A5068530877- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- SAS software applications and methods
- Geophysics and Gravity Measurements
- Advanced Chemical Physics Studies
- Advanced Data Processing Techniques
- Atomic and Molecular Physics
- Astrophysical Phenomena and Observations
- Big Data Technologies and Applications
- Spacecraft and Cryogenic Technologies
- Galaxies: Formation, Evolution, Phenomena
- Pharmacological Effects and Assays
Max Planck Institute for Extraterrestrial Physics
2022-2023
University of Copenhagen
2017-2022
Natural History Museum Aarhus
2017-2018
Using zoom-simulations carried out with the adaptive mesh-refinement code RAMSES a dynamic range of up to $2^{27} \approx 1.34 \times 10^8$ we investigate accretion profiles around six stars embedded in different environments inside (40 pc)$^3$ giant molecular cloud, role mass infall and disc instabilities on profile, thus luminosity forming protostar. Our results show that environment which protostar is determines overall profile Infall circumstellar may trigger gravitational at distances...
Abstract MHD models and the observation of accretion streamers confirmed that protostars can undergo late events after initial collapse phase. To provide better constraints, we study evolution stellar masses in simulations a 4 pc $$^{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow/><mml:mn>3</mml:mn></mml:msup></mml:math> molecular cloud. Tracer particles allow us to accurately follow trajectory accreting material for all thereby constrain reservoir stars....
Hertzsprung–Russell diagrams of star-forming regions show a large luminosity spread. This is incompatible with well-defined isochrones based on classic non-accreting protostellar evolution models. Protostars do not evolve in isolation their environment, but grow through accretion gas. In addition, while an age can be defined for region, the ages individual stars region will vary. We how combined effect spread, consequence sustained star formation molecular cloud, and time-varying protostars...
Context. Establishing the origin of water D/H ratio in Solar System is central to our understanding chemical trail during star and planet formation process. Recent modeling suggests that comparisons D 2 O/HDO HDO/H O ratios are a powerful way trace evolution and, particular, determine whether inherited from molecular cloud or established locally. Aims. We seek column density derive warm region toward low-mass Class 0 sources B335 L483. The results compared with astrochemical models previous...
Observations of molecular lines are a key tool to determine the main physical properties prestellar cores. However, not all information is retained in observational process or easily interpretable, especially when larger number and spectral features involved. We present methodology link synthetic spectra with actual simulated models (i.e., their properties), particular, where resides spectra. employ 1D gravitational collapse model advanced thermochemistry, from which we generate then use...
Context. How water is delivered to planetary systems a central question in astrochemistry. The deuterium fractionation of can serve as tracer for the chemical and physical evolution during star formation constrain origin Solar System bodies. Aims. aim determine HDO/H 2 O ratio inner warm gas toward three low-mass Class 0 protostars selected be isolated cores, i.e., not associated with any cloud complexes. Previous sources which have been established were all part larger star-forming...
Deuteration is a crucial tool to understand the complexity of interstellar chemical processes, especially when they involve interplay gas-phase and grain-surface chemistry. In case multiple deuteration, comparing observation with results modelling particularly effective study how molecules are inherited in different stages within process star planet formation. We aim D/ H ratio H2CS across prototypical pre-stellar core L1544. This allows us test current gas-dust models involving sulfur dense...
Pre-stellar cores represent the earliest stage of star- and planet-formation process. By characterizing physical chemical structure these we can establish initial conditions for star planet formation determine to what degree composition pre-stellar is inherited later stages. A 3D MHD model a core embedded in dynamic star-forming cloud post-processed using sequentially continuum radiative transfer, gas-grain model, line-radiative transfer model. Results are analyzed compared observations...
Abstract The water snowline location in protostellar envelopes provides crucial information about the thermal structure and mass accretion process as it can inform occurrence of recent (≲1000 yr) bursts. In addition, ability to image emission makes these sources excellent laboratories test indirect tracers such H 13 CO + . We study five Perseus using a suite molecular-line observations taken with Atacama Large Millimeter/submillimeter Array (ALMA) at ∼0.″2−0.″7 (60–210 au) resolution. B1-c...
Recent observations of the HDO/H$_2$O ratio toward protostars in isolated and clustered environments show an apparent dichotomy, where sources higher D/H ratios than counterparts. Establishing which physical chemical processes create this differentiation can provide insights into evolution water during star formation diversity process young planetary systems. Methods: The is modeled using 3D physicochemical models a dynamic star-forming environment. protostellar collapse described by tracer...
Context . Nitrogen fractionation is a powerful tracer of the chemical evolution during star and planet formation. It requires robust determinations nitrogen across different evolutionary stages. Aims We aim to determine 14 N/ 15 N 12 C/ 13 C ratios for HCN in six starless prestellar cores compare results between direct method using radiative transfer modeling indirect double isotope method, assuming fixed ratio. Methods. present IRAM observations 1–0, 3–2, HC 1–0 H CN transitions toward...
The water snowline location in protostellar envelopes provides crucial information about the thermal structure and mass accretion process as it can inform occurrence of recent ($\lesssim$1,000 yr) bursts. In addition, ability to image emission makes these sources excellent laboratories test indirect tracers such H$^{13}$CO$^+$. We study five Perseus using a suite molecular line observations taken with Atacama Large Millimeter/submillimeter Array (ALMA) at...