tailieunhanh - Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole

An important part of text understanding arises from understanding the semantics of events described in the narrative, such as identifying the events that are mentioned and how they are related semantically. For instance, when given a sentence “The police arrested him because he killed someone.”, humans understand that there are two events, triggered by the words “arrested” and “killed”, and that there is a causality relationship between these two events. Besides being an important component of discourse understanding, automatically identifying causal re- lations between events is important for various nat- ural language processing (NLP) applications such as question answering, etc. In this work, we auto- matically detect and extract causal relations between events in text | Imaging an Event Horizon submm-VLBI of a Super Massive Black Hole A Science White Paper to the Decadal Review Committee Authors Sheperd Doeleman MIT Haystack Observatory Eric Agol U. Washington Don Backer UC Berkeley Fred Baganoff MIT Geoffrey C. Bower UC Berkeley Avery Broderick CITA Andrew Fabian U. Cambridge Vincent Fish MIT Haystack Observatory Charles Gammie U. Illinois Urbana-Champaign Paul Ho ASIAA Mareki Honma NAOJ Thomas Krichbaum MPIfR Avi Loeb Harvard-Smithsonian CfA Dan Marrone NRAO U. Chicago Mark Reid Harvard-Smithsonian CfA Alan Rogers MIT Haystack Observatory Irwin Shapiro Harvard-Smithsonian CfA Peter Strittmatter U. Arizona Steward Observatory Remo Tilanus JCMT Jonathan Weintroub Harvard-Smithsonian CfA Alan Whitney MIT Haystack Observatory Melvyn Wright UC Berkeley Lucy Ziurys U. Arizona Steward Observatory Science Frontier Panels Galaxies across Cosmic Time Cosmology and Fundamental Physics A Unique Scientific Opportunity As the most extreme self-gravitating objects predicted by Einstein s General Theory of Relativity GR black holes lie squarely at the intersection of Astronomy and Physics. They are now believed to reside at the heart of most galaxies in many X-ray binary systems and may power gamma-ray bursts black holes are central to questions of stellar evolution galaxy formation and mergers astrophysical jets and the nature of space-time. A long-standing goal in astrophysics is to observe and image the immediate environment of a black hole with resolution comparable to the event horizon. Such observations would open a new window on the study of General Relativity in the strong-field regime astrophysics of accretion and outflow at the edge of a black hole and fundamental black hole physics . spin . The capabilities of Very Long Baseline Interferometry VLBI have improved steadily at short wavelengths making it almost certain that direct imaging of black holes can be achieved within the next decade. The most compelling evidence for this is