Tidal break-up of binary stars at the Galactic center and its consequences (2009)
Antonini, Fabio, Faber, Joshua, Gualandris, Alessia, Merritt, David
The tidal breakup of binary star systems by the supermassive black hole (SMBH) in the center of the galaxy has been suggested as the source of both the observed sample of hypervelocity stars (HVSs)...
Perturbations of Intermediate-mass Black Holes on Stellar Orbits in the Galactic Center (2009)
Gualandris, Alessia, Merritt, David
We study the short- and long-term effects of an intermediate mass black hole (IMBH) on the orbits of stars bound to the supermassive black hole (SMBH) at the center of the Milky Way. A regularized...
Perets, Hagai B., Gualandris, Alessia, Kupi, Gabor, Merritt, David, Alexander, Tal
We use N-body simulations to study the evolution of the orbital eccentricities of stars deposited near (
Explaining the orbits of the galactic center s-stars (2009)
Merritt, David, Gualandris, Alessia
Also archived in arXiv:0812.4517 v1 Dec 24, 2008
Explaining the Orbits of the Galactic Center S-Stars (2008)
Merritt, David, Gualandris, Alessia, Mikkola, Seppo
The young stars near the supermassive black hole at the galactic center follow orbits that are nearly random in orientation and that have an approximately thermal distribution of eccentricities, N(e)...
A Hybrid N-Body Code incorporating algorithmic regularization and Post-Newtonian forces (2008)
Harfst, Stefan, Gualandris, Alessia, Merritt, David, Seppo, Mikkola
Also archived in arXiv:0803.2310 v2 Jun 26, 2008. Publishers version can be found here: http://www3.interscience.wiley.com/journal/120848326/abstract
Dynamical evolution of the young stars in the Galactic center (2008)
Perets, Hagai. B., Gualandris, Alessia, Merritt, David, Alexander, Tal
Recent observations of the Galactic center revealed a nuclear disk of young OB stars near the massive black hole (MBH), in addition to many similar outlying stars with higher eccentricities and/or...
A Parallel gravitational N-body kernel (2008)
Zwart, Simon, McMillan, Stephen, Groen, Derek, Gualandris, Alessia, Sipior, Michael, Vermin, Willem
Also archived in: arXiv:0711.0643 v1 Nov 5, 2007. Publisher's version can be found here:...
Dynamical evolution of the young stars in the Galactic center (2008)
Perets, Hagai, Gualandris, Alessia, Merritt, David, Alexander, Tal
Also archived in arXiv:0807.2340 v1 Jul 15, 2008. Proceedings from The Central Kiloparsec: Active Nuclei And Their Hosts from Ierapetra, Crete, Greece, June 4-6, 2008
Ejection of Supermassive Black Holes from Galaxy Cores (2008)
Gualandris, Alessia, Merritt, David
Also archived in: arXiv:0708.0771 v2 Jan 31 2008
INTERACTIVE N-BODY SIMULATIONS ON THE GRID: HLA VERSUS MPI (2008)
Katarzyna Rycerz, Alfredo Tirado-ramos, Alessia Gual, Marian Bubak, Peter M, ...
The grid paradigm for distributed computation provides an interesting framework for the simulation of dense stellar systems, which remains a great challenge for astrophysicists. In this work we apply...
Hyperfast pulsars as the remnants of massive stars ejected from young star clusters (2008)
Gvaramadze, Vasilii, Gualandris, Alessia, Zwart, Simon
Also archived in astro-ph/0702735 v2 Feb 25, 2008. The definitive version is available at www.blackwell-synergy.com.
Alessia Gualandris, Portegies Zwart, Dr. M. Bubak, Prof Dr. V. Icke, Dr. A. G. Hoekstra
self-gravitating systems on parallel computers Simulating self-gravitating systems on parallel computers ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit van...
Gaburov, Evghenii, Gualandris, Alessia, Zwart, Simon
Also archived in arXiv:0707.0406 v2 Dec 5, 2007
Dynamics around supermassive black holes (2007)
Gualandris, Alessia, Merritt, David
Also archived in: arXiv:0708.1196 v1 Aug 9 2007
A parallel gravitational N-body kernel (2007)
Zwart, Simon Portegies, McMillan, Steve, Groen, Derek, Gualandris, Alessia, Sipior, Michael, Vermin, Willem
We describe source code level parallelization for the {\tt kira} direct gravitational $N$-body integrator, the workhorse of the {\tt starlab} production environment for simulating dense stellar...
On the origin of hyperfast neutron stars (2007)
Gvaramadze, Vasilii, Gualandris, Alessia, Zwart, Simon
Also archived in: arXiv:0712.4230 v1 Dec 27, 2007
Dynamics around supermassive black holes (2007)
Gualandris, Alessia, Merritt, David
The dynamics of galactic nuclei reflects the presence of supermassive black holes (SBHs) in many ways. Single SBHs act as sinks, destroying a mass in stars equal to their own mass in roughly one...
Ejection of Supermassive Black Holes from Galaxy Cores (2007)
Gualandris, Alessia, Merritt, David
[Abridged] Recent numerical relativity simulations have shown that the emission of gravitational waves during the merger of two supermassive black holes (SMBHs) delivers a kick to the final hole,...
A hypervelocity star from the Large Magellanic Cloud (2006)
Gualandris, Alessia, Zwart, Simon Portegies
We study the acceleration of the star HE0437-5439, to hypervelocity and discuss its possible origin in the Large Magellanic Cloud (LMC). The star has a radial velocity of 723 km/s and is located at a...
Performance Analysis of Direct N-Body Algorithms on Special-Purpose Supercomputers (2006)
Harfst, Stefan, Gualandris, Alessia, Merritt, David, Spurzem, Rainer, Zwart, Simon Portegies, Berczik, Peter
Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N^2). Performance can be greatly enhanced via the use...
Ejection of Hyper-Velocity Stars from the Galactic Centre by Intermediate-Mass Black Holes (2006)
Baumgardt, Holger, Gualandris, Alessia, Zwart, Simon Portegies
We have performed N-body simulations of the formation of hyper-velocity stars (HVS) in the centre of the Milky Way due to inspiralling intermediate-mass black holes (IMBHs). We considered IMBHs of...
Performance Analysis of Direct N-Body Algorithms on Special-Purpose Supercomputers (2006)
Harfst, Stefan, Gualandris, Alessia, Merritt, David, Spurzem, Rainer, Zwart, Simon, Berczk, Peter
Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N^2). Performance can be greatly enhanced via the use...
Performance analysis of direct N-body algorithms on special-purpose supercomputers (2006)
Harfst, Stefan, Gualandris, Alessia, Merritt, David, Spurzem, Rainer, Zwart, Simon, Berczik, Peter
Direct-summation N-body algorithms compute the gravitational interaction between stars in an exact way and have a computational complexity of O(N^2). Performance can be greatly enhanced via the use...
Simulating self-gravitating systems on parallel computers [electronic resource] / (2006)
Proefschrift Universiteit van Amsterdam.
Simulating self-gravitating systems on parallel computers / (2006)
Proefschrift Universiteit van Amsterdam.
Simulating self-gravitating systems on parallel computers (2006)
Proefschrift Universiteit van Amsterdam.
Gualandris, Alessia, Zwart, Simon Portegies, Sipior, Michael
Hills (1988) predicted that runaway stars could be accelerated to velocities larger than 1000 km/s by dynamical encounters with the supermassive black hole (SMBH) in the Galactic center. The recently...
Gualandris, Alessia, Zwart, Simon Portegies, Tirado-Ramos, Alfredo
We discuss the performance of direct summation codes used in the simulation of astrophysical stellar systems on highly distributed architectures. These codes compute the gravitational interaction...
Has the black hole in XTE J1118+480 experienced an asymmetric natal kick? (2004)
Gualandris, Alessia, Colpi, Monica, Zwart, Simon Portegies, Possenti, Andrea
We explore the origin of the Galactic high latitude black hole X-ray binary XTE J1118+480, and in particular its birth location and the magnitude of the kick received by the black hole upon formation...
N-body simulations of stars escaping from the Orion nebula (2004)
Gualandris, Alessia, Zwart, Simon Portegies, Eggleton, Peter P.
We study the dynamical interaction in which the two single runaway stars AE Aurigae and mu Columbae and the binary iota Orionis acquired their unusually high space velocity. The two single runaways...
A search for close companions in Sco OB2 (2003)
Kouwenhoven, Thijs, Brown, Anthony, Zinnecker, Hans, Kaper, Lex, Zwart, Simon Portegies, Gualandris, Alessia
Using adaptive optics we study the binary population in the nearby OB association Scorpius OB2. We present the first results of our near-infrared adaptive optics survey among 199 (mainly) A- and...
Is NGC6752 hiding a double black hole binary in its core ? (2002)
Colpi, Monica, Gualandris, Alessia, Possenti, Andrea
NGC6752 hosts in its halo PSR J1911-5958A, a newly discovered binary millisecond pulsar which is the most distant pulsar ever known from the core of a globular cluster. Interestingly, its recycling...
Unveiling black holes ejected from globular clusters (2002)
Gualandris, Alessia, Colpi, Monica, Possenti, Andrea
Was the black hole in XTE J1118+480 ejected from a globular cluster or kicked away from the galactic disk?
Colpi, Monica, Possenti, Andrea, Gualandris, Alessia
We have investigated different scenarios for the origin of the binary millisecond pulsar PSR J1911-5958A in NGC 6752, the most distant pulsar discovered from the core of a globular cluster to date....