L. Klarmann
A5067224096- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Space Exploration and Technology
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Atmospheric Ozone and Climate
- Advanced Semiconductor Detectors and Materials
- Scientific Measurement and Uncertainty Evaluation
- Geophysics and Gravity Measurements
- Phase Equilibria and Thermodynamics
- Superconducting and THz Device Technology
- Mechanics and Biomechanics Studies
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Advanced Fiber Laser Technologies
Max Planck Institute for Astronomy
2018-2022
Max Planck Society
2018-2021
Max Planck Innovation
2019-2021
University of Amsterdam
2015-2018
Context:Optical interferometry is at a key development stage. ESO's VLTI has established stable, robust infrastructure for long-baseline general astronomical observers. The present second-generation instruments offer wide wavelength coverage and improved performance. Their sensitivity measurement accuracy lead to data images of high reliability. Aims:We have developed MATISSE, the Multi AperTure mid-Infrared SpectroScopic Experiment, access resolution imaging in spectral domain explore...
Context. Multi-wavelength observations are indispensable in studying disk geometry and dust evolution processes protoplanetary disks. Aims. We aimed to construct a 3-dimensional model of HD 163296 capable reproducing simultaneously new the surface scattered light with SPHERE instrument thermal emission continuum midplane ALMA. want determine why SED is intermediary between otherwise well-separated group I II Herbig stars. Methods. The was modelled using Monte Carlo radiative transfer code...
The formation and the evolution of protoplanetary disks are important stages in lifetime stars. processes disk planet intrinsically linked. We spatially resolve with GRAVITY/VLTI K-band sub au-scale region 27 stars to gain statistical understanding their properties. look for correlations stellar parameters, such as luminosity, mass, temperature age. Our sample also cover a range various properties terms reprocessed flux, flared or flat morphology, gaps. developed semi-physical geometrical...
Context . The Earth is strongly depleted in carbon compared to the dust ISM, implying efficient removal of refractory before parent body formation. It has been argued that grains get rid their through oxidation and photolysis exposed upper disk layers. Aims We assess efficacy these C-removal mechanisms, while accounting for vertical radial transport grains. Methods obtained free mass budget solids by solving two 1D advection-diffusion equations, grain size distribution transport. acts on...
These protoplanetary disks in T Tauri stars play a central role star and planet formation. We spatially resolve at sub-au scales the innermost regions of sample Tauri's to better understand their morphology composition. extended our homogeneous data set 27 Herbig collected near-IR K-band observations 17 stars, spanning effective temperatures luminosities ranges ~4000-6000 K ~0.4-10 Lsun. focus on continuum emission develop semi-physical geometrical models fit interferometric search for...
We combined hydrodynamical simulations of planet-disk interactions with dust evolution models that include coagulation and fragmentation grains over a large range radii derived observational properties using radiative transfer calculations. studied the role snow line in survival inner disk transition disks. Inside line, lack ice mantles particles decreases sticking efficiency between grains. As consequence, fragment at lower collision velocities than regions beyond line. This effect allows...
Protoplanetary disks drive some of the formation process (e.g., accretion, gas dissipation, structures, etc.) stars and planets. Understanding such physical processes is one main astrophysical questions. HD 163296 an interesting young stellar object for which infrared sub-millimeter observations have shown a prominent circumstellar disk with gaps plausibly created by forming This study aims at characterizing morphology inner in multi-epoch near-infrared interferometric performed GRAVITY Very...
Context: FS Canis Majoris (FS CMa, HD 45677) is an unclassified B[e] star surrounded by inclined dust disk. The evolutionary stage of CMa still debated. Perpendicular to the circumstellar disk, a bipolar outflow was detected. Infrared aperture-synthesis imaging provides us with unique opportunity study disk structure. Aims: Our aim intensity distribution in mid-infrared L and N bands. Methods: We performed MATISSE instrument (Multi AperTure mid-Infrared SpectroScopic Experiment) low spectral...
To understand the chemical composition of planets, it is important to know region where they form in protoplanetary disks. Due its fundamental role and biological processes, carbon a key element trace. We aim identify carriers processes behind extended NIR flux observed around several Herbig stars. compare from objects PIONIER Ae/Be survey with their PAH features. HD 100453 used as benchmark case investigate influence quantum heated particles, like PAHs or very small carbonaceous grains,...
Context. VX Sgr is a cool, evolved, and luminous red star whose stellar parameters are difficult to determine, which affects its classification. Aims. We aim spatially resolve the photospheric extent as well circumstellar environment. Methods. used interferometric observations obtained with MATISSE instrument in L (3 4 {\mu}m), M (4.5 5 N (8 13 {\mu}m) bands. reconstructed monochromatic images using MIRA software. 3D radiation-hydrodynamics (RHD) simulations carried out CO5BOLD uniform disc...
Context. The inner regions of the discs high-mass young stellar objects (HMYSOs) are still poorly known due to small angular scales and high visual extinction involved. Aims. We deploy near-infrared spectro-interferometry probe gaseous disc in HMYSOs investigate origin physical characteristics CO bandhead emission (2.3–2.4 μ m). Methods. present first GRAVITY/VLTI observations at spectral (ℛ = 4000) spatial (mas) resolution overtone transitions NGC 2024 IRS 2 . Results. continuum is resolved...
Context. Carbon is one of the most abundant components in Universe. While silicates have been main focus solid phase studies protoplanetary discs (PPDs), little known about carbon content especially planet-forming regions (~0.1–10 au). Fortunately, several refractory carbonaceous species present C-H bonds (such as hydrogenated nano-diamond and amorphous well polycyclic aromatic hydrocarbons), which generate infrared (IR) features that can be used to trace reservoirs. The new mid-IR...
The formation and evolution of planetary systems impact the primordial accretion disk. HD141569 is only known pre-main sequence star characterized by a hybrid Observations probed outer-disk structure showing complex system rings interferometric observations attempted to characterize its inner 5 au region, but derived limited constraints. goal this work was explore with new high-resolution properties dust gas in internal regions HD141569. We observed on mas scales GRAVITY/VLTI near-infrared...
This paper investigates how the far-IR water ice features can be used to infer properties of disks around T Tauri stars and thermal history. We explore power future observations with SOFIA/HIRMES SPICA's proposed instrument SAFARI. A series detailed radiative transfer disk models a representative star are investigate at 45 63 micron change key properties: size, grain sizes, dust mass, settling, thickness. In addition, is devised calculate emission from warmup, direct deposit cooldown...
The ultimate astronomical observatory would be a formation flying interferometer in space, immune to atmospheric turbulence and absorption, free from telescope thermal emission, reconfigurable adjust baselines according the required angular resolution. Imagine near/mid-infrared sensitivity of JWST far-IR Herschel but with ALMA-level resolution, or imagine having precision control null host star light across 250m detect molecules atmospheres nearby exo-Earths. With no practical engineering...
51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 micron, most likely originating in the innermost regions of circumstellar disc. We aim to obtain physical and geometrical properties system by spatially resolving environment inner gaseous used second-generation VLTI/GRAVITY resolve continuum overtone emission. obtained data over 12 baselines with auxiliary telescopes derive visibilities, differential closure phases as function wavelength....
The nature of circumstellar envelopes (CSE) around Cepheids is still a matter debate. physical origin their infrared (IR) excess could be either shell ionized gas, or dust envelope, both. This study aims at constraining the geometry and IR environment long-period Cepheid $\ell$ Car (P=35.5 days) mid-IR wavelengths to understand its nature. We first use photometric observations in various bands Spitzer Space Telescope spectroscopy constrain Car. Then, we analyze VLTI/MATISSE measurements...
Context. Eta Carinae is a highly eccentric, massive binary system (semimajor axis ~15.5 au) with powerful stellar winds and phase-dependent wind-wind collision (WWC) zone. The primary star, η Car A, luminous blue variable (LBV); the secondary, B, Wolf-Rayet or O star faster but less dense wind. Aperture-synthesis imaging allows us to study mass loss from enigmatic LBV Car. Understanding LBVs crucial step toward improving our knowledge about stars their evolution. Aims. Our aim intensity...
Context. The inner few au region of planet-forming disks is a complex environment. High angular resolution observations have key role in understanding the disk structure and dynamical processes at work. Aims. In this study we aim to characterize mid-infrared brightness distribution young intermediate-mass star HD 163296, from VLTI/MATISSE observations. Methods. We use geometric models fit data. Our include smoothed ring, flat with cavity, 2D Gaussian. can account for inclination azimuthal...