0000000000234373
AUTHOR
J. Peñalver
First M87 Event Horizon Telescope Results. II. Array and Instrumentation
The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of th…
First M87 Event Horizon Telescope Results. I. the Shadow of the Supermassive Black Hole
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 ± 3 μas, which is circular and encompasses a central depression in brightness with a flux rati…
Exploring diversity among Spanish strains of Erwinia amylovora and possible infection sources
Aims: We have examined the intraspecific diversity of a collection of 63 Spanish strains of Erwinia amylovora, isolated from 1995 to 2001, to determine whether or not they could be grouped based on phenotypic or genotypic criteria and to investigate the sources of inoculum for fire blight dissemination in Spain. Methods and Results: Several biochemical and molecular techniques, such as miniaturized API 20E, API 50CH, ATB G-5 and API-ZYM tests, BIOLOG metabolic fingerprinting, PCR ribotyping, pulsed-field gel electrophoresis (PFGE), minisatellite-primed PCR (MSP-PCR), random amplified polymorphic DNA (RAPD) analyses and AFLP were used. We report the first identification in Spain of the PFG…