J/PAZh/43/521 3D map of reddening and interstellar extinction (Gontcharov, 2017)
3D stellar reddening map from 2MASS photometry: An improved version.
Gontcharov G.A.
<Pis'ma Astron. Zh. 43, 521 (2017)>
=2017AstL...43..472G 2017AstL...43..472G
=2017PAZh...43..521G 2017PAZh...43..521G (SIMBAD/NED BibCode)
ADC_Keywords: Extinction ; Interstellar medium ; Milky Way ; Reddening
Keywords: color-magnitude diagram - interstellar medium -
Galactic solar neighborhoods - dark clouds - stellar reddening -
interstellar extinction - Milky Way Galaxy
Abstract:
An improved version of the 3D stellar reddening map in a space with a
radius of 1200 pc around the Sun and within 600 pc of the Galactic
midplane is presented. As in the previous 2010 and 2012 versions of
the map, photometry with an accuracy better than 0.05 mag in the J and
Ks bands for more than 70 million stars from the 2MASS catalogue is
used in the new version. However, the data reduction technique is
considerably more complicated. As before, an analysis of the
distribution of stars near the main-sequence turnoff on the (J-Ks)-Ks
diagram, where they form a distribution maximum, provides a basis for
the method. The shift of this maximum, i.e., the mode (J-Ks), along
(J-Ks) and Ks, given the spatial variations of the mean dereddened
color (J-Ks)0 of these stars, is interpreted as a growth of the
reddening with increasing distance. The main distinction of the new
method is that instead of the fixed mean absolute magnitude,
dereddened color, distance, and reddening for each cell, the
individual values of these quantities are calculated for each star by
iterations when solving the system of equations relating them. This
has allowed one to increase the random accuracy of the map to 0.01mag
and its spatial resolution to 20pc in coordinates and distance and to
1° in longitude and latitude. Comparison with other reddening
estimates for the same spatial cells and Gaia DR1 TGAS stars shows
that the constructed map is one of the best maps for the space under
consideration. Its systematic errors have been estimated to be
σ(E(J-Ks)=0.025mag, or σ(E(B-V))=0.04mag. The main purpose
of the map is to analyze the characteristics of Galactic structures,
clouds, and cloud complexes. For this purpose, the reddening map
within each spatial cell has also been computed by analyzing the
reddening along each line of sight.
Description:
This is a 3D map giving reddening and interstellar extinction for the
net of X, Y, Z or l, b, R Galactic coordinates within R<1200 pc and
|Z|<600 pc as well as for every point by trilinear interpolation. The
quality of this map has been tested by successful positioning of the
TGAS O-F main sequence stars on the HR diagram among the PARSEC and
MIST theoretical isochrones.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
xyzejk.dat 41 630109 E(J-Ks), E(B-V), Rv and Av tabulated as a
function of X, Y, Z coordinates
rlbejk.dat 17 2868450 E(J-Ks) tabulated as a function of R, l, b
coordinates
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/PAZh/38/15 : Total-to-selective extinction ratio within 700 pc
(Gontcharov, 2012)
J/PAZh/36/615 : Three-dimensional reddening map for stars from 2MASS
photometry: The method and the first results (Gontcharov, 2010)
Byte-by-byte Description of file: xyzejk.dat
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Bytes Format Units Label Explanations
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1- 5 I5 pc X [-1200,1200] X rectangular galactic coordinate
6- 11 I6 pc Y [-1200,1200] Y rectangular galactic coordinate
12- 16 I5 pc Z [-600,600] Z rectangular galactic coordinate
17- 23 F7.3 mag E(J-Ks) [-0.003,0.491] E(J-Ks) reddening
24- 30 F7.3 mag E(B-V) [-0.005,0.813] E(B-V) reddening (1)
31- 35 F5.2 --- Rv [1.78,5.46] Rv total-to-selective extinction
ratio (2)
36- 41 F6.2 mag Av [-0.02,2.52] Av interstellar extinction (3)
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Note (1): The E(B-V) are calculated as 1.655*E(J-Ks) following the PARSEC
extinction law
Note (2): The Rv are taken from the paper 2012AstL...38...12G 2012AstL...38...12G and then
interpolated
Note (3): The Av are the product of E(B-V) and Rv.
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Byte-by-byte Description of file: rlbejk.dat
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Bytes Format Units Label Explanations
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1- 4 I4 pc R [0,1200] Heliocentric distance
5- 8 I4 deg GLON [0,359] Galactic longitude
9- 12 I4 deg GLAT [-90,90] Galactic latitude
13- 17 F5.3 mag E(J-Ks) [-0.001,0.489] E(J-Ks) reddening
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Acknowledgements:
George Gontcharov, george.gontcharov(at)tdt.edu.vn
(End) George Gontcharov [Ton Duc Thang Univ.] Patricia Vannier [CDS] 31-Jul-2017