A5048391758- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Mechanics and Biomechanics Studies
- Sports Dynamics and Biomechanics
- Astro and Planetary Science
- Heat Transfer Mechanisms
- Particle physics theoretical and experimental studies
- Plant Water Relations and Carbon Dynamics
- Laser-Plasma Interactions and Diagnostics
- Experimental and Theoretical Physics Studies
- High-pressure geophysics and materials
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
Ludwig-Maximilians-Universität München
2010-2023
Max Planck Institute for Extraterrestrial Physics
2010-2023
Excellence Cluster Origins
2023
Leibniz Supercomputing Centre
2023
Stuttgart Observatory
2010-2018
Max Planck Society
2013
Optica
2013
Bayerische Staatssammlung für Paläontologie und Geologie
2012
University of Bonn
2006
The origin, structure and evolution of the small gas cloud, G2, is investigated, that on an orbit almost straight into Galactic central supermassive black hole (SMBH). G2 a sensitive probe hot accretion zone Sgr A*, requiring temperatures densities agree well with models captured shock-heated stellar winds. Its mass equal to critical below which cold clumps would be destroyed quickly by evaporation. also constrained fact at apocenter its sound crossing timescale was orbital timescale. Our...
We investigate the origin and fate of recently discovered gas cloud G2 close to Galactic center. Our hydrodynamical simulations focusing on dynamical evolution in combination with currently available observations favor two scenarios: a Compact Cloud which started around year 1995 Spherical Shell gas, an apocenter distance within disk(s) young stars radius few times size Cloud. The former is able explain detected signal position–velocity (PV) diagram Brγ emission 2008.5 2011.5 data. latter...
We present a high resolution simulation of an idealized model to explain the origin two young, counter-rotating, sub-parsec scale stellar disks around supermassive black hole SgrA* at Center Milky Way. In our model, collision single molecular cloud with circum-nuclear gas disk (similar one observed presently) leads multiple streams flowing towards and creating accretion angular momentum depending on ratio material. The infalling creates inclined, counter-rotating first forming roughly 1 Myr...
Feedback from massive stars is thought to play an important role in the evolution of molecular clouds. In this work we analyse effects stellar winds and supernovae (SNe) two ($\sim 10^6\,M_\odot$) giant clouds (GMCs): one gravitationally bound collapsing cloud unbound undergoing disruption by galactic shear. These have been extracted a large scale galaxy model are re-simulated at spatial resolution $\sim 0.01$ pc, including feedback winds, SNe, combined effect both. We find that stop...
We perform numerical simulations of clouds in the Galactic Centre (GC) engulfing nuclear supermassive black hole and show that this mechanism leads to formation gaseous accretion discs with properties are similar expected progenitor fragmented into observed stellar disc GC. As soon as cloud hits hole, gas opposite angular momentum relative collides downstream. This process redistribution dissipation kinetic energy, resulting a compact disc. A parameter study using 13 high-resolution...
We provide a detailed comparison between the ``gravoturbulent'' (GT) and ``global hierarchical collapse'' (GHC) models for molecular clouds star formation, their respective interpretations of observational data, features they share, suggested tests observations to discern them. Also, we clarify common misconceptions in recent literature about global nature GHC scenario, briefly discuss evolution some aspects both toward convergence. GT assumes that substructures are approximate virial...
ABSTRACT Leo T is a gas-rich dwarf located at $414\, {\rm kpc}$ (1.4Rvir) distance from the Milky Way (MW) and it currently assumed to be on its first approach. Here, we present an analysis of orbits calculated backwards in time for with our new code delorean, exploring range systematic uncertainties, e.g. MW virial mass accretion, M31 potential, cosmic expansion. We discover that tangential velocities Galactic standard-of-rest frame lower than $| \vec{u}_{\rm t}^{\rm GSR}| \le...
Abstract We investigate the future evolution of Smith Cloud by performing hydrodynamical simulations cloud impact onto gaseous Milky Way Galactic disk. assume a local origin for and thus do not include dark matter component to stabilize it. Our main focus is cloud’s influence on global star formation rate (SFR) Galaxy whether or it leads an observable event in far future. model assumes two extremes mass Cloud, upper limit 10 7 lower 6 compared observational value few . In addition, we also...
Knowing the Galactic 3D dust distribution is relevant for understanding many processes in interstellar medium and correcting astronomical observations absorption emission. Here, we aim a reconstruction of with an increase number meaningful resolution elements by orders magnitude respect to previous reconstructions, while taking advantage dust's spatial correlations inform map. We use iterative grid refinement define log-normal process spherical coordinates. This assumes fixed correlation...
The inner kiloparsec regions surrounding sub-Eddington (luminosity less than 10$^{-3}$ in Eddington units, L$_{Edd}$) supermassive black holes (BHs) often show a characteristic network of dust filaments that terminate nuclear spiral the central parsecs. Here we study role and fate these one least accreting BHs known, M31 (10$^{-7}$ using hydrodynamical simulations. evolution streamer gas particles moving under barred potential is followed from distance to After an exploratory initial...
Abstract Recently the gas and dust cloud “G2” was discovered on a highly eccentric orbit around massive black hole in Galactic center. The will bring as close 2400 Schwarzschild radii to Sgr A* beginning of 2014. With help hydrodynamical simulations using PLUTO code, we investigate possible origins fate coming years. In this proceedings article, concentrate scenario where G2 is interpreted diffuse show its detailed evolution observable position-velocity diagrams. We further elaborate problem...
Abstract We suggest a new formation mechanism for the inclined, sub-parsec scale and counterrotating stellar disks observed around central black hole in Milky Way Galactic center. The simulation of single molecular cloud crashing into circumnuclear ring gas leads to inflow multiple streams towards parsec region. time delayed arrival those forms multiple, accretion disks, with angular momentum depending on ratio material. These could then be progenitors which fragmented disks. A similar event...
The structure of protostellar cores can often be approximated by isothermal Bonnor–Ebert spheres (BES), which are stabilized an external pressure. For the typical pressure 104kB K cm−3 to 105kB found in molecular clouds, with masses below 1.5 M⊙ stable against gravitational collapse. In this paper, we analyze efficiency triggering collapse a nearby stellar wind, represents interesting scenario for low-mass star formation. We analytically derive new stability criterion BES compressed depends...
We investigate the origin and fate of recently discovered gas cloud G2 close to Galactic Center.Our hydrodynamical simulations focussing on dynamical evolution in combination with currently available observations favour two scenarios: a Compact Cloud which started around year 1995 an extended Spherical Shell gas, apocenter distance within disk(s) young stars.The former is able explain detected signal position-velocity-diagram 2008.5 2011.5 data.The latter can account for both, G2's as well...