Multiwavelength observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies occurred, provide a detailed picture of the evolution of its emission. The complete data set from this campaign is presented, including observations in VHE gamma-rays (H.E.S.S.), X-rays (RXTE, CHANDRA, SWIFT XRT), optical (SWIFT UVOT, Bronberg, Watcher, ROTSE), and in the radio band (NRT, HartRAO, ATCA). Optical and radio light curves from 2004 to 2008 are compared to the available VHE data from this period, to put the 2006 campaign into the context of the long-term evolution of the source. The paper is in press in A&A and can be found on the preprint server: arXiv:1201.4135 .

The blazar 1ES 0414+009 (at redshift z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE) gamma-rays due to its high X-ray and radio flux. In observations made between October 2005 and December 2009 with H.E.S.S., 1ES 0414+009 is detected for the first time in the VHE band. An excess of 224 events is measured, corresponding to a significance of 7.8 sigma. In the Fermi (GeV) energy range, the source exhibits a rather hard spectrum, which continues into the H.E.S.S. (TeV) range once corrected for absorption by the extragalactic background light. The paper is in press in A&A and can be found on the preprint server: arXiv:1201.2044 .

The paper covers a 2010 joint campaign on the giant radio galaxy M 87 by the H.E.S.S., MAGIC and VERITAS instruments, by Chandra and by VLBA, including a well-sampled flare at VHE energies. VLBA radio observations of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken ~3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core. The paper is in press in ApJ and can be found on the preprint server: arXiv:1111.5341 .

The assembly of the steel structure for the 600 m^2 H.E.S.S. II telescope was completed in mid-November, and the drives installed. Mirrors and camera will be installed in the first half of 2012. (Note that the H.E.S.S. II telescope is located in between the two H.E.S.S. I telescopes shown in the image, not in the foreground! Click on image for larger version.)

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A degree-scale extended VHE gamma ray source around the young massive stellar cluster Westerlund 1 is detected in 45 hours of HESS observations in the years 2004 to 2008. As potential sources, the stellar cluster Wd 1, the pulsar PSR J1648-4611, the magnetar CXOU J164710.2-455216 and the X-ray binary 4U 1642-45 are discussed. The paper is in press in A&A and can be found on the preprint server: arXiv:1111.2043 .

The BL Lac object PKS 2005-489 was the target of a multiwavelength campaign with simultaneous observations in the TeV gamma-ray (H.E.S.S.), GeV gamma-ray (Fermi), X-ray (RXTE, Swift), UV (Swift) and optical (ATOM, Swift) bands. The campaign was carried out during a high flux state in the synchrotron regime; the flux in the optical and X-ray bands reached the level of historical maxima. The paper is published in A&A 533 (2011) A110.

HESS J1356-645 is a new extended source of VHE gamma rays, with a size of about 0.2 degr. and a flux of about 11% of the Crab flux. Radio and X-ray data reveal faint non-thermal diffuse emission coincident with HESS J1356-645. HESS J1356-645 is most likely associated with the young and energetic pulsar PSR J1357-6429. The paper is in press in A&A and can be found on the preprint server: arXiv:1108.2855 .

An extended VHE gamma-ray source is located in the close vicinity of the Galactic globular cluster Terzan 5. The probability of a chance coincidence with Terzan 5 and an unrelated VHE source is quite low. With the largest population of identified millisecond pulsars (msPSRs), a very high core stellar density and the brightest GeV range flux as measured by Fermi-LAT, Terzan 5 stands out among Galactic globular clusters. Interpretation of the available data accommodates several possible origins for this VHE gamma-ray source, although none of them offers a satisfying explanation of its peculiar morphology. The paper is in press in A&A and can be found on the preprint server: arXiv:1106.4069 .

The discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further observations of this source. The deeper observation of the source - resulting in total in 59 h of data - has revealed a large shell-type structure with similar position and extension as the radio SNR, thus confirming their association and making HESS J1731-347 the fourth SNR with a shell morphology at TeV energies. The paper is in press in A&A and can be found on the preprint server: arXiv:1105.3206 .

Observations of the globular clusters NGC 6388 and M 15 were carried out by the H.E.S.S. array of Cherenkov telescopes for a live time of 27.2 and 15.2 hours, respectively. No hints of dark matter annihilation signals are detected. Based on models of the dark matter content of these clusters, limits on the dark matter self-annihilation cross section are derived. The paper is in press in ApJ and can be found on the preprint server: arXiv:1104.2548 .

Exploiting the large exposure towards the Galactic Center region, a search for very high energy gamma ray emission from self-annihilating dark matter is performed in a region of projected distance of about 45 to 150 pc from the Galactic Center, exclusing the region of the astrophysical gamma-ray source at the Galactic Center. The background-subtracted gamma-ray spectrum shows no hint of a residual gamma ray flux. The dark matter limits derived are among the best reported so far for the TeV energy range. The paper is in press in PRL and can be found on the preprint server: arXiv:1103.3266 .

The newly detected point-like source HESS J1943+213, located in the Galactic plane, coincides with the X-ray source IGR J19443+2117. Available multi-wavelength data favor an interpretation as an extreme, high-frequency peaked BL Lac object. This would be the first time a blazar is detected serendipitously from ground-based VHE observations, and the first VHE AGN detected in the Galactic Plane. The paper is in press in A&A and can be found on the preprint server: arXiv:1103.0763.

Pulsar PSR B1706-44 has a long history as suspected source of VHE gamma rays. H.E.S.S. observations now establish the region surrounding the pulsar, with the remnant G343.1-2.3, as a quite extended source of gamma rays. The centroid of the gamma ray source is, however, considerably offset from the pulsar, and no significant emission is detected at the location of the energetic pulsar itself. The paper is in press in A&A and can be found on the preprint server: arXiv:1102.0773.

Several models of Quantum Gravity predict Lorentz Symmetry breaking at energy scales approaching the Planck scale (10^19 GeV), manifesting itself in a dependence of the propagation speed on photon energy, and hence in dispersion of arrival times of photons from burst-like events. Improving upon an earlier publication, analysis of PKS 2155-304 flare gamma ray distributions in energy and time by means of a likelihood fit improves sensitivity by a factor 3, and provides a lower limit on the effective quantum gravity scale of 2.1x10^18 GeV, for linear variation of speed with energy. The paper is in press in Astroparticle Physics and can be found on the preprint server: arXiv:1101.3650.

Dwarf spheroidal galaxies such as Sculptor and Carina Dwarf are considered prime targets for signs of dark matter annihilation. Based on about 12 h and 15 h of data, respectively, upper limits on the TeV photon flux and on the dark matter annihilation cross section are reported, also discussing possible enhancements of the gamma ray flux due to the Sommerfeld effect or internal Bremssstrahlung. The paper is in press in Astroparticle Physics and can be found on the preprint server: arXiv:1012.5602.