The origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. I will discuss that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei.

Context. The international whole earth blazar telescope (WEBT) consortium planned and carried out three days of intensive micro-variability observations of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was chosen due to its bright apparent magnitude range, its high declination, and its very large duty cycle for micro-variations.
Aims. We report here on the long continuous optical micro-variability light curve of 0716+714 obtained during the multi-site observing campaign during which the Blazar showed almost constant variability over a 0.5 magnitude range. The resulting light curve is presented here for the first time. Observations from participating observatories were corrected for instrumental differences and combined to construct the overall smoothed light curve.
Methods. Thirty-six observatories in sixteen countries participated in this continuous monitoring program and twenty of them submitted data for compilation into a continuous light curve. The light curve was analyzed using several techniques including Fourier transform, Wavelet and noise analysis techniques. Those results led us to model the light curve by attributing the variations to a series of synchrotron pulses.
Results. We have interpreted the observed microvariations in this extended light curve in terms of a new model consisting of individual stochastic pulses due to cells in a turbulent jet which are energized by a passing shock and cool by means of synchrotron emission. We obtained an excellent fit to the 72-hour light curve with the synchrotron pulse model.

Since more than two years, the First G-APD Cherenkov Telescope (FACT) has been operational at the Observatorio del Roque de los Muchachos at the Canary Island of La Palma. Using the Imaging Atmospheric Cherenkov Technique, it is observing in the gamma-ray regime at TeV energies. The two major goals of the project are monitoring of active galactic nuclei at TeV energies and the proof of principle for silicon based photo sensors (Geigermode Avalanche Photodiodes: G-APDs) in Cherenkov astronomy.

Results demonstrating the performance and stability of G-APDs will be presented explaining how these devices facilitate observations in Cherenkov astronomy. Especially the robustness towards strong ambient light makes them ideal for long-term monitoring, as observations during strong moon light are possible enlarging the duty cycle of the instrument.

Active galactic nuclei are known to be extremely variable objects at all energies. However, the origin of these flux variations cannot be explained well by current theoretical models. Long-term monitoring and simultaneous observations in all energy ranges are the key to better understand the processes causing the variability and to investigate the correlation between different energy ranges.

Few active galactic nuclei have been monitored in the last two years with FACT. Several outbursts could be detected from Markarian 421 and Markarian 501. First results from these two years observations will be presented.

Early-type galaxies form a tight sequence within in the colour-magnitude space which is known as the red-sequence. This red-sequence has been used to search for galaxy clusters and study the properties of quiescent galaxies up to z~1. However, the formation and build-up of the red-sequence is still uncertain and a matter of debate. I will present new observational constraints based on our analysis of the luminosity function and colour-magnitude relation using a sample of 50,000 galaxies from the ongoing VIMOS Public Extragalactic Redshift Survey (VIPERS) project. Our data are a combination of multi-wavelength photometry with precise spectroscopic redshifts, complemented by spectroscopic properties derived from stacked spectra. I will show how these data allow us to constrain both the evolution of the luminosity function and the galaxy colours, the star formation history of early-type galaxies, and discuss possible physical mechanisms that are important for the origin and the build-up of the red-sequence.

I will present an evolutionary model for the origin of Andromeda II, a dSph satellite of M31, involving a merger between two disky dwarf galaxies than explains the origin of prolate rotation recently detected in the kinematic data for And II. The simulation traces the evolution of two dwarfs, whose structural parameters differ only in their disk scale lengths, placed on a radial orbit towards each other with their angular momenta inclined by 90 deg. After 5 Gyr the merger remnant forms a stable triaxial galaxy with rotation only around the longest axis. This prolate rotation is naturally explained as due to the symmetry of the initial configuration which leads to the conservation of angular momentum components along the direction of the merger. The stars originating from the two dwarfs show significantly different surface density profiles while having very similar kinematics in agreement with the properties of separate stellar populations in And II. I will also discuss an alternative scenario for the formation of And II, via tidal stirring of a disky dwarf galaxy. While intrinsic rotation occurs naturally in this model as a remnant of the initial rotation of the disk, it is mostly around the shortest axis of the stellar component. The rotation around the longest axis is induced only occasionally and remains much smaller that the system's velocity dispersion. I conclude that although tidal origin of the velocity distribution in And II cannot be excluded, it is much more naturally explained within the scenario involving a past merger event. Thus, in principle, the presence of prolate rotation in dSph galaxies of the Local Group and beyond may be used as an indicator of major mergers in their history or even as a way to distinguish between the two scenarios of their formation.

We present an update of the LXTX correlation with a larger data sample of 101 GRBs with well sampled lightcurves. Since some of this correlation could result from the redshift dependences of these intrinsic parameters, namely their cosmological evolution we use the Efron-Petrosian method to reveal the intrinsic nature of this correlation. We find that a substantial part of the correlation is intrinsic and describe how we recover it and how this can be used to constrain physical models of the plateau emission, whose origin is still unknown.

We extended the analysis of the LXTX correlation to correlations between the afterglow and the prompt emission. We find a tight physical scaling between the afterglow luminosity Lx and the prompt emission mean luminosities. The highest correlated subsample in the afterglow leads also to the highest prompt–afterglow correlations. Such events can be considered standard GRBs for astrophysics and cosmology.

Regarding the cosmological problem, we show how changes of the observed slope, bobs, of the LXTX correlation in GRB afterglows affect the determination of the cosmological parameters. With 101 GRBs simulated with a central value of bobs that differs on the intrinsic one by a 5σ factor, we find an overestimated value of the matter density parameter, Ω_M compared to the value obtained with SNe Ia, while the Hubble constant, H₀, best fit value is still compatible in 1 σ. Instead, for a subsample of high luminous GRBs (HighL), H₀ and Ω_M are not more compatible in 1σ and Ω_M is underestimated by the 13%. However, the HighL sample choice reduces dramatically the intrinsic scatter of the correlation, thus possibly identifying this sample as the standard canonical `GRBs'. We conclude that any approach that involves cosmology should take into consideration only intrinsic correlations not the observed ones.

Comet C/2012 S1 (ISON) was discovered on 21 September 2012 and subsequently identified as a recent escapee from the Oort cloud, having been stored in deep freeze since the formation of the solar system. ISON quickly attracted immense attention owing to the extremely good visibility prospects. On 29 November 2013 the comet was going to pass the Sun at a sensational distance of less than one solar diameter from the photosphere, grazing the solar corona and promising an unforgettable sight a couple weeks later. As it happens with comets, however, ISON chose its own way, and after passing perihelion was never seen again in the night sky. Instead, scientists and the public witnessed the apparent dissipation of the comet's nucleus at the day of perihelion, closely following ISON in a live broadcast from solar space telescopes. I will discuss the "anatomy" of ISON's demise, including insightful data from millimeter spectroscopy, and show how it fits to the emerging broader view of the decay of comets.