Related papers: Could Segue 1 be a destroyed star cluster? - a dyn…
Aims: We present the first measurement of the proper motion and orbit of the very distant and intriguing globular cluster NCG 2419. Methods: We have combined data from HST and Gaia DR1 to derive the relative proper motions of stars in the…
We address the nature and origin of a spiral disk at the center of NGC 1275, the giant elliptical galaxy at the center of the Perseus cluster, that spans a radius of $\sim$$5\,\rm kpc$. By comparing stellar absorption lines measured in…
We studied the gravitational collapse of a warm (~8000 K) primordial-gas cloud as a candidate progenitor for a supermassive star (SMS; >10^5 Msun) using a three-dimensional hydrodynamical simulation, including all the relevant cooling…
A cosmological zoom-in simulation which develops into a Milky Way-like halo is started at redshift 7. The initial dark matter distribution is seeded with dense star clusters, median mass $5\times 10^5 M_\sun$, placed in the largest…
Globular clusters are often assumed to be good tracers of major star formation episodes in their host galaxies. While observations over the past 2 decades have confirmed the presence of young objects with globular cluster-like properties in…
Owing to sparse spectroscopic observations, the classification of faint satellites as either dark matter-dominated dwarf galaxies or self-gravitating star clusters remains unresolved. The recently discovered Ursa Major III/UNIONS 1…
We present a search for new members of the 300 km s$^{-1}$ stream (300S) near the dwarf galaxy Segue 1 using wide-field survey data. We identify 11 previously unknown bright stream members in the APOGEE-2 and SEGUE-1 and 2 spectroscopic…
We examine the mass-dependence of the velocity dispersion of stars in the young cluster NGC 6530 to better understand how it formed. Using a large sample of members we find that the proper motion velocity dispersion increases with stellar…
Our recently completed one billion particle Via Lactea II simulation of a Milky Way-sized dark matter halo resolves over 50,000 gravitationally bound clumps orbiting today within the virialized region of the main host. About 2,300 of these…
We use a novel technique to simulate the growth of the most massive progenitor of a protocluster region from redshift z~80, when its mass was about 10 Msun until the present day. Our nested sequence of N-body resimulations allows us to…
We present high resolution (0.2", 1000 AU) 1.3 mm ALMA observations of massive infrared dark cloud clump, G028.37+00.07-C1, thought to harbor the early stages of massive star formation. Using $\rm N_2D^+$(3-2) we resolve the previously…
We report a promising candidate for a distant supercluster at z $\sim 1.1$ in the Dark Energy Survey Science Verification data. We examine smoothed semi-3D galaxy density maps in various photo-z slices. Among several overdense regions, in…
The earliest phases of massive star formation in clusters are still poorly understood. Here, we test the hypothesis for high-mass star formation proposed in our earlier paper (Peretto et al. 2006). In order to confirm the physical validity…
We have constructed a series of non-rotating quasi-hydrostatic evolutionary models for the M2 Iab supergiant Betelgeuse ($\alpha~Orionis$). Our models are constrained by multiple observed values for the temperature, luminosity, surface…
We present the results of a new study of mass segregation in two-component star clusters, based on a large number of numerical N-body simulations using our recently developed dynamical Monte Carlo code. Specifically, we follow the dynamical…
We simulate the formation of a metal-poor (10^-2 Zsun) stellar cluster in one of the first galaxies to form in the early Universe, specifically a high-redshift atomic cooling halo (z~14). This is the first calculation that resolves the…
Observations indicate that present-day star formation in the Milky Way disk takes place in stellar ensembles or clusters rather than in isolation. Bound, long lived stellar groups are known as open clusters. They gradually lose stars and in…
A massive young star cluster, initially embedded in its parent molecular cloud, will spiral into the Galactic Center from $\lta 30m_6^{1/2}\pc$ during the life-time of its most massive stars, if the combined total mass is $\sim…
We study the evolution of star clusters located in the outer regions of a galaxy undergoing a sudden mass loss through gas expulsion in the framework of Milgromian dynamics (MOND) by means of N-body simulations. We find that, to leave a…
Here we show an example of a young asteroid cluster located in a dynamically stable region, which was produced by partial disruption of a primitive body about 30 km in size. We estimate its age to be only 1.9 +/- 0.3 Myr, thus its…