The distant Universe and something about gravitational waves

The distant Universe – on a side of A4 CMB formation CMB power spectrum provides: Flatness Baryon density Cool regions overdense Structures measured by: Acoustic Oscillations Sachs-Wolfe effect Universe neutral – dark ages Halo formation: Overdensities behave as closed universes. Perturbations collapse in 3-D to make sheets, then filaments then galaxies. Haloes are 200 times the critical density at that epoch. First light - Reionization Optical depth to reionization probed through: CMB polarization/temperature Gunn-Peterson trough 21cm emission Lyman-break galaxies (numerous but faint) Gamma-ray bursts (very luminous, rare, and transient) Quasars Rare beyond z~6. Hard to explain BH masses) Light absorbed in Ly-alpha forest. Lyman limits at 912A, but Lyman break at Ly-alpha (1216A) at high-z. Haloes merge and grow. Grow BHs, change LF shape First star formation: H2 cooling High temperature gives high Jeans mass May make very massive stars Luminosity functions: Jeans Mass: Evolving LF provides SFR (in UV), masses (in IR) andionizing photon budget Local SFR has T~10-20 K, low metalicity SFR ~ K

Gravitational waves from non-spherically symmetric accelerating masses R= distance from source, r = separation of masses

Strain for solar system at 1 ly ~ Abbott et al. 2016

Merging compact object binaries

Abbott et al. 2016