J/A+A/706/A58 Substellar IMF of Trumpler 14 open cluster (Rom+, 2026)
Substellar initial mass function of Trumpler 14.
Rom T., Moraux E., Muzic K., Andersen M., Schirmer M., Almendros-Abad V.
<Astron. Astrophys. 706, A58 (2026)>
=2026A&A...706A..58R 2026A&A...706A..58R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Associations, stellar ; Photometry, infrared
Keywords: brown dwarfs - stars: formation - stars: low-mass -
stars: luminosity function, mass function -
open clusters and associations: individual: Trumpler 14
Abstract:
Young, massive stellar clusters offer a prime setting to explore brown
dwarf (BD) formation under high densities and intense UV radiation.
Trumpler 14 (Tr 14), a ∼1Myr-old cluster located at a distance of
2.4kpc, and particularly rich in O-type stars, is an ideal target for
such a study.
Our goal is to measure the initial mass function (IMF) in the young
massive, high UV flux cluster.
We present the deepest study to date of the IMF in Tr 14 based on
Gemini Multi-Conjugate Adaptive Optics System/ Gemini-South Adaptive
Optics Imager imaging. We construct the IMF using both the Besancon
Galactic model and an observational control field from VISTA for
background correction. Completeness was assessed using artificial-star
tests and applied to the IMF derivation. Results. We estimate the IMF
down to the 20% completeness limit found at ∼0.01M☉. Using the
control field-based IMF as our primary result, we find a slope of
α=0.14±0.19for masses between 0.01-0.2M☉, and
α=1.72±0.04 for 0.2-4.5M☉, where dN/dM ∝
M-α. The low-mass slope is largely influenced by the
incompleteness-affected lowest bin; excluding it brings our results
into agreement with those from other young clusters. The resulting
median for the star-to-BD ratio in the 0.03-1M☉ mass range is
4.0, with a 95% confidence interval of 2.8-5.8.
Our analysis reveals that Tr 14 hosts a relatively flat substellar
IMF, but this is strongly influenced by the lowest-mass bin, which may
be affected by incompleteness. When that bin is excluded, the IMF
becomes consistent with those of other regions. The star-to-BD ratio
falls within the usually observed ∼3-6 range, indicating that brown
dwarfs with masses above ∼0.03M☉ form with similar efficiency
across environments. However, the relative lack of objects below this
threshold suggests that the presence of an environment with both high
stellar density and FUV flux may play a role in shaping the IMF by
suppressing the formation of BDs at masses <0.03M☉.
Description:
In this table1.dat, we list coordinates and JHKs photometry with
corresponding photometric errors in Trumpler 14. The data were
obtained with Gemini Multi-Conjugate Adaptive Optics
System/Gemini-South Adaptive Optics Imager imaging. Data images were
extracted and processed with THELI pipeline, GSAOI-specific
adaptation, astrometry and distortion correction with Gaia-EDR3. For
its part, we use SourceExtractor and PS-FEx for optimal PSF
photometry. Also, we calibrate photometry with 2MASS photometric
system using ZPs values (i.e see section 2 for more details on these
steps and on completeness through artificial star experiment, see also
section 3 for Tr 14 cluster membership and decomtaminations analysis).
Objects:
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RA (2000) DE Designation(s)
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10 43 55.99 -59 33 06.9 Tr 14 = Cl Trumpler 14
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File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 155 1578 Tr 14 stellar positions and JHKs photometry
using GSAOI imager
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See also:
J/A+A/701/A147 : Substellar population in Corona Australis (Muzic+, 2025)
J/A+A/685/A100 : Young low-mass stars population in Trumpler 14
(Itrich+, 2024)
J/A+A/677/A26 : (sub)stellar members of NGC 2244 spectra
(Almendros-Abad+, 2023)
J/A+A/668/A19 : Stellar population of Rosette Nebula and NGC 2244
(Muzic+, 2022)
J/A+A/660/A11 : Gaia distances to the Carina Nebula Complex (Goeppl+, 2022)
J/A+A/587/A153 : VISION I. VISTA Orion A Survey (Meingast+, 2016)
J/A+A/572/A116 : The VISTA Carina Nebula Survey (Preibisch+, 2014)
J/A+A/515/A26 : H and Ks photometry of Trumpler 14 (Sana+, 2010)
J/A+A/476/199 : Trumpler 14 JHKL' photometry (Ascenso+, 2007)
J/ApJ/951/139 : W filter YSOs detection. VI. sigma Orionis members
(Damian+, 2023)
J/ApJ/881/79 : Flamingos-2 near-infrared photometry in NGC 2244
(Muzic+, 2019)
J/ApJ/754/30 : VISTA IR photometry of σ Ori cluster
(Pena-Ramirez+, 2012)
J/MNRAS/486/1718 : System IMF of 25 Ori (Suarez+, 2019)
J/MNRAS/339/44 : UBVRI photometry of Tr 14, Tr 15 and Tr 16 (Tapia+, 2003)
J/AJ/143/41 : UBVIc CCD photometry of star clusters Tr14 and Tr16
(Hur+, 2012)
J/AJ/129/856 : Herbig Ae/Be stars in nearby OB associations
(Hernandez+, 2005)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC)
(IPAC-UMass, 2003-2006)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 F18.14 deg RAdeg Right Ascension (ICRS) (RA)
20- 38 F19.15 deg DEdeg Declination (ICRS) (Dec)
40- 57 F18.15 mag Jmag ? Corrected magnitude in J GSAOI photometric
filter (J)
59- 77 F19.17 mag e_Jmag ? Error of Jmag (eJ)
79- 96 F18.15 mag Hmag ? Corrected magnitude in H GSAOI photometric
filter (H)
98-116 F19.17 mag e_Hmag ? Error of Hmag (eH)
118-135 F18.15 mag Ksmag ? Corrected magnitude in Ks GSAOI photometric
filter (Ks)
137-155 F19.17 mag e_Ksmag ? Error of Ksmag (eKs)
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Acknowledgements:
Tamara Rom, trom(at)pmfst.hr
(End) Tamara Rom [Univ. of Split], Luc Trabelsi [CDS] 08-Dec-2025