scholarly journals CDM in LSB Galaxies: Toward the Optimal Halo Profile

2004 ◽  
Vol 220 ◽  
pp. 69-76 ◽  
Author(s):  
W. J. G de Blok
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Mass Density ◽  
Constant Density ◽  
Adequate Description ◽  
Density Distributions ◽  
Low Surface Brightness ◽  
Lsb Galaxies

Low Surface Brightness (LSB) galaxies are dominated by dark matter. High-resolution rotation curves suggest that their total mass-density distributions are dominated by constant density cores rather than the steep and cuspy distributions found in Cold Dark Matter (CDM) simulations. the data are best described by a model with a soft core with an inner power-law mass-density slope α = 0.2 ± 0.2. However no single universal halo profile provides an adequate description of the data. the observed mass profiles appear to be inconsistent with ACDM.

scholarly journals Gas-rich LSB Galaxies – Progenitors of Blue Compact Dwarfs?

1999 ◽  
Vol 171 ◽  
pp. 253-260 ◽  
Author(s):  
John J. Salzer ◽  
Stuart A. Norton
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Mass Density ◽  
Central Mass ◽  
Galaxy Distribution ◽  
Low Surface Brightness ◽  
Central Regions ◽  
Lsb Galaxies

AbstractWe analyze deep CCD images of nearby Blue Compact Dwarf (BCD) galaxies in an attempt to understand the nature of the progenitors which are hosting the current burst of star formation. In particular, we ask whether BCDs are hosted by normal or low-surface-brightness dI galaxies. We conclude that BCDs are in fact hosted by gas-rich galaxies which populate the extreme high-central-mass-density end of the dwarf galaxy distribution. Such galaxies are predisposed to having numerous strong bursts of star formation in their central regions. In this picture, BCDs can only occur in the minority of dwarf galaxies, rather than being a common phase experienced by all gas-rich dwarfs.

scholarly journals The Kinematics in the Cores of Low Surface Brightness Galaxies

2004 ◽  
Vol 220 ◽  
pp. 77-84
Author(s):  
R. A. Swaters ◽  
M. A. W. Verheijen ◽  
M. A. Bershady ◽  
D. R. Andersen
Keyword(s):  
Surface Brightness ◽  
Velocity Fields ◽  
Matter Density ◽  
Constant Density ◽  
Two Dimensional ◽  
Low Surface Brightness ◽  
Systematic Effects ◽  
Random Motions ◽  
Low Surface Brightness Galaxies ◽  
Lsb Galaxies

Systematic effects on HI and Hα long-slit observations make a measurement of the inner slope of the dark matter density distribution difficult to determine. Halos with constant density cores and ones with r–1 profiles both appear consistent with the data, although constant density cores generally provide better fits. High-resolution, two-dimensional velocity fields remove most of the systematic effects, yet as a result of noncircular and random motions the inner slopes still cannot be accurately measured. Halo concentration parameters provide a more useful test of cosmological models because they are more tightly constrained by observations. the concentration parameters for LSB galaxies appear consistent with, but on the low end of the distribution predicted by CDM.

scholarly journals Multiwavelength analysis of low surface brightness galaxies to study possible dark matter signature

2020 ◽  
Author(s):  
Pooja Bhattacharjee ◽  
Pratik Majumdar ◽  
Mousumi Das ◽  
Subinoy Das ◽  
Partha S Joarder ◽  
...  
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Neutral Hydrogen ◽  
Indirect Detection ◽  
Large Area ◽  
Very Large Array ◽  
Dwarf Spheroidal Galaxies ◽  
Optical Images ◽  
Low Surface Brightness ◽  
Lsb Galaxies

Abstract Low Surface Brightness (LSB) galaxies have very diffuse, low surface density stellar disks which appear faint in optical images. They are very rich in neutral hydrogen (HI) gas, which extends well beyond the stellar disks. Their extended HI rotation curves and stellar disks indicate that they have very massive dark matter (DM) halos compared to normal bright galaxies. Hence, LSB galaxies may represent valuable laboratories for the indirect detection of DM. In this paper, we search for WIMP annihilation signatures in four LSB galaxies and present an analysis of nearly nine years of data from the Fermi Large Area Telescope (LAT). Above 500 MeV, no excess emission was detected from the LSB galaxies. We obtain constraints on the DM cross-section for different annihilation channels, for both individual and stacked targets. In addition to this, we use radio data from the Very Large Array (VLA) radio telescope in order to derive DM constraints, following a multiwavelength approach. The constraints obtained from the four considered LSB galaxies are nearly 3 orders of magnitude weaker than the predicted limits for the thermal relic abundances and the combined limits achieved from Fermi-LAT observations of dwarf spheroidal galaxies. Finally, we discuss the possibility of detecting emission from LSB galaxies using the upcoming ground-based γ-ray and radio observatories, namely the Cherenkov Telescope Array (CTA) and the Square Kilometre Array (SKA).

scholarly journals The fate of LSB galaxies in clusters and the origin of the diffuse intra-cluster light

1999 ◽  
Vol 171 ◽  
pp. 229-236 ◽  
Author(s):  
Ben Moore ◽  
George Lake ◽  
Joachim Stadel ◽  
Thomas Quinn
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Large Scale ◽  
Cold Dark Matter ◽  
High Surface ◽  
Central Surface ◽  
Resolution Model ◽  
Cluster Environment ◽  
Fisher Relation ◽  
Lsb Galaxies

AbstractWe follow the evolution of disk galaxies within a cluster that forms hierarchically in a standard cold dark matter N-body simulation. At a redshift z = 0.5 we select several dark matter halos that have quiet merger histories and are about to enter the newly forming cluster environment. The halos are replaced with equilibrium high resolution model spirals that are constructed to represent luminous examples of low surface brightness (LSB) and high surface brightness (HSB) galaxies. Whilst the models have the same total luminosity, ~ L*, they have very different internal mass profiles, core radii and disk scale lengths, however they all lie at the same place on the Tully-Fisher relation. Due to their “soft” central potentials, LSB galaxies evolve dramatically under the influence of rapid encounters with substructure and strong tidal shocks from the global cluster potential - galaxy harassment. As much as 90% of the LSB disk stars are tidally stripped and congregate in large diffuse tails that trace the orbital path of the galaxy and form the diffuse intra-cluster light. The bound stellar remnants closely resemble the dwarf spheroidals (dE’s) that populate nearby clusters, with large scale lengths and low central surface brightness.

scholarly journals The universal rotation curve of low surface brightness galaxies – IV. The interrelation between dark and luminous matter

2019 ◽  
Vol 490 (4) ◽  
pp. 5451-5477 ◽  
Author(s):  
Chiara Di Paolo ◽  
Paolo Salucci ◽  
Adnan Erkurt
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Rotation Curve ◽  
High Surface ◽  
Dark Matter Halo ◽  
Rotation Curves ◽  
Central Surface ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies ◽  
Lsb Galaxies

ABSTRACT We investigate the properties of the baryonic and the dark matter components in low surface brightness (LSB) disc galaxies, with central surface brightness in the B band $\mu _0 \ge 23 \, \mathrm{mag \, arcsec}^{-2}$. The sample is composed of 72 objects, whose rotation curves show an orderly trend reflecting the idea of a universal rotation curve (URC) similar to that found in the local high surface brightness (HSB) spirals in previous works. This curve relies on the mass modelling of the co-added rotation curves, involving the contribution from an exponential stellar disc and a Burkert cored dark matter halo. We find that the dark matter is dominant especially within the smallest and less luminous LSB galaxies. Dark matter haloes have a central surface density $\Sigma _0 \sim 100 \, \mathrm{M}_{\odot } \, \mathrm{pc}^{-2}$, similar to galaxies of different Hubble types and luminosities. We find various scaling relations among the LSBs structural properties which turn out to be similar but not identical to what has been found in HSB spirals. In addition, the investigation of these objects calls for the introduction of a new luminous parameter, the stellar compactness C* (analogously to a recent work by Karukes & Salucci), alongside the optical radius and the optical velocity in order to reproduce the URC. Furthermore, a mysterious entanglement between the properties of the luminous and the dark matter emerges.

scholarly journals The Central Dynamics of Blue Low Surface Brightness Galaxies

2004 ◽  
Vol 220 ◽  
pp. 335-336
Author(s):  
Erik Zackrisson ◽  
Nils Bergvall
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Central Density ◽  
Disk Galaxies ◽  
Rotation Curves ◽  
Central Surface ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

We use optical, long-slit rotation curves to derive the slope of the central density profile in three blue disk galaxies with very faint central surface brightness values. We find the result to be in conflict with current cold dark matter predictions and to lend further support for pseudo-isothermal spheres as superior models for the dark halos of galaxies.

scholarly journals Fundamental Properties of the Dark and the Luminous Matter from the Low Surface Brightness Discs

Universe ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 344
Author(s):  
Paolo Salucci ◽  
Chiara di Paolo
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Stellar Disk ◽  
Rotating Disc ◽  
Fundamental Properties ◽  
Low Surface Brightness ◽  
Luminous Matter ◽  
Lsb Galaxies ◽  
The Universe ◽  
Disc Galaxies

Dark matter (DM) is one of the biggest mystery in the Universe. In this review, we start reporting the evidences for this elusive component and discussing about the proposed particle candidates and scenarios for such phenomenon. Then, we focus on recent results obtained for rotating disc galaxies, in particular for low surface brightness (LSB) galaxies. The main observational properties related to the baryonic matter in LSBs, investigated over the last decades, are briefly recalled. Next, these galaxies are analyzed by means of the mass modelling of their rotation curves both individual and stacked. The latter analysis, via the universal rotation curve (URC) method, results really powerful in giving a global or universal description of the properties of these objects. We report the presence in LSBs of scaling relations among their structural properties that result comparable with those found in galaxies of different morphologies. All this confirms, in disc systems, the existence of a strong entanglement between the luminous matter (LM) and the dark matter (DM). Moreover, we report how in LSBs the tight relationship between their radial gravitational accelerations g and their baryonic components gb results to depend also on the stellar disk length scale and the radius at which the two accelerations have been measured. LSB galaxies strongly challenge the ΛCDM scenario with the relative collisionless dark particle and, alongside with the non-detection of the latter, contribute to guide us towards a new scenario for the DM phenomenon.

scholarly journals A search for LSB dwarf galaxies in various environments

2004 ◽  
Vol 220 ◽  
pp. 341-342
Author(s):  
Sarah Roberts ◽  
Jonathan Davies ◽  
Sabina Sabatini
Keyword(s):  
Dark Matter ◽  
Hierarchical Clustering ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Low Surface Brightness ◽  
Galaxy Populations

The varying dwarf galaxy populations in different environments pose a problem for Cold Dark Matter (CDM) hierarchical clustering models. in this paper we present results from a survey conducted in different environments to search for low surface brightness (LSB) dwarf galaxies.

scholarly journals Observational Constraints on the Physical Parameters of Dark Matter Halos

2004 ◽  
Vol 220 ◽  
pp. 447-454
Author(s):  
Claude Carignan
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Physical Parameters ◽  
Observational Constraints ◽  
Dark Matter Halos ◽  
Low Surface Brightness ◽  
Interacting Systems ◽  
The Difference ◽  
Tidal Tails ◽  
Lsb Galaxies

After looking at the difference in the mass distribution between massive spiral and dwarf irregular (dIrr) and low surface brightness (LSB) galaxies, the central Dark Matter (DM) concentration (flat vs cuspy) in dwarf and LSB galaxies, derived from observations, will be examined. We will then present what kind of observational constraints can be put on the total mass and total extent of DM halos from the studies of individual galaxies, small groups, satellites' dynamics and tidal tails of interacting systems. Finally, we will discuss how limits on the physical parameters of DM halos could be set by deriving extended rotation curves beyond the HI radius (r > rHI), using either Lyα absorption or Hα emission observations.

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