Day 739

Monday.

1301.5067
Direct gravitational imaging of intermediate mass black holes in extragalactic haloes
Inoue, Rashkov, Silk, Madau

Propose to directly detect IMBHs by observing multiply imaged QSO-galaxy or gg LS systems in the submillimter bands with high angular resolution.  The silhouette of an IMBH in the lensing galaxy halo would appear as either a monopole-like or a dipole-like variation at the scale of the Einstein radius against the Einstein ring of the dust-emitting region surrounding the QSO.  Use a particle tagging technique to dynamically populate a MW-sized DM halo with BHs and show that the surface mass density and number density of IMBHs have power-law dependences on the distance from the center of the host halo if smoothed on a scale of ~1kpc.  Most of the BHs orbiting close to the center are freely roaming as they have lost their DM hosts during infall due to tidal stripping.  Next generation submillimter telescopes with high angular resolution (<0.3 max) will be capable of directly mapping such off-nuclear freely roaming IMBHs with a mass of ~1e6 Msun in a lending galaxy that harbors a O(1e9 Msun) mass SMBH in its nucleus.

1409.1578
The orthogonally aligned dark halo of an Edge-on lensing galaxy in the Hubble Frontier Fields: a challenge for modified gravity
Diego, Broadhurst, Benitez, Lim, Lam

8" cluster lensed image (tangential shear), symmetrically bend in the middle by an edge-on lenticular galaxy (secondary deflection).  An opportunity to place relative strong constraints on the lensing effect of this galaxy.  Model the stelar lensing contribution using the observed pixels belonging to the galaxy, in 2D, and add to this a standard parameterized dark halo component.  Find combined total mass of 3e11 Msun, irrespective of the choice of parameters.  ...  Alternative theories of gravity where the radial dependence is modified to avoid the need for DM are challenged by this finding, since generically these must be tied to the baryonic component which here is a stellar disk oriented nearly orthogonally to the lensed image deflection.

1409.1640
The effect of macro model uncertainties on microlensing modelling of lensed quasars
Vernardos, Fluke

Microlensed quasars studied for structure of multiply imaged quasars, especially the accretion disc and central SMBH system.  But the derived constraints on models are affected by large systematic errors in the macro models, the microlensing magnification maps, and the convolution with realistic disc profiles.  Different macro models of galaxy lens can lead to different values of kappa and gamma.  Strategies of mitigating the effect of Delta kappa, Delta gamma are discussed in order to understand and control this potential source of systematic errors in accretion disc constraints derived from microlensing.