The remnants of galaxy formation from a panoramic survey of the region around M31 (2009)
McConnachie, Alan W., Irwin, Michael J., Ibata, Rodrigo A., Dubinski, John, Widrow, Lawrence M., Martin, Nicolas F., ...
In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars...
Martin, Nicolas F., McConnachie, Alan W., Irwin, Mike, Widrow, Lawrence M., Ferguson, Annette M. N., Ibata, Rodrigo A., ...
We present the discovery of two new dwarf galaxies, Andromeda XXI and Andromeda XXII, located in the surroundings of the Andromeda and Triangulum galaxies (M31 and M33). These discoveries stem from...
Warps and Bars from the External Tidal Torques of Tumbling Dark Halos (2009)
Dubinski, John, Chakrabarty, Dalia
The dark matter halos in $\Lambda$CDM cosmological simulations are triaxial and highly flattened. In many cases, these triaxial equilibria are also tumbling slowly, typically about their short axes,...
Kim, Juhan, Park, Changbom, Gott III, J. Richard, Dubinski, John
In support of the new Sloan III survey, which will measure the baryon oscillation scale using Luminous Red Galaxies (LRG), we have run the largest N-body simulation to date using $4120^3 = 69.9$...
Anatomy of the Bar Instability in Cuspy Dark Matter Halos (2008)
Dubinski, John, Berentzen, Ingo, Shlosman, Isaac
We examine the bar instability in galactic models with an exponential disk and a cuspy dark matter (DM) halo with a Navarro-Frenk-White (NFW) cosmological density profile. We construct equilibrium...
Bars in Cuspy Dark Halos (2008)
Dubinski, John, Berentzen, Ingo, Shlosman, Isaac
We examine the bar instability in models with an exponential disk and a cuspy NFW-like dark matter (DM) halo inspired by cosmological simulations. Bar evolution is studied as a function of numerical...
Visualizing Astrophysical N-body Systems (2008)
I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic...
Spiral and Bar Instabilities Provoked by Dark Matter Satellites (2008)
Dubinski, John, Gauthier, Jean-Rene, Widrow, Larry, Nickerson, Sarah
We explore the secular dynamical evolution of an N-body model of M31 in the presence of a population of 100 dark matter satellites over 10 Gyr. The satellite population has structural and kinematic...
GRAVITAS: Portraits of a Universe in Motion (2008)
Dubinski, John, Farah, John Kameel
GRAVITAS is a self-published DVD that presents a visual and musical celebration of the beauty in a dynamic universe driven by gravity. Animations from supercomputer simulations of forming galaxies,...
Dynamical Blueprints for Galaxies (2008)
Widrow, Lawrence M., Pym, Brent, Dubinski, John
We present an axisymmetric, equilibrium model for late-type galaxies which consists of an exponential disk, a Sersic bulge, and a cuspy dark halo. The model is specified by a phase space distribution...
Intrinsic Shapes of Molecular Cloud Cores (2007)
C. E. Jones, Shantanu Basu, John Dubinski
We conduct an analysis of the shapes of molecular cloud cores using recently compiled catalogs of observed axis ratios of individual cores mapped in ammonia or through optical selection. We apply...
Substructure around M31 : Evolution and Effects (2006)
Gauthier, Jean-Rene, Dubinski, John, Widrow, Lawrence M.
We investigate the evolution of a population of 100 dark matter satellites orbiting in the gravitational potential of a realistic model of M31. We find that after 10 Gyr, seven subhalos are...
Equilibrium Disk-Bulge-Halo Models for the Milky Way and Andromeda Galaxies (2005)
Widrow, Lawrence M., Dubinski, John
We describe a new set of self-consistent, equilibrium disk galaxy models that incorporate an exponential disk, a Hernquist model bulge, an NFW halo and a central supermassive black hole. The models...
Feldmeier, John J., Mihos, J. Christopher, Morrison, Heather L., Harding, Paul, Kaib, Nathan, Dubinski, John
We report the search for intracluster light in four Abell Type II/III (non-cD) galaxy clusters: Abell 801, 1234, 1553, & 1914. We find on average that these clusters contain $\sim$ 10% of their...
Dubinski, John, Humble, Robin, Pen, Ue-Li, Loken, Chris, Martin, Peter
We describe a new 512-CPU Beowulf cluster with Teraflop performance dedicated to problems in computational astrophysics. The cluster incorporates a cubic network topology based on inexpensive...
Optimal Weak Lensing Skewness Measurements (2003)
Zhang, Tong-Jie, Pen, Ue-Li, Zhang, Pengjie, Dubinski, John
Weak lensing measurements are entering a precision era to statistically map the distribution of matter in the universe. The most common measurement has been of the variance of the projected surface...
GOTPM: A Parallel Hybrid Particle-Mesh Treecode (2003)
Dubinski, John, Kim, Juhan, Park, Changbom, Humble, Robin
We describe a parallel, cosmological N-body code based on a hybrid scheme using the particle-mesh (PM) and Barnes-Hut (BH) oct-tree algorithm. We call the algorithm GOTPM for...
Detection of dark matter Skewness in the VIRMOS-DESCART survey: Implications for \Omega_0 (2003)
Pen, Ue-Li, Zhang, Tongjie, Van Waerbeke, Ludovic, Mellier, Yannick, Zhang, Pengjie, Dubinski, John
Weak gravitational lensing provides a direct statistical measure of the dark matter distribution. The variance is easiest to measure, which constrains the degenerate product \sigma_8\Omega^0.6. The...
Intrinsic Shapes of Molecular Cloud Cores (2001)
Jones, C. E., Basu, Shantanu, Dubinski, John
We conduct an analysis of the shapes of molecular cloud cores using recently compiled catalogs of observed axis ratios of individual cores mapped in ammonia or through optical selection. We apply...
The Dynamical Evolution of Galaxies in Clusters (1999)
The evolution of galaxies is driven strongly by dynamical processes including internal instabilities, tidal interactions and mergers. The cluster environment is a useful laboratory for studying these...
Constraining Dark Halo Potentials with Tidal Tails (1999)
Dubinski, John, Mihos, J. Christopher, Hernquist, Lars
We present an extensive parameter survey to study the influence of halo mass profiles on the development of tidal tails in interacting disk galaxies. We model the galaxies using a fixed exponential...
Constraining dark halos with tidal tails (1997)
Dubinski, John, Mihos, Chris, Hernquist, Lars
Massive and extended dark halos can inhibit the formation of long tidal tails in galaxy collisions. We examine this effect using an extensive survey of simulations with different dark halo potentials...
Searching for Machos (and other Dark Matter Candidates) in a Simulated Galaxy (1997)
Widrow, Lawrence M., Dubinski, John
We conduct gravitational microlensing experiments in a galaxy taken from a cosmological N-body simulation. Hypothetical observers measure the optical depth and event rate toward hypothetical LMCs and...
The Origin of the Brightest Cluster Galaxies (1997)
Most clusters and groups of galaxies contain a giant elliptical galaxy in their centres which far outshines and outweighs normal ellipticals. The origin of these brightest cluster galaxies is...
Tidal Tales Two: The Effect of Dark Matter Halos on Tidal Tail Morphology and Kinematics (1997)
Mihos, Chris, Dubinski, John, Hernquist, Lars
We examine the effect of different dark matter halo potentials on the morphology and kinematics of tidals tails in a merger model of NGC 7252. We find that models of merging galaxies with low halo...
Dave', Romeel, Dubinski, John, Hernquist, Lars
We describe PTreeSPH, a gravity treecode combined with an SPH hydrodynamics code designed for massively parallel supercomputers having distributed memory. Our computational algorithm is based on the...
We describe a new implementation of a parallel N-body tree code. The code is load-balanced using the method of orthogonal recursive bisection to subdivide the N-body system into independent...
Using Tidal Tails to Probe Dark Matter Halos (1995)
Dubinski, John, Mihos, J. Christopher, Hernquist, Lars
We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the...
Nearly Self-Consistent Disk-Bulge-Halo Models for Galaxies (1995)
Kuijken, Konrad, Dubinski, John
We describe methods for setting up self-consistent disk-bulge-halo galaxy models. The bulge and halo distribution functions (\df) are functions of $E$ and $L_z$ only. The halo's flattening and...
TURBULENCE IN MOLECULAR CLOUDS (1995)
Dubinski, John, Narayan, Ramesh, Phillips, T. G.
We generate random Gaussian turbulent velocity fields with a Kolmogorov spectrum and use these to obtain synthetic line-of-sight velocity profiles. The profiles are found to be similar to line...
The Settling of Warped Disks in Oblate Dark Halos (1994)
Dubinski, John, Kuijken, Konrad
When a galaxy forms, the disk may initially be tilted with respect to a flattened dark halo. The misalignment between the disk and the halo is a common explanation for galactic disk warps, since in...
Self-Gravity and Dissipation in Polar Rings (1993)
Dubinski, John, Christodoulou, Dimitris
We construct models of highly-inclined (``polar'') rings in an external potential including both self--gravity and dissipation due to a drag force. We adopt the oblate spheroidal scale--free...
Lowered Evans Models: Analytic Distribution Functions of Oblate Halo Potentials (1993)
Kuijken, Konrad, Dubinski, John
We describe an analytic distribution function of a finite, oblate stellar system that is useful for the practical modelling of dark halos. The function is determined by lowering Evans's (1993)...
The Effect of Dissipation on the Shapes of Dark halos (1993)
The dissipative infall of gas during the formation of a galaxy modifies the density profile and shape of the dark halo. Gas dissipates energy radiatively and sinks to the center of the dark halo...