Astrid Lamberts

When and where did GW150914 form

The recent LIGO detection of gravitational waves (GW150914), likely originating from the merger of two ∼ 30M_⊙ black holes suggests progenitor stars of low metallicity ([Z/Z_⊙] ≲ 0.3), constraining when and where the progenitor of GW150914 may have formed. We combine estimates of galaxy properties (star-forming gas metallicity, star formation rate and merger rate) across cosmic time to predict the low redshift black hole – black hole merger rate as a function of present day host galaxy mass, M_(gal), the formation redshift of the progenitor system z_f and different progenitor metallicities Z_p. For Z_p ⩾ 0.1Z_⊙, the signal is dominated by binaries in massive galaxies with z_f ≃ 2 while below Z_p ⩽ 0.1Z_⊙ most mergers come from binaries formed around z_f ≃ 0.5 in dwarf galaxies. Additional gravitational wave detections from merging massive black holes will provide constraints on the mass–metallicity relation and massive star formation at high redshifts.

Modelling the high-energy emission from gamma-ray binaries using numerical relativistic hydrodynamics

Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to

PATCHY BLAZAR HEATING: DIVERSIFYING THE THERMAL HISTORY OF THE INTERGALACTIC MEDIUM

i\approx 35^{\rm o}

Predicting the binary black hole population of the Milky Way with cosmological simulations

. There is a tension between the hard VHE spectrum and the level of X-ray to MeV emission, which requires differing magnetic field intensities that are hard to achieve with a constant magnetisation

Importance of Resolving the Spectral Support of Beam-plasma Instabilities in Simulations

\sigma

The Linear Instability of Dilute Ultrarelativistic e± Pair Beams

and Lorentz factor

From the top down and back up again: star cluster structure from hierarchical star formation

\Gamma_{p}

Modelling Jets, Tori and Flares in Pulsar Wind Nebulae

of the pulsar wind. Our best compromise implies

BOW TIES IN THE SKY. I. THE ANGULAR STRUCTURE OF INVERSE COMPTON GAMMA-RAY HALOS IN THE FERMI SKY

\sigma\approx 1

Relativistic simulations of long-lived reverse shocks in stratified ejecta: the origin of flares in GRB afterglows

and