Constraints on the mass-concentration relation of cold dark matter halos with 11 strong gravitational lenses. (arXiv:1909.02573v1 [astro-ph.CO])

Constraints on the mass-concentration relation of cold dark matter halos with 11 strong gravitational lenses. (arXiv:1909.02573v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Gilman_D/0/1/0/all/0/1">Daniel Gilman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Du_X/0/1/0/all/0/1">Xiaolong Du</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benson_A/0/1/0/all/0/1">Andrew Benson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Birrer_S/0/1/0/all/0/1">Simon Birrer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nierenberg_A/0/1/0/all/0/1">Anna Nierenberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Treu_T/0/1/0/all/0/1">Tommaso Treu</a>

The mass-concentration relation of dark matter halos reflects the assembly
history of objects in hierarchical structure formation scenarios, and depends
on fundamental quantities in cosmology such as the primordial slope of the
matter power-spectrum. This relation is unconstrained by observations on
sub-galactic scales. We derive the first measurement of the mass-concentration
relation using the image positions and flux ratios from eleven quadruple-image
strong gravitational lenses (quads) in the mass range $10^{6} – 10^{10}
M_{odot}$, assuming cold dark matter. Our analysis framework includes both
subhalos and line of sight halos, marginalizes over nuisance parameters
describing the lens macromodel, accounts for finite source effects on lensing
observables, and simultaneously constrains the normalization and logarithmic
slope of the mass-concentration relation, and the normalization of the subhalo
mass function. At $z=0$, we constrain the concentration of $10^{8} M_{odot}$
halos $c=12_{-5}^{+6}$ at $68 %$ CI, and $c=12_{-9}^{+15}$ at $95 %$ CI. For
a $10^{7} M_{odot}$ halo, we obtain $68 %$ ($95 %$) constraints
$c=15_{-8}^{+9}$ ($c=15_{-11}^{+18}$), while for $10^{9} M_{odot}$ halos
$c=10_{-4}^{+7}$ ($c=10_{-7}^{+14}$). These results are consistent with the
theoretical predictions from mass-concentration relations in the literature,
and establish strong lensing by galaxies as a powerful probe of halo
concentrations on sub-galactic scales across cosmological distance.

The mass-concentration relation of dark matter halos reflects the assembly
history of objects in hierarchical structure formation scenarios, and depends
on fundamental quantities in cosmology such as the primordial slope of the
matter power-spectrum. This relation is unconstrained by observations on
sub-galactic scales. We derive the first measurement of the mass-concentration
relation using the image positions and flux ratios from eleven quadruple-image
strong gravitational lenses (quads) in the mass range $10^{6} – 10^{10}
M_{odot}$, assuming cold dark matter. Our analysis framework includes both
subhalos and line of sight halos, marginalizes over nuisance parameters
describing the lens macromodel, accounts for finite source effects on lensing
observables, and simultaneously constrains the normalization and logarithmic
slope of the mass-concentration relation, and the normalization of the subhalo
mass function. At $z=0$, we constrain the concentration of $10^{8} M_{odot}$
halos $c=12_{-5}^{+6}$ at $68 %$ CI, and $c=12_{-9}^{+15}$ at $95 %$ CI. For
a $10^{7} M_{odot}$ halo, we obtain $68 %$ ($95 %$) constraints
$c=15_{-8}^{+9}$ ($c=15_{-11}^{+18}$), while for $10^{9} M_{odot}$ halos
$c=10_{-4}^{+7}$ ($c=10_{-7}^{+14}$). These results are consistent with the
theoretical predictions from mass-concentration relations in the literature,
and establish strong lensing by galaxies as a powerful probe of halo
concentrations on sub-galactic scales across cosmological distance.

http://arxiv.org/icons/sfx.gif