J/A+A/686/A25 Hot subluminous stars 500pc volume-limited sample (Dawson+, 2024)
A 500 pc volume-limited sample of hot subluminous stars.
I. Space density, scale height, and population properties.
Dawson H., Geier S., Heber U., Pelisoli I., Dorsch M., Schaffenroth V.,
Reindl N., Culpan R., Pritzkuleit M., Vos J., Soemitro A.A., Roth M.M.,
Schneider D., Uzundag M., Vuckovic M., Antunes Amaral L., Istrate A.G.,
Justham S., Ostensen R.H., Telting J.H., Djupvik A.A., Raddi R.,
Green E.M., Jeffery C.S., Kepler S.O., Munday J., Steinmetz T., Kupfer T.
<Astron. Astrophys. 686, A25 (2024)>
=2024A&A...686A..25D 2024A&A...686A..25D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, subdwarf ; Spectral types ; Photometry ; Optical ;
Parallaxes, trigonometric
Keywords: catalogs - binaries: general - Hertzsprung-Russell and C-M diagrams -
stars: statistics - subdwarfs
Abstract:
We present the first volume-limited sample of spectroscopically
confirmed hot subluminous stars out to 500pc, defined using the
accurate parallax measurements from the Gaia space mission data
release 3 (DR3). The sample comprises a total of 397 members, with 305
(∼77%) identified as hot subdwarf stars, including 83 newly discovered
systems. Of these, we observe that 178 (∼58%) are hydrogen-rich sdBs,
65 are sdOBs (∼21%), 32 are sdOs (∼11%), and 30 are He-sdO/Bs (∼10%).
Among them, 48 (∼16%) exhibit an infrared excess in their spectral
energy distribution fits, suggesting a composite binary system. The
hot subdwarf population is estimated to be 90% complete, assuming that
most missing systems are these composite binaries located within the
main sequence (MS) in the Gaia colour-magnitude diagram (CMD). The
remaining sources in the sample include cataclysmic variables (CVs),
blue horizontal branch stars (BHBs), hot white dwarfs (WDs), and MS
stars. We derived the mid-plane density ρ0 and scale height hz
for the non-composite hot subdwarf star population using a hyperbolic
sechant profile (sech2). The best-fit values are
ρ0=5.17±0.33*10-7stars/pc3 and hz=281±62pc. When
accounting for the composite-colour hot subdwarfs and their estimated
completeness, the mid-plane density increases to
ρ0=6.15+1.16-0.53*10-7stars/pc3. This corrected space
density is an order of magnitude lower than predicted by population
synthesis studies, supporting previous observational estimates.
Description:
Here we present a spectroscopically complete 500pc volume-limited
sample of hot subluminous stars using data from Gaia EDR3 (Gaia
Collaboration, 2021A&A...649A...1G 2021A&A...649A...1G, Cat. I/350). Spectroscopic classes
are given for all sources in this sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 111 48 500pc sample of composite hot subdwarf stars from
Gaia DR3 ad identified through IR excess in
their SED fits, sorted by increasing distance
tablea2.dat 119 257 500pc sample of non-composite hot subdwarf stars
from Gaia DR3, sorted by increasing distance
tablea3.dat 83 92 Other underluminous objects
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Name Name of object
24- 31 F8.4 deg RAdeg Right ascension (J2000)
33- 40 F8.4 deg DEdeg Declination (J2000)
42- 53 A12 --- Class Spectral classification
54- 57 A4 --- n_Class Note on Class (1)
59- 63 F5.2 mag Gmag Apparent Gaia G magnitude
65- 69 F5.2 mag BP-RP Gaia BP-RP colour index
71- 74 F4.2 mag Stilism E(B-V) Extinction (Stilism)
76- 80 F5.3 mas plx Gaia parallax
82- 86 F5.3 mas e_plx Gaia parallax error
88- 91 F4.2 --- RUWE Gaia RUWE
93-111 A19 --- Ref Literature reference (TW (This Work):
Spectroscopically identified or reclassified
in this work)
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Note (1): Note as follows:
(TW) = Previously known hot subdwarf system, but with a newly identified
cool MS companion.
* = Previously known systems manually added to the sample. Companion
spectral classes are derived from our SED based effective temperature
estimates using the calibration given in Allen2000asqu.book.....C.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Name of object
27- 34 F8.4 deg RAdeg Right ascension (J2000)
36- 43 F8.4 deg DEdeg Declination (J2000)
45- 59 A15 --- Class Spectral classification
61- 65 F5.2 mag Gmag Apparent Gaia G magnitude
67- 71 F5.2 mag BP-RP Gaia BP-RP colour index
73- 76 F4.2 mag Stilism E(B-V) Extinction (Stilism)
78- 81 F4.2 mag E(44-55) Extinction (SED fits)
83- 88 F6.3 mas plx Gaia parallax
90- 94 F5.3 mas e_plx Gaia parallax error
96- 99 F4.2 --- RUWE Gaia RUWE
101-119 A19 --- Ref Literature reference (TW (This Work):
Spectroscopically identified or reclassified
in this work)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Name of object
25- 32 F8.4 deg RAdeg Right ascension (J2000)
34- 41 F8.4 deg DEdeg Declination (J2000)
43- 63 A21 --- Class Spectral classification (1)
65- 83 A19 --- Ref Literature reference (TW (This Work):
Spectroscopically identified or
reclassified in this work)
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Note (1): - for candidates that have been removed from the sample as they either
possess poor astrometry or are too bright to be genuine hot subdwarfs
(see paper)
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Acknowledgements:
Harry Dawson, hdawson(at)uni-potsdam.de
(End) Patricia Vannier [CDS] 21-Mar-2024