J/A+A/650/A112 Mapping hot luminous stars in the Galaxy (Zari+, 2021)
Mapping luminous hot stars in the Galaxy.
Zari E., Rix H.-W., Frankel N., Xiang M., Poggio E., Drimmel R.,
Tkachenko A.
<Astron. Astrophys. 650, A112 (2021)>
=2021A&A...650A.112Z 2021A&A...650A.112Z (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, early-type ; Stars, OB
Keywords: stars: early-type - Galaxy: structure - Galaxy: disc
Abstract:
Luminous hot stars (MKs≲0mag and Teff≳8000K) dominate the stellar
energy input to the interstellar medium (ISM) throughout cosmological
time, are used as laboratories to test theories of stellar evolution
and multiplicity, and serve as luminous tracers of star formation in
the Milky Way and other galaxies. Massive stars occupy well-defined
loci in colour-colour and colour-magnitude spaces, enabling selection
based on the combination of Gaia EDR3 astrometry and photometry and
2MASS photometry, even in the presence of substantive dust extinction.
In this paper we devise an all-sky sample of such luminous OBA-type
stars, which was designed to be complete rather than very pure,
providing targets for spectroscopic follow-up with the SDSS-V survey.
To estimate the purity and completeness of our catalogue, we derive
stellar parameters for the stars in common with LAMOST DR6 and we
compare the sample to other O and B-type star catalogues. We estimate
`astro-kinematic' distances by combining parallaxes and proper motions
with a model for the expected velocity and density distribution of
young stars; we show that this adds useful constraints on the
distances and therefore luminosities of the stars. With these
distances we map the spatial distribution of a more stringently
selected subsample across the Galactic disc, and find it to be highly
structured, with distinct over- and under-densities. The most evident
over-densities can be associated with the presumed spiral arms of the
Milky Way, in particular the Sagittarius-Carina and Scutum-Centaurus
arms. Yet, the spatial picture of the Milky Way's young disc structure
emerging in this study is complex, and suggests that most young stars
in our Galaxy (tage<tdyn) are not neatly organised into distinct
spiral arms. The combination of the comprehensive spectroscopy to come
from SDSS-V (yielding velocities, ages, etc.) with future Gaia data
releases will be crucial in order to reveal the dynamical nature of
the spiral arms themselves.
Description:
The files target_sample.fits and filtered_sample.fits contain the
target sample and filtered sample used in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
target.dat 442 988202 Target sample
target_sample.fits 2880 96081 Target sample (fits version)
filtered.dat 442 417535 Filtered sample
filtered_sample.fits 2880 40599 Filtered sample (fits version)
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
Byte-by-byte Description of file: target.dat filtered.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaEDR3 Gaia EDR3 unique source_id (source_id)
21- 35 F15.11 deg RAdeg Right ascension (ICRS) at Ep=2016.0 (ra)
37- 51 F15.11 deg DEdeg Declination (ICRS) at Ep=2016.0 (dec)
53- 66 F14.10 deg GLON Galactic longitude (l)
68- 81 F14.10 deg GLAT Galactic latitude (b)
83- 92 F10.4 mas Plx Parallax (parallax)
94-102 F9.6 mag Gmag G-band mean magnitude (photgmean_mag)
104-112 F9.6 mag BPmag ?=- Integrated BP mean magnitude
(photbpmean_mag)
114-122 F9.6 mag RPmag ?=- Integrated RP mean magnitude
(photrpmean_mag)
124-137 F14.10 --- Var sqrt(photgn_obs)/
photgmeanfluxover_error (variability)
139-144 F6.3 mag Hmag 2MASS H band (h_m)
146-151 F6.3 mag Jmag 2MASS J band (j_m)
153-158 F6.3 mag Ksmag 2MASS Ks band (ks_m)
160-173 F14.10 --- Probv1 Predicted probability of being a good
astrometric solution (Rybizki et al.,
2021MNRAS.500..397R 2021MNRAS.500..397R) (prob_v1)
175-188 F14.10 --- ZeroPoint Parallax zero point - computed following
Lindegren et al. (2020A&A...633A...1L 2020A&A...633A...1L)
(zero_point)
190-198 F9.3 mas/yr pmGLON Proper motion in Galactic longitude (pml)
200-208 F9.3 mas/yr pmGLAT Proper motion in Galactic latitude (pmb)
210-214 F5.3 mas/yr e_pmGLON Standard error of proper motion in
Galactic longitude (e_pml)
216-220 F5.3 mas/yr e_pmGLAT Standard error of proper motion in
Galactic latitude (e_pmb)
222-228 F7.4 mas/yr pmlpmbCorr Correlation between proper motion in
Galactic longitude and latitude
(pmlpmbcprr)
230-236 F7.4 --- PlxpmlCorr Correlation between parallax and proper
motion in Galactic longitude
(parallaxpmlcorr)
238-244 F7.4 --- PlxpmbCorr Correlation between parallax and proper
motion in Galactic latitude
(parallaxpmbcorr)
246-259 F14.10 kpc d50kin ?=- 50th percentile of the astro-kinematic
distance posterior distribution (d50kin)
261-274 F14.10 kpc d16kin ?=- 16th percentile of the astro-kinematic
distance posterior distribution (d16kin)
276-289 F14.10 kpc d84kin ?=- 84th percentile of the astro-kinematic
distance posterior distribution (d84kin)
291-304 F14.10 kpc dmaxpdfkin Astro-kinematic distance (mode of the
astro-kinematic distance posterior
distribution) (dmaxpdf_kin)
306-319 F14.10 kpc xkin x-component of Galactic cartesian
coordinates computed using dmaxpdf_kin
(x_kin)
321-334 F14.10 kpc ykin y-component of Galactic cartesian
coordinates computed using dmaxpdf_kin
(y_kin)
336-349 F14.10 kpc zkin z-component of Galactic cartesian
coordinates computed using dmaxpdf_kin
(z_kin)
351-364 F14.8 pc rpgeo ?=- Photo-geometric distance from
Bailer-Jones et al. (2021, Cat. I/352)
(rMedPhotogeo)
366-379 F14.8 pc B_rpgeo ?=- Upper error on the photo-geometric
distance (rHiPhotogeo)
381-394 F14.8 pc b_rpgeo ?=- Lower error on the photo_geometric
distance (rLoPhotogeo)
396-410 F15.8 pc xphotogeo ?=- x-component of Galactic cartesian
coordinates computed using rMedPhotogeo
(x_photogeo)
412-426 F15.8 pc yphotogeo ?=- y-component of Galactic cartesian
coordinates computed using rMedPhotogeo
(y_photogeo)
428-442 F15.8 pc zphotogeo ?=- z-component of Galactic cartesian
coordinates computed using rMedPhotogeo
(z_photogeo)
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Acknowledgements:
Eleonora Zari, zari(at)mpia.de
(End) Patricia Vannier [CDS] 16-Mar-2021