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Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 au ) regions of protoplanetary disks 1 . Water plays a key role in their formation 2 – 4 , although it is yet unclear whether water molecules are formed in situ or transported from the outer disk 5 , 6 . So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks 7 , similar to PDS 70, the first system with direct confirmation of protoplanet presence 8 , 9 . Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54  au ) planet-carved gap separating an inner and outer disk 10 , 11 . Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H 2 and/or OH, and survival through water self-shielding 5 . This is also supported by the presence of CO 2 emission, another molecule sensitive to ultraviolet photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir 12 . Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.  Observations with the sensitive mid-infrared spectrometer MIRI on board JWST reveal the presence of a water vapour reservoir in the terrestrial plant-forming zone of the young planetary system PDS 70.

Carbon is an essential element for life but how much can be delivered to young planets is still an open question. The chemical characterization of planet-forming disks is a crucial step in our understanding of the diversity and habitability of exoplanets. Very low-mass stars (less than 0.2 M⊙) are interesting targets because they host a rich population of terrestrial planets. Here we present the James Webb Space Telescope detection of abundant hydrocarbons in the disk of a very low-mass star obtained as part of the Mid-InfraRed Instrument mid-INfrared Disk Survey (MINDS). In addition to very strong and broad emission from C2H2 and its 13C12CH2 isotopologue, C4H2, benzene and possibly CH4 are identified, but water, polycyclic aromatic hydrocarbons and silicate features are weak or absent. The lack of small silicate grains indicates that we can look deep down into this disk. These detections testify to an active warm hydrocarbon chemistry with a high C/O ratio larger than unity in the inner 0.1 astronomical units (AU) of this disk, perhaps due to destruction of carbonaceous grains. The exceptionally high C2H2/CO2 and C2H2/H2O column density ratios indicate that oxygen is locked up in icy pebbles and planetesimals outside the water iceline. This, in turn, will have important consequences for the composition of forming exoplanets.Highly abundant hydrocarbons in a very low-mass star’s disk are detected using the JWST. This unique chemical composition is probably due to the destruction of carbon grains, and the resulting high gaseous C/O ratio may have a profound impact on the composition of growing exoplanets.

Today, there exists a wide variety of algorithms dedicated to high-contrast imaging, especially for the detection and characterisation of exoplanet signals. These algorithms are tailored to address the very high contrast between the exoplanet signal(s), which can be more than two orders of magnitude fainter than the bright starlight residuals in coronagraphic images. The starlight residuals are inhomogeneously distributed and follow various timescales that depend on the observing conditions and on the target star brightness. Disentangling the exoplanet signals within the starlight residuals is therefore challenging, and new post-processing algorithms are striving to achieve more accurate astrophysical results. The Exoplanet Imaging Data Challenge is a community-wide effort to develop, compare and evaluate algorithms using a set of benchmark high-contrast imaging datasets. After a first phase ran in 2020 and focused on the detection capabilities of existing algorithms, the focus of this ongoing second phase is to compare the characterisation capabilities of state-of-the-art techniques. The characterisation of planetary companions is two-fold: the astrometry (estimated position with respect to the host star) and spectrophotometry (estimated contrast with respect to the host star, as a function of wavelength). The goal of this second phase is to offer a platform for the community to benchmark techniques in a fair, homogeneous and robust way, and to foster collaborations.

Intro -- 1 Einleitung -- 1.1 Einführung in die Problemstellung -- 1.2 Zielsetzung der Arbeit -- 1.3 Ansatz und Vorgehensweise -- 2 Begriffliche Grundlagen, Definitionen und Kontext -- 2.1 Der Markenname: eine Begriffsklärung -- 2.1.1 Der Begriff des Markennamens in der Sprachwissenschaft -- 2.1.2 Die Marke als Rechtsgut -- 2.1.3 Die Marke aus Marketingsicht -- 2.1.4 Die Marke als wirtschaftlicher Wert -- 2.2 Theoretischer Hintergrund im linguistischen Kontext -- 2.2.1 Markennamen im Rahmen semantischer Bedeutungstheorien -- 2.2.1.1 Passt die onomasiologische Perspektive? -- 2.2.1.2 Bezeichnungswandel bei Markennamen -- 2.2.2 Wortbildung und Onomasiologie: Zusammenfassung der Theorie-Diskussion im Kontext der Untersuchung -- 2.2.3 Wortbildung durch Wortartenwechsel -- 3 Wortbildung von Markennamen -- 3.1 Anforderungen an neue Markennamen -- 3.1.1 Sprachliche Anforderungen -- 3.1.2 Formale Anforderungen an Markennamen -- 3.2 Die Gestaltung von Markennamen (Typologien) -- 4 Die Generalisierung von Markennamen -- 4.1 Begriffsklärung -- 4.1.1 Beschreibung generalisierter Markennamen -- 4.2 Ursachen der Generalisierung von Markennamen -- 4.2.1 Sprachunabhängige Rahmenbedingungen -- 4.2.2 Sprachliche Rahmenbedingungen -- 4.3 Probleme durch die Generalisierung von Markennamen -- 4.3.1 Markenschutzrechtliche Aspekte -- 4.3.2 Markenpolitische und absatzorientierte Aspekte -- 5 Die Gebrauchsanalyse -- 5.1 Untersuchungsdesign -- 5.2 Die Ergebnisse der Gebrauchsanalyse -- 5.2.1 Identifizierte Markenverben -- 5.2.2 Wortartenwechsel von markenunabhängigen Neologismen -- 5.3 Detailanalyse der Markennamen in Verbform -- 5.3.1 Sprachliche Gemeinsamkeiten von Markenverben -- 5.3.2 Sprachunabhängige Gemeinsamkeiten als Voraussetzung für die Akzeptanz von Markenverben -- 5.3.3 Zusammenfassung der Zwischenergebnisse.

Issue Title: From Observations to Self-Consistent Modelling of the ISM in Galaxies I present a model for the formation and evolution of a massive disk galaxy, within a growing dark halo whose mass evolves according to cosmological simulations of structure formation. The galactic evolution is simulated with a new 3D chemo-dynamical code, including dark matter, stars and a multi-phase ISM. We follow the evolution from redshift z = 4.85 until the present epoch. The energy release by massive stars and supernovae prevents a rapid collapse of the baryonic matter and delays the maximum star formation until redshift z [asymptotically =] 1. The galaxy forms radially from inside-out and vertically from top-to-bottom. The feedback of stars leads to turbulent motions and large-scale flows in the ISM. As one result the galactic disk is significantly enriched by chemical elements synthesized in bulge stars.[PUBLICATION ABSTRACT]

I present a model for the formation and evolution of a massive disk galaxy, within a growing dark halo whose mass evolves according to cosmological simulations of structure formation. The galactic evolution is simulated with a new three-dimensional chemo-dynamical code, including dark matter, stars and a multi-phase ISM. We follow the evolution from redshift z= 4.85 until the present epoch. The energy release by massive stars and supernovae prevents a rapid collapse of the baryonic matter and delays the maximum star formation until redshift z [asymptotically =] 1. The galaxy forms radially from inside-out and vertically from top-to-bottom. Correspondingly, the inner halo is the oldest component, followed by the outer halo, the bar/bulge, the thick and the thin disk. The bulge in the model consists of at least two stellar subpopulations, an early collapse population and a population that formed later in the bar.[PUBLICATION ABSTRACT]

The formation of a disk galaxy within a slowly growing dark halo is simulated with a new chemo-dynamical model. The model describes the evolution of the stellar populations, the multi-phase ISM and all important interaction. I find, that the galaxy forms radially from inside-out and vertically from top-to-bottom. The derived stellar age distributions show that the inner halo is the oldest component, followed by the outer halo, the triaxial bulge, the halo-disk transition region and the disk. Despite the still idealized model, the final galaxy resembles present-day disk galaxies in many aspects. In particular, the stellar metallicity distribution in the halo of the model resembles the one of M31. The bulge in the model shows, at least two stellar subpopulations, an early collapse population and a population that formed later out of accreted disk mass. In the stellar metallicity distribution of the disk, I find a pronounced 'G-dwarf problem' which is the result of a pre-enrichment of the disk ISM with metal-rich gas from the bulge. [PUBLICATION ABSTRACT]

This study aims to characterize debris disks observed with SPHERE across multiple programs, with the goal of identifying systematic trends in disk morphology, dust mass, and grain properties as a function of stellar parameters. We analyzed a sample of 161 young stars using SPHERE observations at optical and near-IR wavelengths. Disk geometries were derived from ellipse fitting and model grids, while dust mass and properties were constrained by modified blackbody (MBB) and size distribution (SD) modeling of SEDs. The dynamical modeling was performed to assess whether the observed disk structures can be explained by the presence of unseen planets. We resolved 51 debris disks, including four new detections: HD 36968, BD-20 951, and the inner belts of HR 8799 and HD 36546. In addition, we found a second transiting giant planet in the HD 114082 system, with a radius of 1.29 \\(R_{\\rm Jup}\\) and an orbital distance of ~1 au. We identified nine multi-belt systems, with outer-to-inner belt radius ratios of \\(1.5-2\\), and found close agreement between scattered-light and millimeter-continuum belt radii. They scale weakly with stellar luminosity (\\(R_{\\rm belt} \\propto L_{\\star}^{0.11}\\)), but show steeper dependencies when separated by CO and CO\\(_2\\) freeze-out regimes. Disk fractional luminosities follow collisional decay trends, declining as \\(t_{\\rm age}^{-1.18}\\) for A and \\(t_{\\rm age}^{-0.81}\\) for F stars. The inferred dust masses span \\(10^{-5}-1\\,M_\\oplus\\) from MBB and \\(0.01-1\\,M_\\oplus\\) from SD modeling. These masses scale as \\(R_{\\rm belt}^n\\) with \\(n>2\\) in belt radius and super-linearly with stellar mass, consistent with trends seen in protoplanetary disks. Analysing correlation between disk polarized flux and IR excess, we found an offset of ~1 dex between total-intensity (HST) and polarized fluxes. A new parametric approach to estimate dust albedo and maximum polarization fraction is introduced.

High-contrast imaging surveys for exoplanet detection have shown giant planets at large separations to be rare. It is important to push towards detections at smaller separations, the part of the parameter space containing most planets. The performance of traditional methods for post-processing of pupil-stabilized observations decreases at smaller separations, due to the larger field-rotation required to displace a source on the detector in addition to the intrinsic difficulty of higher stellar contamination. We developed a method of extracting exoplanet signals that improves performance at small angular separations. A data-driven model of the temporal behavior of the systematics for each pixel can be created using reference pixels at a different position, assuming the underlying causes of the systematics are shared across multiple pixels. This is mostly true for the speckle pattern in high-contrast imaging. In our causal regression model, we simultaneously fit the model of a planet signal \"transiting\" over detector pixels and non-local reference lightcurves describing a basis of shared temporal trends of the speckle pattern to find the best fitting temporal model describing the signal. With our implementation of a spatially non-local, temporal systematics model, called TRAP, we show that it is possible to gain up to a factor of 6 in contrast at close separations (\\(<3/D\\)) compared to a model based on spatial correlations between images displaced in time. We show that better temporal sampling resulting in significantly better contrasts. At short integration times for \\(\\) Pic data, we increase the SNR of the planet by a factor of 4 compared to the spatial systematics model. Finally, we show that the temporal model can be used on unaligned data which has only been dark and flat corrected, without the need for further pre-processing.