MINDS. Anatomy of a water-rich, inclined, brown dwarf disk: lack of abundant hydrocarbons

Bibliographic Details
Title: MINDS. Anatomy of a water-rich, inclined, brown dwarf disk: lack of abundant hydrocarbons
Authors: Perotti, Giulia, Kurtovic, Nicolás T., Henning, Thomas, Olofsson, Göran, Arabhavi, Aditya M., Schwarz, Kamber, Kanwar, Jayatee, van Boekel, Roy, Kamp, Inga, Pascucci, Ilaria, van Dishoeck, Ewine F., Güdel, Manuel, Lagage, Pierre-Olivier, Barrado, David, Garatti, Alessio Caratti o, Glauser, Adrian M., Lahuis, F., Christiaens, Valentin, Franceschi, Riccardo, Gasman, Danny, Grant, Sierra L., Jang, Hyerin, Kaeufer, Till, Morales-Calderón, Maria, Temmink, Milou, Vlasblom, Marissa
Publication Year: 2025
Collection: Astrophysics
Subject Terms: Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
More Details: 2MASS J04381486+2611399 (or J0438) is one of the few young brown dwarfs (BD) with a highly inclined ($i\!\sim\!70^\circ$) disk. Here we report results from JWST-MIRI MRS, HST-ACS and ALMA Band 7 observations. Despite its late spectral type (M7.25), the spectrum of J0438 resembles those of inner disks around earlier-type stars (K1-M5, T Tauri stars), with a volatile reservoir lacking hydrocarbons (except for acetylene, C$_2$H$_2$) and dominated by water. Other identified species are H$_2$, CO$_2$, HCN, [Ar$^{+}$], and [Ne$^{+}$]. The dominance of water over hydrocarbons is driven by multiple factors such as disk dynamics, young disk age, low accretion rate and possible inner disk clearing. J0438 appears highly dynamic, showing a seesaw-like variability and extended emission in H$_2 \,\,\, S$(1), $S$(3), $S$(5), [Ne$^{+}$] and CO ($J=3-2$). Interestingly, the CO emission reaches up to 400 au from the brown dwarf, suggesting ongoing infalling/outflowing activity impacting the disk chemistry. These observations underscore the combined power of JWST, HST and ALMA in characterizing the chemical diversity and dynamics of brown dwarf disks.
Comment: 30 pages, 18 figures, resubmitted the first revision to ApJ
Document Type: Working Paper
Access URL: http://arxiv.org/abs/2504.11424
Accession Number: edsarx.2504.11424
Database: arXiv
More Details
Description not available.