Publications

  • Very High Energy γ-Rays from the Universe's Middle Age: Detection of the z = 0.940 Blazar PKS 1441+25 with MAGIC

    The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with a significance of 25.5σ using the MAGIC telescopes. Together with the gravitationally lensed blazar QSO B0218+357 (z = 0.944), PKS 1441+25 is the most distant very high energy (VHE) blazar detected to date. The observations were triggered

    Ahnen, M. L. et al.

    Advertised on:

    12
    2015
  • Very-High-Energy γ-Ray Observations of a Strong Flaring Activity in M 87 in 2008 February

    M 87 is the only known non blazar radio galaxy to emit very high energy (VHE) gamma-rays. During a monitoring program of M 87, a rapid flare in VHE gamma-rays was detected by the MAGIC telescope in early 2008. The flux was found to be variable above 350 GeV on atimescaleas short as 1 day at a significance level of 5.6σ. The highest measured flux

    Mazin, D. et al.

    Advertised on:

    12
    2008
  • Vestige of a Beginning: a Quest for 142Nd Anomalies in the Earth

    Although seismic tomography evidence leaves no room for fully layered mantle convection, it is still arguable that over Earth's history convection has efficiently homogenized mantle composition. We first searched for remains of the early differentiation of the planet in the 3.8 Ga rocks from Isua, Greenland. A sensitive indicator is the extinct

    Boyet, M. et al.

    Advertised on:

    12
    2002
  • VGCF detection of galaxy systems at intermediate redshifts

    We continue the development of our Voronoi Galaxy Cluster Finder (VGCF) technique by applying it to galaxy catalogs obtained with B and R band observations of four high galactic latitude fields of 0.5 × 0.5 square degrees each. These fields are deep (Rlim ˜ 23, Blim ˜ 26) and partially overlap the Palomar Distant Cluster {Survey} (PDCS) fields at

    Barrena, R. et al.

    Advertised on:

    12
    2005
  • VICS: Intergalactic Globular Clusters in Virgo

    Deep HST ACS images of Virgo from the VICS project (Ciardullo et al.) contain 4 resolved objects that appear to be intergalactic globular clusters (IGCs). Evidence for this interpretation comes from the objects' integrated colors and magnitudes, which are consistent with those of Virgo globulars, their radial surface brightness profiles, which are

    Williams, B. F. et al.

    Advertised on:

    12
    2005
  • VICS: Stellar Populations of a Dwarf Spheroidal Galaxy in the Virgo Cluster

    We report the discovery of a very low-luminosity (MV -10) dwarf galaxy in the Virgo Cluster within the ACS field of the VICS Project (Ciardullo et al.). The galaxy, which is ˜ 1 kpc in extent, is clearly resolved into stars, and provides us with the first direct look at the stellar population of a low-luminosity system in a galaxy cluster. A F606W

    Durrell, P. R. et al.

    Advertised on:

    12
    2005