Article (Scientific journals)
MINDS: Mid-infrared atomic and molecular hydrogen lines in the inner disk around a low-mass star
Franceschi, Riccardo; Henning, Thomas; Tabone, Benoît et al.
2024In Astronomy and Astrophysics, 687, p. 96
Peer Reviewed verified by ORBi
 

Files


Full Text
Franceschi24_MINDS_H2_lines_disk_VLMS_J160532.pdf
Publisher postprint (1.05 MB) Creative Commons License - Attribution
Download

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
accretion; accretion disks; line: identification; radiation; mechanisms: general; techniques: spectroscopic; protoplanetary disks; infrared: planetary systems
Abstract :
[en] Context. Understanding the physical conditions of circumstellar material around young stars is crucial to star and planet formation studies. In particular, very low-mass stars (M<SUB>★</SUB> < 0.2 M<SUB>⊙</SUB>) are interesting sources to characterize as they are known to host a diverse population of rocky planets. Molecular and atomic hydrogen lines can probe the properties of the circumstellar gas. <BR /> Aims: This work aims to measure the mass accretion rate, the accretion luminosity, and more generally the physical conditions of the warm emitting gas in the inner disk of the very low-mass star 2MASS-J16053215-1933159. We investigate the source mid-infrared spectrum for atomic and molecular hydrogen line emission. <BR /> Methods: We present the full James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI) Medium Resolution Spectrometer (MRS) spectrum of the protoplanetary disk around the very low-mass star 2MASS-J16053215-1933159 from the MINDS GTO program, previously shown to be abundant in hydrocarbon molecules. We analyzed the atomic and molecular hydrogen lines in this source by fitting one or multiple Gaussian profiles. We then built a rotational diagram for the H<SUB>2</SUB> lines to constrain the rotational temperature and column density of the gas. Finally, we compared the observed atomic line fluxes to predictions from two standard emission models. <BR /> Results: We identify five molecular hydrogen pure rotational lines and 16 atomic hydrogen recombination lines in the 5-20 µm spectral range. The spectrum indicates optically thin emission for both species. We use the molecular hydrogen lines to constrain the mass and temperature of the warm emitting gas. We derive a total gas mass of only 2.3 × 10<SUP>−5</SUP> M<SUB>Jup</SUB> and a temperature of 635 K for the warm H<SUB>2</SUB> gas component located in the very inner disk (r < 0.033 au), which only accounts for a small fraction of the upper limit for the disk mass from continuum observations (0.2 M<SUB>Jup</SUB>). The HI (7−6) recombination line is used to measure the mass accretion rate (4.0 × 10<SUP>−10</SUP> M<SUB>⊙</SUB> yr<SUP>−1</SUP>) and luminosity (3.1 × 10<SUP>−3</SUP> L<SUB>⊙</SUB>) onto the central source. This line falls close to the HI (11−8) line, however at the spectral resolution of JWST MIRI we managed to measure both separately. Previous studies based on Spitzer have measured the combined flux of both lines to measure accretion rates. HI recombination lines can also be used to derive the physical properties of the gas using atomic recombination models. The model predictions of the atomic line relative intensities constrain the atomic hydrogen density to about 10<SUP>9</SUP>−10<SUP>10</SUP> cm<SUP>−3</SUP> and temperatures up to 5000 K. <BR /> Conclusions: The JWST-MIRI MRS observations for the very low-mass star 2MASS-J16053215-1933159 reveal a large number of emission lines, many originating from atomic and molecular hydrogen because we are able to look into the disk warm molecular layer. Their analysis constrains the physical properties of the emitting gas and showcases the potential of JWST to deepen our understanding of the physical and chemical structure of protoplanetary disks.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Franceschi, Riccardo;  Max-Planck-Institute for Astronomy, Heidelberg
Henning, Thomas;  Max-Planck-Institute for Astronomy, Heidelberg
Tabone, Benoît;  Institut d'Astrophysique Spatiale
Perotti, Giulia;  Max-Planck-Institute for Astronomy, Heidelberg
Caratti o Garatti, Alessio;  Astronomical Observatory of Capodimonte, Dublin Institute for Advanced Studies, Ireland
Bettoni, Giulio;  Max-Planck-Institute for Extraterrestrial Physics, Garching
van Dishoeck, Ewine F.;  Leiden Observatory, Max-Planck-Institute for Extraterrestrial Physics, Garching
Kamp, Inga;  University of Groningen, Kapteyn Astronomical Institute
Absil, Olivier  ;  Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO)
Güdel, Manuel;  University of Vienna, Department of Astronomy, ETH Zurich, Department of Physics
Olofsson, Göran;  AlbaNova University Center
Waters, L. B. F. M.;  Radboud University Nijmegen, Department of Astronomy and Physics, Netherlands Institute for Space Research
Arabhavi, Aditya M.;  University of Groningen, Kapteyn Astronomical Institute
Christiaens, Valentin  ;  Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Planetary & Stellar systems Imaging Laboratory ; University of Groningen, Kapteyn Astronomical Institute
Gasman, Danny;  Katholieke University of Leuven, Astronomical Institute
Grant, Sierra L.;  Max-Planck-Institute for Extraterrestrial Physics, Garching
Jang, Hyerin;  Radboud University Nijmegen, Department of Astronomy and Physics
Rodgers-Lee, Donna;  Dublin Institute for Advanced Studies, Ireland
Samland, Matthias;  Max-Planck-Institute for Astronomy, Heidelberg
Schwarz, Kamber;  Max-Planck-Institute for Astronomy, Heidelberg
Temmink, Milou;  Leiden Observatory
Barrado, David;  Center for Astrobiology, Madrid
Boccaletti, Anthony;  Observatoire de Paris, Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique
Geers, Vincent;  Royal Observatory Edinburgh
Lagage, Pierre-Olivier;  CEA Saclay, Service d'Astrophysique
Pantin, Eric;  CEA Saclay, Service d'Astrophysique
Ray, Tom P.;  Dublin Institute for Advanced Studies, Ireland
Scheithauer, Silvia;  Max-Planck-Institute for Astronomy, Heidelberg
Vandenbussche, Bart;  Katholieke University of Leuven, Astronomical Institute
Wright, Gillian;  Royal Observatory Edinburgh
More authors (20 more) Less
Language :
English
Title :
MINDS: Mid-infrared atomic and molecular hydrogen lines in the inner disk around a low-mass star
Publication date :
02 July 2024
Journal title :
Astronomy and Astrophysics
ISSN :
0004-6361
eISSN :
1432-0746
Publisher :
EDP
Volume :
687
Pages :
A96
Peer reviewed :
Peer Reviewed verified by ORBi
European Projects :
H2020 - 832428 - Origins - From Planet-Forming Disks to Giant Planets
Funders :
ERC - European Research Council
BELSPO - Belgian Federal Science Policy Office
F.R.S.-FNRS - Fonds de la Recherche Scientifique
European Union
Commentary :
Copyright ESO 2024, published by EDP Sciences - https://www.aanda.org/articles/aa/full_html/2024/07/aa48034-23/aa48034-23.html
Available on ORBi :
since 27 December 2024

Statistics


Number of views
4 (0 by ULiège)
Number of downloads
2 (0 by ULiège)

Scopus citations®
 
3
Scopus citations®
without self-citations
2
OpenCitations
 
0
OpenAlex citations
 
2

Bibliography


Similar publications



Contact ORBi