J/A+A/701/A51 Planetary-mass-limit VLT/SINFONI library (Palma-Bifani+, 2025)
The planetary-mass-limit VLT/SINFONI library.
Spectral extraction and atmospheric characterization via forward modeling.
Palma-Bifani P., Bonnefoy M., Chauvin G., Rojo P., Baudoz P., Charnay B.,
Denis A., Hoch K., Petrus S., Ravet M., Simonnin A., Vigan A.
<Astron. Astrophys. 701, A51 (2025)>
=2025A&A...701A..51P 2025A&A...701A..51P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectra, infrared
Keywords: planets and satellites: atmospheres -
planets and satellites: composition -
planets and satellites: formation -
planets and satellites: gaseous planets -
planets and satellites: general
Abstract:
Access to medium-resolution spectra (Rlambda∼1000-10000) at
near-infrared wavelengths of young M-L objects allows us to study
their atmospheric properties. Specifically, this approach can unveil a
rich set of molecular features related to the atmospheric chemistry
and physics.
We aim to deepen our understanding of the M-L transition on
planetary-mass companions and isolated brown dwarfs, while searching
for evidence of possible differences between these two populations of
objects. To this end, we present a set of 21 VLT/SINFONI K-band
(1.95-2.45um) observations from five archival programs at
Rlambda∼4000. We aim to measure the atmospheric properties, such as
Teff, log(g), [M/H], and C/O, and to understand the similarities and
differences between objects ranging in spectral type from M5 to L5.
We extracted the spectra of these targets with the TExTRIS code. We
modeled them using ForMoSA, a Bayesian forward modeling tool for
spectral analysis, and we explored four families of self-consistent
atmospheric models: ATMO, BT-Settl, Exo-REM, and Sonora Diamondback.
Here, we present the spectra of our targets and the derived parameters
from the atmospheric modeling process. We confirm a drop in Teff as a
function of the spectral type of more than 500 K at the M/L
transition. In addition, we report C/O measurements for three
companions, 2M 0103 AB b, AB Pic b, and CD-35 2722 b, thereby adding
to the growing list of exoplanets with measured C/O ratios.
The VLT/SINFONI Library highlights two key points. First, there is a
critical need to further investigate the discrepancies among grids of
spectra generated by self-consistent models, as these models yield
varying results and do not uniformly explore the parameter space.
Second, we do not observe any obvious discrepancies in the K-band
spectra between companions and isolated brown dwarfs, which suggests
that these super-Jupiter objects might have formed through a similar
process; however, this possibility warrants further investigation.
Description:
Our work highlights the importance of analyzing large datasets
homogeneously to gain a deeper understanding of planet forma- tion,
evolution, and the atmospheric imprints of these processes. Using
ForMoSA, we have modeled a sample of 21 young substellar companions
observed with VLT/SINFONI.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 151 21 List of fits spectra with general information
about the SINFONI Library sample from table A2
fits/* . 21 Individual fits spectra
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Name Name
18- 19 I2 h RAh Right ascension (J2000)
21- 22 I2 min RAm Right ascension (J2000)
24- 28 F5.2 s RAs Right ascension (J2000)
30 A1 --- DE- Declination sign (J2000)
31- 32 I2 deg DEd Declination (J2000)
34- 35 I2 arcmin DEm Declination (J2000)
37- 41 F5.2 arcsec DEs Declination (J2000)
43- 55 A13 --- Assoc Association
57- 61 F5.2 mas plx ?=- Parallax (1)
63- 66 F4.2 mas e_plx ? Parallax error
68- 73 F6.2 pc Dist Distance (1)
75- 79 F5.2 pc e_Dist Distance error
81- 85 F5.1 Myr Age Age
87- 90 F4.1 Myr e_Age Age error
92 A1 --- l_AV Limit flag on AV
93- 97 F5.3 mag AV Expected interstellar extinction in
the visible (2)
99-102 F4.2 mag e_AV ? Expected interstellar extinction in
the visible error
104-108 A5 --- SpType Spectral type
110-113 F4.2 --- e_SpType Spectral type error
115-151 A37 --- FileName Name of the spectrum file in subdirectory fits
--------------------------------------------------------------------------------
Note (1): Parallaxes were obtained from the Gaia DR3 data release and converted
to distances. For targets without reported parallaxes, we used the median
distance of their associated group, with a conservative uncertainty
of 50 parsecs.
Note (2): The expected interstellar extinction in the visible was measured and
kindly provided by Carine Babusiaux using the 3D extinction map from
Lallement et al. (2022A&A...661A.147L 2022A&A...661A.147L, Cat. J/A+A/661/A47) and is rounded to
two decimal places or listed as an upper limit in this table.
--------------------------------------------------------------------------------
Acknowledgements:
Paulina Palma-Bifani, paulina.palma-bifani(at)obspm.fr
(End) Patricia Vannier [CDS] 11-Jul-2025