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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)> =2017PAZh...43..521G (SIMBAD/NED BibCode) =2017AstL...43..472G
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:
FileName Lrecl Records Explanations
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
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
Bytes Format Units Label Explanations
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)
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 and then interpolated Note (3): The Av are the product of E(B-V) and Rv.
Byte-by-byte Description of file: rlbejk.dat
Bytes Format Units Label Explanations
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
Acknowledgements: George Gontcharov, george.gontcharov(at)
(End) George Gontcharov [Ton Duc Thang Univ.] Patricia Vannier [CDS] 31-Jul-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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