Core-Cusp revisited and Dark Matter Phase Transition Constrained at O(0.1) eV with LSB Rotation Curve

Abstract

Recently a new particle physics model called Bound Dark Matter (BDM) has been proposed in which dark matter (DM) particles are massless above a threshold energy (Ec) and acquire mass below it due to nonperturbative methods. Therefore, the BDM model describes DM particles which are relativistic, hot dark matter, in the inner regions of galaxies and describes nonrelativistic, cold dark matter, where halo density is below rho_c = Ec^4. To realize this idea in galaxies we use a particular DM cored profile that contains three parameters: a scale length (rs) and density (rho_0) of the halo, and a core radius (rc) stemming from the relativistic nature of the BDM model. We test this model by fitting rotation curves of seventeen Low Surface Brightness galaxies from The HI Nearby Galaxy Survey (THINGS). Since the energy Ec parameterizes the phase transition due to the underlying particle physics model, it is independent on the details of galaxy or structure formation and therefore the DM profile parameters rs, rc, Ec are constrained, leaving only two free parameters. The high spatial and velocity resolution of this sample allows to derive the model parameters through the numerical implementation of the chi^2-goodness-of-fit test to the mass models. We compare the fittings with those of Navarro-Frenk-White (NFW), Burkert, and Pseudo-Isothermal (ISO) profiles. Through the results we conclude that the BDM profile fits better, or equally well, than NFW, Burkert, and ISO profiles and agree with previous results implying that cored profiles are preferred over the N-body motivated cuspy profile. We also compute 2D likelihoods of the BDM parameters rc and Ec for the different galaxies and matter contents, and find an average galaxy core radius rc=300 pc and a transition energy Ec = 0.11 eV when the DM halo is the only component. In Kroupa mass model, we obtain a core rc=1.48 kpc, and energy Ec=0.06 eV.

54 pages, 26 Figures. Submitted to Phys. Rev. D. Refer also to Phys.Rev.D84:121301,2011

References in corpus (10)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• The Core-Cusp Problem
• Equation of state and QCD transition at finite temperature
• A constant dark matter halo surface density in galaxies
• The Atacama Cosmology Telescope: Cosmological Parameters from the 2008 Power Spectra
• The Universal Rotation Curve of Spiral Galaxies. II The Dark Matter Distribution out to the Virial Radius
• BDM Dark Matter: CDM with a core profile and a free streaming scale
• Galactic phase transition at Ec=0.11 eV from rotation curves of cored LSB galaxies and nonperturbative dark matter mass

Cited by in corpus (7)

• Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves
• Testing Grumiller's modified gravity at galactic scales
• Extra relativistic degrees of freedom without extra particles using Planck data
• Bound Dark Matter (BDM) towards solving the Small Scale Structure Problem
• The virial mode $k_v$ approach to Structure Formation with Warm Dark Matter
• Spectral distortions in the decaying QCD dark matter scenario
• Dark Matter Phase Transition Constrained at O(0.1) eV with LSB Rotation Curves