Refereed journal articles

1. González Picos, D., Snellen, I. A. G., Landman, R., de Regt, S., Grasser, N., Birkby, J. L., Stolker, T., Koutalios, I., & Kenworthy, M. A. (2026). The carbon isotope ratio of βPic b with high-resolution spectroscopy. Astronomy & Astrophysics, 711, A87.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2026betapic,
     author = {González Picos, D. and Snellen, I. A. G. and Landman, R. and de Regt, S. and Grasser, N. and Birkby, J. L. and Stolker, T. and Koutalios, I. and Kenworthy, M. A.},
     title = {The carbon isotope ratio of $\beta$ Pic b with high-resolution spectroscopy},
     journal = {Astronomy \& Astrophysics},
     year = {2026},
     volume = {711},
     pages = {A87},
     doi = {10.1051/0004-6361/202660276},
     eprint = {2606.12401},
     archiveprefix = {arXiv},
     ads = {2026A&A...711A..87G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2026A&A...711A..87G}
   }
   

   Isotopic ratios trace the formation and evolution of planets and link their atmospheres to the chemistry of their natal protoplanetary discs. We measure 12C/13C = 58+18-15 in the atmosphere of the young super-Jupiter β Pic b from 11 nights of CRIRES+ K-band spectroscopy at the VLT.

2. González Picos, D., van der Post, T., de Regt, S., Ruffio, J.-B., Grasser, N., & Snellen, I. (2026). JWST high-contrast spectroscopy with speckle modelling: Atmospheric retrievals of the T-dwarf companion HD 19467 B. Astronomy & Astrophysics, 710, A293.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2026hd19467,
     author = {González Picos, D. and van der Post, T. and de Regt, S. and Ruffio, J.-B. and Grasser, N. and Snellen, I.},
     title = {JWST high-contrast spectroscopy with speckle modelling: Atmospheric retrievals of the T-dwarf companion HD 19467 B},
     journal = {Astronomy \& Astrophysics},
     year = {2026},
     volume = {710},
     pages = {A293},
     doi = {10.1051/0004-6361/202659296},
     eprint = {2605.02769},
     archiveprefix = {arXiv},
     ads = {2026A&A...710A.293G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2026A&A...710A.293G}
   }
   

   High-contrast, medium-resolution spectroscopy with JWST can resolve molecular and isotopic features in cool substellar atmospheres, but for close-in companions the extracted spectra can be biased by wavelength-dependent residual stellar contamination. We assess the impact of residual speckles on atmospheric inference for the T dwarf companion HD 19467 B.

3. González Picos, D., Snellen, I., & de Regt, S. (2025). Chemical evolution imprints in the rare isotopes of nearby M dwarfs. Nature Astronomy, 9, 1692.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2025natas,
     author = {González Picos, D. and Snellen, I. and de Regt, S.},
     title = {Chemical evolution imprints in the rare isotopes of nearby M dwarfs},
     journal = {Nature Astronomy},
     year = {2025},
     volume = {9},
     pages = {1692},
     doi = {10.1038/s41550-025-02641-4},
     eprint = {2508.18424},
     archiveprefix = {arXiv},
     ads = {2025NatAs...9.1692G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2025NatAs...9.1692G}
   }
   

   We measure rare carbon and oxygen isotopes in 32 nearby M dwarfs spanning a range of metallicities using high-resolution infrared spectroscopy, finding that stars with higher metal content have lower 12C/13C ratios.

4. González Picos, D., Snellen, I. A. G., de Regt, S., Landman, R., Zhang, Y., Gandhi, S., & Sánchez-López, A. (2025). The ESO SupJup Survey IV: Unveiling the carbon isotope ratio of GQ Lup B and its host star. Astronomy & Astrophysics, 693, A298.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2025supjupiv,
     author = {González Picos, D. and Snellen, I. A. G. and de Regt, S. and Landman, R. and Zhang, Y. and Gandhi, S. and Sánchez-López, A.},
     title = {The ESO SupJup Survey IV: Unveiling the carbon isotope ratio of GQ Lup B and its host star},
     journal = {Astronomy \& Astrophysics},
     year = {2025},
     volume = {693},
     pages = {A298},
     doi = {10.1051/0004-6361/202451936},
     eprint = {2501.01789},
     archiveprefix = {arXiv},
     ads = {2025A&A...693A.298G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2025A&A...693A.298G}
   }
   

   The carbon isotope ratio is a potential tracer of giant planet and brown dwarf formation. We present measurements for the GQ Lup system, hosting the K7 T Tauri star GQ Lup A and its substellar companion GQ Lup B.

5. González Picos, D., de Regt, S., Gandhi, S., Grasser, N., & Snellen, I. A. G. (2025). Disentangling the atmospheric and disc signatures of young brown dwarfs with JWST/NIRSpec. Astronomy & Astrophysics, 703, A65.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2025disc,
     author = {González Picos, D. and de Regt, S. and Gandhi, S. and Grasser, N. and Snellen, I. A. G.},
     title = {Disentangling the atmospheric and disc signatures of young brown dwarfs with JWST/NIRSpec},
     journal = {Astronomy \& Astrophysics},
     year = {2025},
     volume = {703},
     pages = {A65},
     doi = {10.1051/0004-6361/202555669},
     eprint = {2509.11694},
     archiveprefix = {arXiv},
     ads = {2025A&A...703A..65G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2025A&A...703A..65G}
   }
   

   Young brown dwarfs serve as analogues of giant planets and provide benchmarks for atmospheric and formation models. We use JWST/NIRSpec to disentangle disc and atmospheric signatures in young brown dwarfs.

6. González Picos, D., Snellen, I. A. G., de Regt, S., Landman, R., Zhang, Y., Gandhi, S., Ginski, C., Kesseli, A. Y., Mollière, P., & Stolker, T. (2024). The ESO SupJup Survey II: The ^12C/^13C ratios of three young brown dwarfs with CRIRES+. Astronomy & Astrophysics, 689, A212.

   DOI arXiv ADS BIB Abstract

   @article{gonzalezpicos2024supjupii,
     author = {González Picos, D. and Snellen, I. A. G. and de Regt, S. and Landman, R. and Zhang, Y. and Gandhi, S. and Ginski, C. and Kesseli, A. Y. and Mollière, P. and Stolker, T.},
     title = {The ESO SupJup Survey II: The $^{12}$C/$^{13}$C ratios of three young brown dwarfs with CRIRES+},
     journal = {Astronomy \& Astrophysics},
     year = {2024},
     volume = {689},
     pages = {A212},
     doi = {10.1051/0004-6361/202450028},
     eprint = {2407.07678},
     archiveprefix = {arXiv},
     ads = {2024A&A...689A.212G},
     adsurl = {https://ui.adsabs.harvard.edu/abs/2024A&A...689A.212G}
   }
   

   Young brown dwarfs exhibit atmospheric characteristics similar to those of super-Jupiters. We present 12C/13C isotope ratios for three young brown dwarfs observed with CRIRES+ as part of the ESO SupJup Survey.