J/MNRAS/500/2590 Gaia DR2 giants in the Galactic dust I (Gontcharov+, 2021)
Gaia DR2 giants in the Galactic dust. I.
Reddening across the whole dust layer and some properties of the giant clump.
Gontcharov G.A., Mosenkov A.V.
<Mon. Not. R. Astron. Soc., 500, 2590-2606 (2021)>
=2021MNRAS.500.2590G 2021MNRAS.500.2590G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Stars, giant ; Stars, nearby ; Milky Way ;
Parallaxes, trigonometric ; Stars, distances ; Optical
Keywords: stars: late-type - dust, extinction - ISM: structure -
local interstellar matter - solar neighbourhood
Abstract:
We consider a complete sample of 101810 giants with Gaia Data Realease
2 (DR2) parallaxes ϖ within the red clump domain of the
Hertzsprung-Russell diagram in the space cylinder with a radius of
700pc around the Sun and a height of |Z|=1800pc. We use the Gaia DR2
GBP, GRP, and Wide-field Infrared Survey Explorer W3 photometry.
We describe the spatial variations of the modes of the observables
GBP-GRP, GRP-W3, GBP+5+5log10ϖ,
GRP+5+5log10ϖ, and W3+5+5log10ϖ by extinction and
reddening in combination with linear vertical gradients of the
intrinsic colours and absolute magnitudes of the red giant clump. The
derived clump median absolute magnitude in W3 agrees with its recent
literature estimates. The clump median intrinsic colours and absolute
magnitudes in GBP and GRP are derived for the first time at a
precision level of 0.01mag. We confirm the reliability of the derived
clump absolute magnitudes, intrinsic colours, and their vertical
gradients by comparing them with the theoretical predictions from the
PAdova and TRieste Stellar Evolution Code, MESA Isochrones and Stellar
Tracks, and Bag of Stellar Tracks and Isochrones. This leads us to the
median age and [Fe/H] of the clump within |Z|<1.7kpc from the Galactic
mid-plane as (2.3±0.5)+(3.2±1.6)|Z|Gyr and
(-0.08±0.08)-(0.16±0.07)|Z|dex, respectively, where Z is expressed
in kpc. These results agree with recent empirical and theoretical
estimates. Moreover, all the models give similar age-metallicity
relations by use of our results in the optical range. The derived
extinctions and reddenings across the whole dust half-layer below or
above the Sun converge to the reddening E(B-V)=0.06mag by use of the
most reliable extinction laws.
Description:
Gaia DR2 provides first accurate parallaxes and optical photometry for
a sample of giants in the clump domain of the HR diagram, which is
complete for a space across the whole Galactic dust layer near the
Sun. In this paper, we have used the observables GBP-GRP,
GRP-W3, MGBP+AGBP=GBP+5+5log10ϖ,
MGRP+AGRP=GRP+5+5log10ϖ, and
MW3+AW3=W3+5+5log10ϖ. They are based on the Gaia DR2
parallaxes ϖ, photometry in the GBP, GRP bands, and WISE
photometry in the W3 band. We created a complete sample of 101810
giants in a space cylinder with the radius 700pc around the Sun, up to
|Z|<1800pc along the Z Galactic coordinate.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 101810 The main data for the selected sample
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 30 F10.6 deg RAdeg Right ascension (ICRS) at Ep=2015.5
32- 41 F10.6 deg DEdeg Declination (ICRS) at Ep=2015.5
43- 47 F5.2 mas plx Gaia DR2 parrallax
49- 52 F4.2 mas e_plx Error on plx
54- 63 F10.6 deg GLON Galactic longitude
65- 74 F10.6 deg GLAT Galactic latitude
76- 82 F7.2 pc rest Distance from Bailer-Jones et al.
(2018AJ....156...58B 2018AJ....156...58B, Cat. I/347)
84- 89 F6.3 mag BPmag Gaia DR2 BP-band magnitude
91- 96 F6.3 mag RPmag Gaia DR2 RP-band magnitude
98- 102 F5.3 mag W3mag AllWISE W3-band (12um) magnitude
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History:
From electronic version of the journal
References:
Gontcharov & Mosenkov, Paper II 2021MNRAS.500.2607G 2021MNRAS.500.2607G
(End) Ana Fiallos [CDS] 03-Oct-2023