We obtained an E(J-Ks) map spanning the
VVV bulge area of roughly 300deg2, with the equivalent of a
resolution between 1-arcmin for bulge outskirts (l←6°) to below
20-arcsec within the central |l|<1°, and below 10-arcsec for the
innermost area (|l|<1° and |b|<3°). The results are publicly
available at http://basti-iac.oa-teramo.inaf.it/vvvexmap/
Description:
Here we provide the database for E(J-Ks) color excess based on VVV bulge
data VVVEXMAP-BULGE. The database is comprised of 196 bulge fields maps of
1.5x1.2deg2 of VVV, each one based on deep photometric data in JKs from
MS-BULGE-PSFPHOT and defined on a regular grid of 610x500 nodes, covering
the range of (l,b) of each VVV bulge tile. The resolution of the maps ranges
between 6 arcmin to a few arcsecs, depending on stellar density (higher near
Galactic plane and center). For each node we provide their galactic
coordinates, E(J-Ks), estimated error, average resolution (measured as the
average separation of the tracer stars to the center of the node), maximum
resolution (as the maximum separation), as well as tile of origin. The
dispersion of E(J-Ks) for each node can be recovered by multiplying the
E(J-Ks) error by sqrt(20).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ejkmap.dat 52 59780000 VVVEXMAP-BULGE database
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See also:
J/A+A/629/A1 : Mapping the stellar age of the Milky Way (Surot+, 2019)
Byte-by-byte Description of file: ejkmap.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg GLON [] Galactic longitude of the node
12- 21 F10.6 deg GLAT Galactic latitude of the node
23- 27 F5.3 mag E(J-Ks) Reddening
29- 33 F5.3 mag e_E(J-Ks) Error on E(J-Ks)
35- 40 F6.4 arcmin res-avg Average resolution
42- 47 F6.4 arcmin res-max Maximum resolution
49- 52 A4 --- Tile Field ID following VVV designation (bNNN)
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Acknowledgements:
Francisco Surot, frsurot(at)uc.cl
References:
Surot et al., Paper I 2019A&A...623A.168S 2019A&A...623A.168S
Surot et al., Paper II 2019A&A...629A...1S 2019A&A...629A...1S, Cat. J/A+A/629/A1
(End) Francisco Surot [IAC, Spain], Patricia Vannier [CDS] 21-Oct-2020