ORCID Profile
0000-0001-5655-3729
Current Organisations
Zurich University of Applied Sciences
,
University of Zurich
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Publisher: EDP Sciences
Date: 28-02-2020
DOI: 10.1051/0004-6361/201936828
Abstract: Context. Young stars with debris disks are the most promising targets for an exoplanet search because debris indicate a successful formation of planetary bodies. Debris disks can be shaped by planets into ring structures that give valuable indications on the presence and location of planets in the disk. Aims. We performed observations of the Sco-Cen F star HD 117214 to search for planetary companions and to characterize the debris disk structure. Methods. HD 117214 was observed with the SPHERE subsystems IRDIS, IFS, and ZIMPOL at optical and near-IR wavelengths using angular and polarimetric differential imaging techniques. This provided the first images of scattered light from the debris disk with the highest spatial resolution of 25 mas and an inner working angle .1″. With the observations with IRDIS and IFS we derived detection limits for substellar companions. The geometrical parameters of the detected disk were constrained by fitting 3D models for the scattering of an optically thin dust disk. Investigating the possible origin of the disk gap, we introduced putative planets therein and modeled the planet–disk and planet–planet dynamical interactions. The obtained planetary architectures were compared with the detection limit curves. Results. The debris disk has an axisymmetric ring structure with a radius of 0.42(±0.01)″ or ~45 au and an inclination of 71(±2.5)° and exhibits a 0.4″ (~40 au) wide inner cavity. From the polarimetric data, we derive a polarized flux contrast for the disk of ( F pol ) disk / F ∗ = (3.1 ± 1.2) × 10 −4 in the RI band. Conclusions. The fractional scattered polarized flux of the disk is eight times lower than the fractional IR flux excess. This ratio is similar to the one obtained for the debris disk HIP 79977, indicating that dust radiation properties are similar for these two disks. Inside the disk cavity we achieve high-sensitivity limits on planetary companions with a mass down to ~4 M J at projected radial separations between 0.2″ and 0.4″. We can exclude stellar companions at a radial separation larger than 75 mas from the star.
Publisher: American Astronomical Society
Date: 04-2023
Abstract: We present JWST-MIRI Medium Resolution Spectrometer (MRS) spectra of the protoplanetary disk around the low-mass T Tauri star GW Lup from the MIRI mid-INfrared Disk Survey Guaranteed Time Observations program. Emission from 12 CO 2 , 13 CO 2 , H 2 O, HCN, C 2 H 2 , and OH is identified with 13 CO 2 being detected for the first time in a protoplanetary disk. We characterize the chemical and physical conditions in the inner few astronomical units of the GW Lup disk using these molecules as probes. The spectral resolution of JWST-MIRI MRS paired with high signal-to-noise data is essential to identify these species and determine their column densities and temperatures. The Q branches of these molecules, including those of hot bands, are particularly sensitive to temperature and column density. We find that the 12 CO 2 emission in the GW Lup disk is coming from optically thick emission at a temperature of ∼400 K. 13 CO 2 is optically thinner and based on a lower temperature of ∼325 K, and thus may be tracing deeper into the disk and/or a larger emitting radius than 12 CO 2 . The derived N CO 2 / N H 2 O ratio is orders of magnitude higher than previously derived for GW Lup and other targets based on Spitzer-InfraRed-Spectrograph data. This high column density ratio may be due to an inner cavity with a radius in between the H 2 O and CO 2 snowlines and/or an overall lower disk temperature. This paper demonstrates the unique ability of JWST to probe inner disk structures and chemistry through weak, previously unseen molecular features.
Publisher: American Astronomical Society
Date: 18-08-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3FD00013C
Abstract: The Mid-InfraRed Instrument/Medium-Resolution Spectrometer (MIRI/MRS) on board the James Webb Space Telescope reveals the rich and erse chemistry in the planet forming regions around Sun-like and low-mass stars.
No related grants have been discovered for Lilian Suter.