J/A+A/688/A179 SPIRou spectra of 14 transiting exoplanets (Masson+, 2024)
Probing atmospheric escape through metastable He I triplet lines in 15
exoplanets observed with SPIRou.
Masson A., Vinatier S., Bezard B., Lopez-Puertas M., Lampon M., Debras F.,
Carmona A., Klein B., Artigau E., Dethier W., Pelletier S., Hood T.,
Allart R., Bourrier V., Cadieux C., Charnay B., Cowan N.B., Cook N.J.,
Delfosse X., Donati J.-F., Gu P.-G., Hebrard G., Martioli E., Moutou C.,
Venot O., Wyttenbach A.
<Astron. Astrophys. 688, A179 (2024)>
=2024A&A...688A.179M 2024A&A...688A.179M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectroscopy ;
Spectra, infrared
Keywords: instrumentation: spectrographs - methods: observational -
techniques: spectroscopic - planets and satellites: atmospheres -
planets and satellites: gaseous planets - infrared: planetary systems
Abstract:
For several years, the metastable helium triplet line has been
successfully used as a tracer to probe atmospheric escape in
transiting exoplanets. This absorption in the near-infrared (1083.3nm)
can be observed from the ground using high-resolution spectroscopy,
providing new constraints on the mass-loss rate and the temperature
characterizing the upper atmosphere of close-in exoplanets. The aim of
this work is to search for the He triplet signature in 15 transiting
exoplanets -- ranging from super-Earths to ultrahot Jupiters --
observed with SPIRou, a high-resolution (R∼70000) near-infrared
spectropolarimeter at the CFHT, in order to bring new constraints or
to improve existing ones regarding atmospheric escape through a
homogeneous study. We developed a full data processing and analysis
pipeline to correct for the residual telluric and stellar
contributions. We then used two different 1D models based on the
Parker-wind equations and nonlocal thermodynamic equilibrium (NLTE)
radiative transfer to interpret the observational results. We confirm
published He triplet detections for HAT-P-11 b, HD 189733 b, and
WASP-69 b. We tentatively detect the signature of escaping He in HD
209458 b, GJ 3470 b, and WASP-76 b. We report new constraints on the
mass-loss rate and temperature for our three detections and set upper
limits for the tentative and nondetections. We notably report improved
constraints on the mass-loss rate and temperature of the escaping gas
for TOI-1807 b, and report a nondetection for the debated atmospheric
escape in GJ 1214 b. We also conducted the first search for the He
signature in GJ 486 b since its discovery and report a nondetection of
the He triplet. Finally, we studied the impact of important model
assumptions on our retrieved parameters, notably the limitations of 1D
models and the influence of the H/He ratio on the derived constraints.
Description:
1D spectra of 14 transiting exoplanets. We provide the reduced data
for each of the targets after the reduction process described in
Section 3 in the paper. These data correspond to what is shown in
Figure 4 in the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 50 14 List of studied sources
sp/* . 14 Individual spectra
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Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name
14- 15 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
20- 23 F4.1 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 35 F4.1 arcsec DEs Declination (J2000)
37- 50 A14 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file (#): sp/*
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Bytes Format Units Label Explanations
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1- 9 F9.3 0.1nm lambda Wavelength in vacuum, spanning the full SPIRou
order #71 (spanning the 1069.3-1095.4nm range)
17- 22 F6.4 --- NFlux Normalized flux
25- 30 F6.4 --- e_NFlux 1-sigma error on normalised flux (1)
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Note (1): estimated from the temporal variance of the reduced data before
averaging them along the time axis (see Appendix F.1 in the paper).
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Acknowledgements:
Adrien Masson, adrien.masson[at]obspm.fr
(End) Patricia Vannier [CDS] 13-Jun-2024