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A Numerical Framework for Efficient Motion Estimation on Evolving Sphere-Like Surfaces based on Brightness and Mass Conservation Laws [article]

Lukas F. Lang
2018 arXiv   pre-print
In this work we consider brightness and mass conservation laws for motion estimation on evolving Riemannian 2-manifolds that allow for a radial parametrisation from the 2-sphere.  ...  Furthermore, for the fast and accurate estimation of the evolving sphere-like surface from scattered data we utilise surface interpolation with spatio-temporal regularisation.  ...  Acknowledgements The author thanks Pia Aanstad for kindly providing the microscopy data. Moreover, he is grateful to Peter Elbau, Christian Gerhards, and Clemens Kirisits for their helpful comments.  ... 
arXiv:1805.01006v1 fatcat:xwklmb2zmveu7jn4ndbbjerbh4

A numerical framework for efficient motion estimation on evolving sphere-like surfaces based on brightness and mass conservation laws

Lukas Lang, Apollo-University Of Cambridge Repository, Apollo-University Of Cambridge Repository
2019
In this work we consider brightness and mass conservation laws for motion estimation on evolving Riemannian 2-manifolds that allow for a radial parametrisation from the 2-sphere.  ...  Furthermore, for the fast and accurate estimation of the evolving sphere-like surface from scattered data we utilise surface interpolation with spatio-temporal regularisation.  ...  The author thanks Pia Aanstad for kindly providing the microscopy data. Moreover, he is grateful to Peter Elbau, Christian Gerhards, and Clemens Kirisits for their helpful comments.  ... 
doi:10.17863/cam.35803 fatcat:mjssiuanp5brdnoeizds2vfx64

Essence of a Climate Model [chapter]

Andrew Gettelman, Richard B. Rood
2016 Earth Systems Data and Models  
The model is developed based on everything we know about the world around us.  ...  Traditionally and historically, there are different sections in the model (sub-models, or components) for the major spheres we have discussed: atmosphere, ocean, land, cryosphere and biosphere.  ...  Tying them together with physical laws (like conservation of energy and mass) is an important constraint on climate models.  ... 
doi:10.1007/978-3-662-48959-8_4 fatcat:ej3llnisg5gsvjdonl2dldjdtm

RADIO EMISSION FROM RED-GIANT HOT JUPITERS

Yuka Fujii, David S. Spiegel, Tony Mroczkowski, Jason Nordhaus, Neil T. Zimmerman, Aaron R. Parsons, Mehrdad Mirbabayi, Nikku Madhusudhan
2016 Astrophysical Journal  
We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields.  ...  When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than  ...  D.S.S. gratefully acknowledges support from a fellowship from the AMIAS group. J.N. acknowledges support from NASA grant HST AR-12146.04-A and NSF grant AST-1102738.  ... 
doi:10.3847/0004-637x/820/2/122 fatcat:teiq4x7yrjbvfaucvxvkhm4zeu

Wind accretion onto compact objects [article]

Ileyk El Mellah
2017 arXiv   pre-print
The robustness of those simulations based on the High Performance Computing MPI-AMRVAC code is supported by the topology of the inner sonic surface, in agreement with theoretical expectations.  ...  The amplitude and stability of this gravitational beaming of the flow conditions the mass accretion rate responsible, in fine, for the X-ray luminosity of those Supergiant X-ray Binaries.  ...  The Euler equations Fluid Mechanics is based on sets of conservation laws supported by thermodynamical considerations.  ... 
arXiv:1707.09165v1 fatcat:u3mmhofwh5c6th545o4kyujdtu

Ejection of Supermassive Black Holes from Galaxy Cores

Alessia Gualandris, David Merritt
2008 Astrophysical Journal  
We estimate the time for the SMBH's oscillations to damp to the Brownian level in real galaxies and infer times as long as 1 Gyr in the brightest galaxies.  ...  We study the motion of SMBHs ejected from galaxy cores by such kicks and the effects on the stellar distribution using high-accuracy direct N-body simulations.  ...  Miller, A. Robinson and Y. Zlochower for illuminating discussions.  ... 
doi:10.1086/586877 fatcat:5sk2rrurd5ch5lttyczgzv4mju

Hot Gas in Galaxy Clusters: Theory and Simulations [article]

Michael L. Norman
2005 arXiv   pre-print
Numerical methods for simulating gas in galaxy clusters are then overviewed with an emphasis on multiscale hydrodynamic simulations of cluster ensembles.  ...  Finally, we compare various methods of measuring cluster masses using X-ray and the thermal Sunyaev-Zeldovich effect (SZE).  ...  Fig. 6 . 6 -Top left to bottom right: a) Integrated cluster mass function for three cosmologies and two redshifts; b) like a), but for integrated temperature function; c) like a) but for integrated SZ  ... 
arXiv:astro-ph/0511451v2 fatcat:jdqv6rwp7repphquuymofpvjku

Testing the Larson relations in massive clumps

A Traficante, A Duarte-Cabral, D Elia, G A Fuller, M Merello, S Molinari, N Peretto, E Schisano, A Di Giorgio
2018 Monthly notices of the Royal Astronomical Society  
A consequence of this breakdown is that the virial parameter α_vir dependence with mass (and radius) is only a function of the gravitational energy, independent of the kinetic energy of the system, and  ...  We tested the validity of the three Larson relations in a sample of 213 massive clumps selected from the Herschel Hi-GAL survey and combined with data from the MALT90 survey of 3mm emission lines.  ...  They are all located in the IV Quadrant and the vast majority of these clumps will likely form high-mass stars, based on the Kauffmann et al. (2013) and Baldeschi et al. (2017) selection criteria for  ... 
doi:10.1093/mnras/sty798 fatcat:i24qsxx6sfadhlz4mwmyzfwdvy

BAT99 126: A multiple Wolf-Rayet system in the Large Magellanic Cloud with a massive near-contact binary [article]

Soetkin Janssens, Tomer Shenar, Laurent Mahy, Pablo Marchant, Hugues Sana, Julia Bodensteiner
2020 arXiv   pre-print
The O+O binary likely went through a phase of conservative mass transfer and is currently a near-contact system.  ...  The 1.55-day O+O binary most likely will not evolve towards a BH+BH merger, but instead will merge before the components collapse to BHs.  ...  We estimated the flux of the sources by fitting their point-spread functions using a python code based on the photutils 3 package.  ... 
arXiv:2011.09484v1 fatcat:duj3mwzbljdkxmervd2qiaw6lq

Asteroid Surface Geophysics [chapter]

N. Murdoch, P. Sánchez, S. R. Schwartz, H. Miyamoto
2015 Asteroids IV  
We also discuss the state of the art in terms of experimental techniques and numerical simulations that are currently being used to investigate regolith processes occurring on small-body surfaces and that  ...  In this chapter we provide a concise summary of what the scientific community has learned so far about the surfaces of these small planetary bodies and the processes that have shaped them.  ...  ACKNOWLEDGEMENTS We would like to thank D. C. Richardson and D. J. Scheeres for their comments on our chapter and L. Staron and O. Barnouin for their very helpful reviews.  ... 
doi:10.2458/azu_uapress_9780816532131-ch039 fatcat:dr34kwu2bfcatagnllcfgv72bi

Small Solar System Bodies as granular media

D. Hestroffer, P. Sánchez, L. Staron, A. Campo Bagatin, S. Eggl, W. Losert, N. Murdoch, E. Opsomer, F. Radjai, D. C. Richardson, M. Salazar, D. J. Scheeres (+3 others)
2019 The Astronomy and Astrophysics Review  
The DART mission, for example, will test the kinetic impact technique. Even ideas for industrial exploitation have risen during the last years.  ...  In all these cases and research topics, specific knowledge of the structure and mechanical behaviour of the surface as well as the bulk of those celestial bodies is crucial.  ...  The authors would like to thank the ISSI Institute and staff for their support, and the Paris observatory for financial support.  ... 
doi:10.1007/s00159-019-0117-5 fatcat:3pysxqdisjgvzja2hfs6vx4cki

A figure of merit for black hole mass measurements with molecular gas

Timothy A. Davis
2014 Monthly notices of the Royal Astronomical Society  
Once ALMA is fully operational, we find that over 10^5 local galaxies with massive black holes will be observable, and that given sufficient surface brightness sensitivity one could measure the mass of  ...  We show that, in principle, one can estimate black-hole masses using data that only resolve scales ~2 times the formal black hole sphere of influence, and confirm this by reanalysing lower resolution observations  ...  Emsellem, R. van den Bosch and M. Sarzi for useful discussions, and the referee for suggestions that improved the paper. TAD also acknowledges the support provided by an ESO fellowship.  ... 
doi:10.1093/mnras/stu1163 fatcat:57vpyizpnnaijooyaqaf3zdxo4

WHITE DWARF MERGERS ON ADAPTIVE MESHES. I. METHODOLOGY AND CODE VERIFICATION

Max P. Katz, Michael Zingale, Alan C. Calder, F. Douglas Swesty, Ann S. Almgren, Weiqun Zhang
2016 Astrophysical Journal  
We present a set of test problems demonstrating the extent to which our software sufficiently models a system where large amounts of mass are advected on the computational domain over long timescales.  ...  Standard techniques for coupling gravitation and rotation forces to the hydrodynamics do not adequately conserve the total energy of the system for our problem, but recent advances in the literature allow  ...  the actual amount of mass on the grid instead of the mass of a perfect sphere; and, a cube of uniform density.  ... 
doi:10.3847/0004-637x/819/2/94 fatcat:p5xaktcrgncsjdcoyyrp6buxgm

Three‐dimensional MHD Simulation of the 2003 October 28 Coronal Mass Ejection: Comparison with LASCO Coronagraph Observations

Ward B. Manchester IV, Angelos Vourlidas, Gábor Tóth, Noé Lugaz, Ilia I. Roussev, Igor V. Sokolov, Tamas I. Gombosi, Darren L. De Zeeuw, Merav Opher
2008 Astrophysical Journal  
We initiate two CMEs from the same active region, one approximately a day earlier that preconditions the solar wind for the much faster CME on the 28th.  ...  We numerically model the coronal mass ejection (CME) event of October 28, 2003 that erupted from active region 10486 and propagated to Earth in less than 20 hours causing severe geomagnetic storms.  ...  O. are thankful for support provided by LWS grant NNX06AC36G. G. T. has been partially supported by the Hungarian Science Foundation (OTKA grant T047042).  ... 
doi:10.1086/590231 fatcat:3cdp7672prglvalby4f4f54l7y

OUP accepted manuscript

2019 Monthly notices of the Royal Astronomical Society  
The general paradigm consists in considering that this product is a lowered isothermal sphere (King Model).  ...  Today, Michel Henon's isochrone potential is mainly used for his integrable property in numerical simulations, but is generally not really known.  ...  field (e.g. hierarchical scenario for High Surface Brightness (HSB) galaxies (e.g  ... 
doi:10.1093/mnras/stz351 fatcat:qzlxtjajgvhdpjou6o3ydxjt2m
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