2 research outputs found
Black Coral Assemblages from Machalilla National Park (Ecuador)
Little is known about density and structure of black coral populations
of the continental Pacific coasts of Central and South America. Species diversity
and ecology of the antipatharian fauna of Machalilla National Park (Province of
Manab\ued, Ecuador) were surveyed using scuba, and two species, Myriopathes panamensis
and Antipathes galapagensis, were identified. New information on the two
species and their associated fauna was obtained through both underwater observations
and laboratory analyses. Specific associations with stalked barnacles and
parasitic zoanthids are described. An underwater visual census indicated that the
black coral assemblage had a maximal density between depths of 15 and 30 m.
Myriopathes panamensis commonly occurred below 20 m depth, and A. g alapagensis
was mainly recorded from deeper than 25 m depth. Surveyed sites were characterized
by sparse rocks mixed with sandy patches, and occurrence of black corals
was mainly related to availability of rocky substrate. With an average density of
0.5 colonies m 122, the shallow black coral community of Machalilla National Park
is one of the densest in the world. Data from this study represent a clear baseline
for monitoring of population dynamics of benthic organisms in an area subjected
to periodic El Ni\uf1o and La Ni\uf1a events, which may greatly affect composition
and abundance of the marine communities
Multi-epoch monitoring of TXS 0506+056 with MAGIC and MWL partners
The measurement of an astrophysical flux of high-energy neutrinos by IceCube is an important step towards finding the long-sought sources of cosmic rays. Nevertheless, the long exposure neutrino sky map shows no significant indication of point sources so far. The real-time follow- up of neutrino events turned out to be the most successful approach in neutrino point-source searches. It brought, among others, the most compelling evidence for a neutrino point source: the flaring gamma-ray blazar TXS 0506+056 in coincidence with a single high-energy neutrino from IceCube (IceCube-170922A). The fast multiwavelength(MWL) follow-up of this alert was key for establishing this coincidence and constraining the subsequent theoretical modeling for this event. In the long run, accurate and contemporaneous MWL spectral measurements are essential ingredients in investigating the physical processes leading to particle acceleration and emission of radiation. A deeper understanding of those processes allows us to put constraints on the potential neutrino emission. Here we present the light curves and simultaneous spectral energy distributions from November 2017 till February 2021 of MAGIC and MWL monitoring of TXS 0506+056. The more than two-year-long rise and high state of the radio light curve of TXS 0506+056, which started near the time of the IceCube neutrino detection, seems to have ended, as indicated by a steep decrease in the first half of 2021. We also present the theoretical interpretation of our observations