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Globular clusters (GCs) are astronomical tapestries embroidered with an abundance of exotic stellar-type objects. Their high age promises a rich harvest of evolved stellar products, while the deep potential wells and high mass densities at their centres probably facilitate the formation of multiple-member stellar systems via increased stellar encounter rates. The ubiquity of low-mass X-ray binaries, thought to be the progenitors of millisecond pulsars (MSPs), explain the large number of observed GC radio pulsars and X-ray counterparts. The Fermi Large Area Telescope (LAT) recently unveiled the first gamma-ray GC pulsar (PSR J1823-3021A). The first observations of GCs in the GeV and TeV bands furthermore created much excitement, and in view of the above, it seems natural to explain these high-energy lanterns by investigating an MSP origin. An MSP population is expected to radiate several pulsed spectral components in the radio through gamma-ray wavebands, in addition to being sources of relativistic particles. The latter may interact with background photons in the clusters producing TeV excesses, while they may also radiate synchrotron photons as they traverse the cluster magnetic field. We present multiwavelength modelling results for Terzan 5. We also briefly discuss some alternative interpretations for the observed GC gamma-ray signals.
Dark matter (DM) is the most abundant material in the Universe, but has so far been detected only via its gravitational effects. Several theories suggest that pairs of DM particles can annihilate into a flash of light at gamma-ray wavelengths. While
Globular clusters are highly efficient radio pulsar factories. These pulsars can be used as precision probes of the clusters structure, gas content, magnetic field, and formation history; some of them are also highly interesting in their own right be
A cosmological zoom-in simulation which develops into a Milky Way-like halo is started at redshift 7. The initial dark matter distribution is seeded with dense star clusters, median mass $5times 10^5 M_sun$, placed in the largest sub-halos present, w
The optical and UV variability of the majority of AGN may be related to the reprocessing of rapidly-changing X-ray emission from a more compact region near the central black hole. Such a reprocessing model would be characterised by lags between X-ray
The proper motions of stars in the outskirts of globular clusters are used to estimate cluster velocity dispersion profiles as far as possible within their tidal radii. We use individual color-magnitude diagrams to select high probability cluster sta