Showing papers by "Bärbel S. Koribalski published in 2016"
TL;DR: In this paper, the authors revisited the H i size-mass relation of galaxies with a sample of more than 500 nearby galaxies covering over five orders of magnitude in H i mass and more than 10 B-band magnitudes.
Abstract: We revisit the H i size-mass relation of galaxies with a sample of more than 500 nearby galaxies covering over five orders of magnitude in H i mass and more than 10 B-band magnitudes. The relation is remarkably tight with a scatter sigma similar to 0.06 dex, or 14 per cent. The scatter does not change as a function of galaxy luminosity, H i richness or morphological type. The relation is linked to the fact that dwarf and spiral galaxies have a homogeneous radial profile of H i surface density in the outer regions when the radius is normalized by D-H i. The early-type disc galaxies typically have shallower H i radial profiles, indicating a different gas accretion history. We argue that the process of atomic-to-molecular gas conversion or star formation cannot explain the tightness of the D-H i-M-H i relation. This simple relation puts strong constraints on simulation models for galaxy formation.
186 citations
TL;DR: In this paper, the authors examined the HI-to-stellar mass ratio (HI fraction) for galaxies near filament backbones within the nearby Universe and suggested that massive galaxies accreting cold gas from the intra-filament medium that can replenish some HI gas.
Abstract: We examine the HI-to-stellar mass ratio (HI fraction) for galaxies near filament backbones within the nearby Universe ($d <$ 181 Mpc). This work uses the 6 degree Field Galaxy Survey and the Discrete Persistent Structures Extractor to define the filamentary structure of the local cosmic web. HI spectral stacking of HI Parkes all sky survey observations yields the HI fraction for filament galaxies and a field control sample. The HI fraction is measured for different stellar masses and fifth nearest neighbour projected densities ($\Sigma_{5}$) to disentangle what influences cold gas in galaxies. For galaxies with stellar masses log($M_{\star}$) $<$ 11 M$_{\odot}$ in projected densities 0 $\leq$ $\Sigma_{5}$ $<$ 3 galaxies Mpc$^{-2}$, all HI fractions of galaxies near filaments are statistically indistinguishable from the control sample. Galaxies with stellar masses log($M_{\star}$) $\geq$ 11 M$_{\odot}$ have a systematically higher HI fraction near filaments than the control sample. The greatest difference is 0.75 dex, which is 5.5$\sigma$ difference at mean projected densities of 1.45 galaxies Mpc$^{-2}$. We suggest that this is evidence for massive galaxies accreting cold gas from the intrafilament medium that can replenish some HI gas. This supports cold mode accretion where filament galaxies with a large gravitational potential can draw gas from the large-scale structure.
51 citations
TL;DR: In this paper, the authors present results from individual galaxy studies and galaxy surveys in the Local Universe with particular emphasis on the spatially resolved properties of neutral hydrogen gas, and use new 3D visualisation tools to present multi-wavelength data, aided by tilted-ring models of the warped galaxy disks.
Abstract: Here I present results from individual galaxy studies and galaxy surveys in the Local Universe with particular emphasis on the spatially resolved properties of neutral hydrogen gas. The 3D nature of the data allows detailed studies of the galaxy morphology and kinematics, their relation to local and global star formation as well as galaxy environments. I use new 3D visualisation tools to present multi-wavelength data, aided by tilted-ring models of the warped galaxy disks. Many of the algorithms and tools currently under development are essential for the exploration of upcoming large survey data, but are also highly beneficial for the analysis of current galaxy surveys.
4 citations
TL;DR: In this article, the authors highlight the giant 2X-HI disks of nearby galaxies (M 83, NGC 3621, and NGC 1512) studied as part of the Local Volume HI Survey (LVHIS), their kinematics and relation to XUV disks, signatures of tidal interactions and accretion events, the MHI - DHI relation as well as the formation of tidal dwarf galaxies.
Abstract: The outskirts of galaxies - especially the very extended HI disks of galaxies - are strongly affected by their local environment. I highlight the giant 2X-HI disks of nearby galaxies (M 83, NGC 3621, and NGC 1512), studied as part of the Local Volume HI Survey (LVHIS), their kinematics and relation to XUV disks, signatures of tidal interactions and accretion events, the MHI - DHI relation as well as the formation of tidal dwarf galaxies. - Using multi-wavelength data, I create 3D visualisations of the gas and stars in galaxies, with the shape of their warped disks obtained through kinematic modelling of their HI velocity fields.
1 citations
29 Apr 2016
TL;DR: In this article, the shape of the warped disks obtained through kinematic modelling of their Hi velocity fields is used to create 3D visualisations of the gas and stars in galaxies.
Abstract: The outskirts of galaxies — especially the very extended Hi disks of galaxies — are strongly affected by their local environment. I highlight the giant 2X-Hi disks of nearby galaxies (M 83, NGC 3621, and NGC 1512), studied as part of the Local Volume Hi Survey (LVHIS), their kinematics and relation to XUV disks, signatures of tidal interactions and accretion events, the M HI - D HI relation as well as the formation of tidal dwarf galaxies. - Using multi-wavelength data, I create 3D visualisations of the gas and stars in galaxies, with the shape of their warped disks obtained through kinematic modelling of their Hi velocity fields.