J/A+A/625/A135 Galactic interstellar dust Gaia-2MASS 3D maps (Lallement+, 2019)
Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc.
Lallement R., Babusiaux C., Vergely J.L., Katz D., Arenou F., Valette B.,
Hottier C., Capitanio L.
<Astron. Astrophys. 625, A135 (2019)>
=2019A&A...625A.135L 2019A&A...625A.135L (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Extinction
Keywords: dust: extinction - local insterstellar matter - ISM: structure
Abstract:
Gaia stellar measurements are currently revolutionizing our knowledge
of the evolutionary history of the Milky Way. 3D maps of the
interstellar dust provide complementary information and are a tool for
a wide range of uses. We built 3D maps of the dust in the Local arm
and surrounding regions. To do so, Gaia DR2 photometric data were
combined with 2MASS measurements to derive extinction toward stars
that possess accurate photometry and relative uncertainties on DR2
parallaxes smaller than 20%. We applied a new hierarchical inversion
algorithm to the individual extinctions that is adapted to large
datasets and to an inhomogeneous target distribution. Each step
associates regularized Bayesian inversions in all radial directions
and a subsequent inversion in 3D of all their results. Each inverted
distribution serves as a prior for the subsequent step, and the
spatial resolution is progressively increased. We present the
resulting 3D distribution of the dust in a 6x6x0.8kpc3 volume
around the Sun. Its main features are found to be elongated along
different directions that vary from below to above the mid-plane. The
outer part of Carina-Sagittarius, mainly located above the mid-plane,
the Local arm/Cygnus Rift around and above the mid-plane, and the
fragmented Perseus arm are oriented close to the direction of circular
motion. The spur of more than 2kpc length (nicknamed the split) that
extends between the Local Arm and Carina-Sagittarius, the compact near
side of Carina-Sagittarius, and the Cygnus Rift below the Plane are
oriented along l∼40 to 55°. Dust density images in vertical planes
reveal a wavy pattern in some regions and show that the solar
neighborhood within 500 pc remains atypical by its extent above and
below the Plane. We show several comparisons with the locations of
molecular clouds, HII regions, O stars, and masers. The link between
the dust concentration and these tracers is markedly different from
one region to the other
Description:
We have used the Gaia and 2MASS photometric data to estimate the
extinction toward 27 million carefully selected target stars with a
Gaia DR2 parallax uncertainty below 20%. Approximately 16 million
distance-extinction pairs for the closest objects were inverted to
produce 3D maps of the dust density within 400pc from the Plane and
in a 6kpc by 6kpc region along the Plane. To do so, a new
hierarchical inversion algorithm was developed that has the advantage
of adapting the map resolution to the target space density. Following
this procedure, the minimum size of the inverted structures varies
from 25pc (a resolution achieved within 1kpc) to 500pc (in a few
regions that are distant by more than 3kpc from the Sun).
X, Y, Y are Sun-centered cartesian Galactic coordinates. X and Y are
in the midplane, X is directed to the Galactic Center, Y is in the
sense of rotation, Z points to the north Galactic pole.
D(A0)/D(d) is the differential opacity of the interstellar dust at each
point in MAG per PARSEC.
A0 is the extinction at wavelength 5500Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 57 2 List of files
map3DGAIAdr2feb2019.h5 512 1580280 3D map in hdf5 format
STILISM_cube.fits 2880 1290150 3D map in fits format
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Byte-by-byte Description of file: list.dat
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1- 10 I10 byte Size Size of file
12- 35 A24 --- FileName Name of the file
37- 57 A21 --- Title Title of the file
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Acknowledgements:
Rosine Lallement, rosine.lallement(at)obspm.fr
(End) Patricia Vannier [CDS] 24-May-2019