Photoevaporation can reproduce extended H2 emission from protoplanetary disks imaged by JWST/MIRI-MRS
Articolo
Data di Pubblicazione:
2026
Citazione:
Photoevaporation can reproduce extended H2 emission from protoplanetary disks imaged by JWST/MIRI-MRS / R. Nakatani, G. Rosotti, B. Tabone, A. Sellek. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 706:(2026 Feb), pp. A295.1-A295.28. [10.1051/0004-6361/202556740]
Abstract:
Context. Understanding the dispersal of protoplanetary disks remains a central challenge in planet formation theory. Disk winds driven by magnetohydrodynamics (MHD) and/or photoevaporation are now recognized as primary agents of dispersal. With the advent of the James Webb Space Telescope (JWST), spatially resolved imaging of these winds, particularly in H2 pure rotational lines, have become possible, revealing X-shaped morphologies and integrated fluxes of ∼10−16−10−15 erg s−1 cm−2. Aims. However, the lack of theoretical models suitable for direct comparison has limited the interpretation of these features. To address this, we present the first model of photoevaporative H2 winds tailored for direct comparison with JWST observations. Methods. Using radiation hydrodynamics simulations coupled with chemistry, we derived steady-state wind structures and postprocessed them to compute H2-level populations and line radiative transfer, including collisional excitation and spontaneous decay. Results. Our synthetic images reproduce the observed X-shaped morphology with radial extents of ≳50-300 au and semi-opening angles of ∼37°-50°, matching observations of Tau 042021 and SY Cha. While the predicted line fluxes are somewhat lower than the observed values, they remain broadly consistent for lower J transitions despite the model not being specifically tailored to these sources. Conclusions. These results suggest that photoevaporation is a viable mechanism for reproducing key features of observed H2 winds, including morphology and fluxes, though conclusive identification of the wind origin requires source-specific modeling. This conclusion challenges the reliance on geometrical structures alone to distinguish between MHD winds and photoevaporation. Based on our findings, we also discuss alternative diagnostics of photoevaporative winds. This work provides a critical first step toward interpreting spatially resolved H2 winds and motivates future modeling efforts.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
ISM: jets and outflows; photon-dominated region (PDR); protoplanetary disks
Elenco autori:
R. Nakatani, G. Rosotti, B. Tabone, A. Sellek
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