ﻻ يوجد ملخص باللغة العربية
Scale-invariant morphology parameters applied to atomic hydrogen maps (HI) of galaxies can be used to quantify the effects of tidal interaction or star-formation on the ISM. Here we apply these parameters, Concentration, Asymmetry, Smoothness, Gini, M20, and the GM parameter, to two public surveys of nearby dwarf galaxies, the VLA-ANGST and LITTLE-THINGS survey, to explore whether tidal interaction or the ongoing or past star-formation is a dominant force shaping the HI disk of these dwarfs. Previously, HI morphological criteria were identified for ongoing spiral-spiral interactions. When we apply these to the Irregular dwarf population, they either select almost all or none of the population. We find that only the Asymmetry-based criteria can be used to identify very isolated dwarfs (i.e., these have a low tidal indication). Otherwise, there is little or no relation between the level of tidal interaction and the HI morphology. We compare the HI morphology to three star-formation rates based on either Halpha, FUV or the resolved stellar population, probing different star-formation time-scales. The HI morphology parameters that trace the inequality of the distribution, the Gini, GM, and M20 parameters, correlate weakly with all these star-formation rates. This is in line with the picture that local physics dominates the ISM appearance and not tidal effects. Finally, we compare the SDSS measures of star-formation and stellar mass to the HI morphological parameters for all four HI surveys. In the two lower-resolution HI surveys (12), there is no relation between star-formation measures and HI morphology. The morphology of the two high-resolution HI surveys (6), the Asymmetry, Smoothness, Gini, M20, and GM, do show a link to the total star-formation, but a weak one.
We explore the quantified morphology of atomic hydrogen (HI) disks in the Virgo cluster. These galaxies display a wealth of phenomena in their Hi morphology, e.g., tails, truncation and warps. These morphological disturbances are related to the ram-p
Major mergers of disk galaxies are thought to be a substantial driver in galaxy evolution. To trace the fraction and the rate galaxies are in mergers over cosmic times, several observational techniques, including morphological selection criteria, hav
The morphology of the atomic hydrogen (HI) disk of a spiral galaxy is the first component to be disturbed by a gravitational interaction such as a merger between two galaxies. We use a simple parametrisation of the morphology of HI column density map
Galaxy evolution is driven to a large extent by interactions and mergers with other galaxies and the gas in galaxies is extremely sensitive to the interactions. One method to measure such interactions uses the quantified morphology of galaxy images.
Lopsidedness of the gaseous disk of spiral galaxies is a common phenomenon in disk morphology, profile and kinematics. Simultaneously, the asymmetry of a galaxys stellar disk, in combination with other morphological parameters, has seen extensive use