Ingo Thies
YOU?
Author Swipe
View article: Investigating the origin of the Milky Way streams
Investigating the origin of the Milky Way streams Open
Stellar streams around the Milky Way (MW) can provide valuable insights into its history and substructure formation. Previous studies have suggested that several MW streams could have an origin related to that of the disc of satellite gala…
View article: Open Star Clusters and Their Asymmetrical Tidal Tails
Open Star Clusters and Their Asymmetrical Tidal Tails Open
Stars that evaporate from their star cluster by the energy equipartition process end up in either a leading or a trailing tidal tail. In Newtonian gravitation and for open star clusters in the solar vicinity, the tidal threshold, or práh, …
View article: The spin, expansion, and contraction of open star clusters
The spin, expansion, and contraction of open star clusters Open
Context. Empirical constraints on the internal dynamics of open clusters are important for understanding their evolution and evaporation. High-precision astrometry from Gaia DR3 is thus useful to observe aspects of the cluster dynamics. Ai…
View article: The many tensions with dark-matter based models and implications on the nature of the Universe
The many tensions with dark-matter based models and implications on the nature of the Universe Open
The current standard models of cosmology (SMoC) - specifically LCDM and warm dark matter models - served for a few decades as the basis of research in astronomy and cosmology, and have been studied extensively. However, fundamental tension…
View article: The many tensions with dark-matter based models and implications on the nature of the Universe
The many tensions with dark-matter based models and implications on the nature of the Universe Open
(Abridged) Fundamental tensions between observations and dark-matter based cosmological models have emerged. This updated review has two purposes: to explore new tensions that have arisen in recent years, compounding the unresolved tension…
View article: Degree of stochastic asymmetry in the tidal tails of star clusters
Degree of stochastic asymmetry in the tidal tails of star clusters Open
Context. Tidal tails of star clusters are commonly understood to be populated symmetrically. Recently, the analysis of Gaia data revealed large asymmetries between the leading and trailing tidal tail arms of the four open star clusters Hya…
View article: Simulations of star-forming main-sequence galaxies in Milgromian gravity
Simulations of star-forming main-sequence galaxies in Milgromian gravity Open
We conduct hydrodynamical MOND simulations of isolated disc galaxies over the stellar mass range M⋆/M⊙ = 107–1011 using the adaptive mesh refinement code phantom of ramses (por), an adaptation of the ramses code with a Milgromian gravity s…
View article: Asymmetrical tidal tails of open star clusters: stars crossing their cluster’s práh† challenge Newtonian gravitation
Asymmetrical tidal tails of open star clusters: stars crossing their cluster’s práh† challenge Newtonian gravitation Open
After their birth a significant fraction of all stars pass through the tidal threshold (práh) of their cluster of origin into the classical tidal tails. The asymmetry between the number of stars in the leading and trailing tails tests grav…
View article: 3D hydrodynamic simulations for the formation of the Local Group satellite planes
3D hydrodynamic simulations for the formation of the Local Group satellite planes Open
The existence of mutually correlated thin and rotating planes of satellite galaxies around both the Milky Way (MW) and Andromeda (M31) calls for an explanation. Previous work in Milgromian dynamics (MOND) indicated that a past MW–M31 encou…
View article: Are Disks of Satellites Comprised of Tidal Dwarf Galaxies?
Are Disks of Satellites Comprised of Tidal Dwarf Galaxies? Open
It was found that satellites of nearby galaxies can form flattened co-rotating structures called disks of satellites or planes of satellites. Their existence is not expected by the current galaxy formation simulations in the standard dark …
View article: Are disks of satellites comprised of tidal dwarf galaxies?
Are disks of satellites comprised of tidal dwarf galaxies? Open
It was found that satellites of nearby galaxies can form flattened co-rotating structures called disks of satellites or planes of satellites. Their existence is not expected by the current galaxy formation simulations in the standard dark-…
View article: Barred spiral galaxies in modified gravity theories
Barred spiral galaxies in modified gravity theories Open
When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the rati…
View article: Origin Of Tidal Structures In Modified Gravity
Origin Of Tidal Structures In Modified Gravity Open
The missing mass problem has not been solved decisively yet. Observations show that if gravity is to be modified, then the MOND theory is its excellent approximation on galactic scales. MOND suggests an adjustments of the laws of physics i…
View article: MOND simulation suggests an origin for some peculiarities in the Local Group
MOND simulation suggests an origin for some peculiarities in the Local Group Open
Context. The Milky Way (MW) and Andromeda (M 31) galaxies possess rotating planes of satellites. The formation of these planes has not been explained satisfactorily so far. It has been suggested that the MW and M 31 satellites are ancient …
View article: Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes
Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes Open
\n Context. One of the key questions of the star formation problem is whether brown dwarfs (BDs) form in the manner of stars directly from the gravitational collapse of a molecular cloud core (star-like) or whether BDs and some very low-ma…
View article: Constraints on the dynamical evolution of the galaxy group M81
Constraints on the dynamical evolution of the galaxy group M81 Open
According to the standard model of cosmology, galaxies are embedded in dark matter halos which are made of particles beyond the standard model of particle physics, thus extending the mass and the size of the visible baryonic matter by typi…
View article: Simulating disk galaxies and interactions in Milgromian dynamics
Simulating disk galaxies and interactions in Milgromian dynamics Open
Since its publication 1983, Milgromian dynamics (aka MOND) has been very successful in modeling the gravitational potential of galaxies from baryonic matter alone. However, the dynamical modeling has long been an unsolved issue. In particu…
View article: M-dwarf binaries as tracers of star and brown dwarf formation
M-dwarf binaries as tracers of star and brown dwarf formation Open
The separation distribution for M-dwarf binaries in the ASTRALUX survey is\nnarrower and peaking at smaller separations than the distribution for\nsolar-type binaries. This is often interpreted to mean that M-dwarfs constitute\na continuou…
View article: CHARACTERIZING THE BROWN DWARF FORMATION CHANNELS FROM THE INITIAL MASS FUNCTION AND BINARY-STAR DYNAMICS
CHARACTERIZING THE BROWN DWARF FORMATION CHANNELS FROM THE INITIAL MASS FUNCTION AND BINARY-STAR DYNAMICS Open
The stellar initial mass function (IMF) is a key property of stellar\npopulations. There is growing evidence that the classical star-formation\nmechanism by the direct cloud fragmentation process has difficulties\nreproducing the observed …
View article: Characterizing the brown dwarf formation channels from the IMF and binary-star dynamics
Characterizing the brown dwarf formation channels from the IMF and binary-star dynamics Open
The stellar initial mass function (IMF) is a key property of stellar populations. There is growing evidence that the classical star-formation mechanism by the direct cloud process has difficulties to reproduce the observed abundance and b…