J/A+A/658/A198 CHIPS II. O stars in Trumpler 14 CHIPS-Tr14 (Rainot+, 2022)
The Carina High-contrast Imaging Project for massive Stars (CHIPS):
II. O stars in Trumpler 14.
Rainot A., Reggiani M., Sana H., Bodensteiner J., Absil O.
<Astron. Astrophys. 658, A198 (2022)>
=2022A&A...658A.198R 2022A&A...658A.198R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, double and multiple ; Stars, early-type;
Stars, O; Stars, pre-main sequence; Stars, ages; Stars, masses;
Photometry ; Optical ; Stellar distribution
Keywords: stars: massive - stars: early-type - binaries: visual -
open clusters and associations: individual: Trumpler 14 -
techniques: high angular resolution
Abstract:
Most massive stars belong to multiple systems, yet the formation
process leading to such high multiplicity remain insufficiently
understood. To help constrain the different formation scenarios that
exist, insights on the low-mass end of the companion mass function of
such stars is crucial. However, this is a challenging endeavour as
(sub-)solar mass companions at angular separations ρ below 1"
(corresponding to 1000-3000au in nearby young open clusters and OB
associations) are difficult to detect due to the large brightness
contrast with the central star. With the Carina High-contrast Imaging
Project of massive Stars (CHIPS), we aim to obtain statistically
significant constraints on the presence and properties of low-mass
companions around massive stars at a previously unreachable observing
window (Δmag≥10 at ρ≤ 1"). In this second paper in the
series, we focus on the Trumpler 14 cluster, which harbours some of
the youngest and most massive O-type stars in the Milky Way. We
obtained VLT-SPHERE observations of seven O-type objects in Trumpler
14 using the IRDIFS_EXT mode. These allow us to search for companions
at separations larger than 0.15" (∼360au) and down to magnitude
contrast >10 mag in the near-infrared. We used angular and spectral
differential imaging along with PSF fitting to detect sources and
measure their flux relative to that of the central object. We detected
211 sources with near-infrared magnitude contrast in the range of 2 to
12. The closest companion, at only 0.26", is characterised as a
1.4M☉ stars with an age of 0.6Myr, in excellent agreement with
previous age estimates for Tr14. The mass function peaks at about
0.4M☉ and presents a dearth of stars in the 0.5 to 0.8M☉
mass range compared to previous estimates of the initial mass function
in Tr14.
Description:
List of parameters of 211 detected sources with SPHERE in IRDIFS_EXT
mode around the 7 O-stars in the Trumpler 14 cluster. Target stars are
Tr14-1A, Tr14-1B, Tr14-2, Tr14-8, Tr14-9, Tr14-20 and Tr14-21. For
each target, the name, spectral type, the position, observing date and
absolute K-band magnitude are provided. Photometric and derived
measurements are also provided for individual sources.
Objects:
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RA (2000) DE Designation(s)
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10 43 57 -59 33.2 Trumpler 14 = Cl VDBH 102
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 430 239 Measured and derived parameters of all detected
sources within Tr14
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See also:
J/ApJ/549/578 : BV photometry of Trumpler 14 and 16 (Degioia-Eastwood+, 2001)
J/ApJ/589/509 : Chandra observations of Trumpler 14 and 16 (Evans+, 2003)
J/A+A/515/A26 : H and Ks photometry of Trumpler 14 (Sana+, 2010)
J/A+A/603/A81 : Trumpler 14 and 16 in the Carina nebula (Damiani+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Target name (1)
9- 17 A9 --- SpType Spectral type (1)
19- 28 F10.6 deg RAdeg Telescope Right ascension (J2000.0) (1)
30- 38 F9.5 deg DEdeg Telescope Declination (J2000.0) (1)
40- 55 F16.8 JD Obs.date Observation in Julian Date (1)
57- 61 F5.3 mag KMAG Absolute K-band magnitude (1)
63- 65 A3 --- Source Source designation within the target
(B or SNN)
67 A1 --- litSource [A-G] Source designation in the literature,
for 6 sources
69- 92 E24.18 arcsec Distrad Radial distance of source
94-117 E24.18 arcsec e_Distrad Radial distance error
119-142 E24.18 deg PA Parallactic angle of source
144-167 E24.18 deg e_PA Parallactic angle error
169-172 F4.2 mag dmagYJH ? Magnitude contrast in YJH bands
174-177 F4.2 mag e_dmagYJH ? Magnitude contrast error in YJH bands
179-202 E24.18 mag dmagK1 K1-band magnitude contrast
204-227 E24.18 mag e_dmagK1 K1-band magnitude contrast error
229-252 E24.18 mag dmagK2 K2-band magnitude contrast
254-277 E24.18 mag e_dmagK2 K2-band magnitude contrast
279-296 F18.15 mag dmagK1lim K1 magnitude contrast limit (2)
298-315 F18.15 mag dmagK2lim K2 magnitude contrast limit (2)
317-326 F10.8 --- Pspur Probability of spurious association
328-338 F11.6 [mW/m2] logL Luminosity in logarithmic scale (3)
340-351 F12.6 K T Derived temperature (3)
353-360 F8.6 Msun Mass Derived solar mass (3)
362-370 F9.6 Rsun Rad Derived solar radius (3)
372-379 F8.6 [cm/s+2] logg Derived surface gravity in
logarithmic scale (3)
381-388 F8.6 Myr Age Derived age (3)
390-398 F9.6 --- X2 chi2 result from derivation
400-406 F7.5 Msun e_Mass Negative error on Mass (3)
408-414 F7.5 Msun E_Mass Positive error on Mass (3)
416-422 F7.5 Myr e_Age Negative error on Age (3)
424-430 F7.5 Myr E_Age Positive error on Age (3)
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Note (1): Target name are
Tr14_1A, Tr14_1B, Tr14_2, Tr14_8, Tr14_9, Tr14_20 and Tr14_21.
and the SpType, positions, Obs.date and KMAG are associated to the target.
Note (2): magnitude contrast limits are computed at the same radial distance
as the source.
Note (3): log(L), T, Mass, Radius, log(g), age and errors were computed as
described in associated paper.
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Acknowledgements:
Alan Rainot, alan.rainot(at)kuleuven.be
(End) Alan Rainot [KuLeuven, Belgium], Patricia Vannier [CDS] 25-Nov-2021