Journal Club


"The CHEOPS mission"

Alexis Smith (Institute of Planetary Research, DLR)

CHEOPS - CHaracterising ExOPlanet Satellite - is ESA's first small mission, and is due to launch in the first half of 2019. CHEOPS will perform ultra-high precision photometry on bright stars already known to host planets. The mission has numerous science goals, but a major aim is to measure the bulk density of super-Earths and Neptunes orbiting bright stars and provide suitable targets for future in-depth characterisation studies of exoplanets in these mass and size ranges. A significant fraction (20 %) of observing time is open for guest observers, with the first announcement of opportunity expected soon.


"Modelling of the potential Dark matter decay signal from the Local Group sources"

Wojciech A. Hellwing (Centrum Fizyki Teoretycznej (PAN))

Dark matter particles may decay emitting photons. If the dark matter particle mass is in the keV range, a decay line in the X-ray part of the spectrum could be produced. Drawing on the family of hydrodynamic simulations of galaxy formation of the EAGLE project, we provide predictions for the expected line fluxes from galaxies of different masses, from dwarfs to bright galaxies, including Local Group analogues, and from galaxy clusters at various redshifts including Perseus analogues. We provide specific predictions for observations with XMM-Newton and with the planned X-ray telescopes XRISM and ATHENA, both for cold and warm dark matter models. We consider trends with stellar and halo mass and evaluate the scatter in the expected fluxes arising from the anisotropic halo mass distribution and from object-to-object variations. We show that the median X-ray decay flux of a galaxy measured with XMM-Newton and ATHENA is ∝ d −1.35 (M/M S ) 0.3 (1+M/M S ) 0.7 for d = [10, 40] Mpc and M S = 2×10 10 M . We also predict the expected width of the line which, for the Perseus cluster, for example, is expected to lie in the range 1300-1500 km/s


"Dynamics and formation of obscuring tori in AGNs"

Swayamtrupta Panda (CAMK, Warsaw)

Based on Bannikova et al. 2018: