نتایج جستجو برای: astronomical units
تعداد نتایج: 179278 فیلتر نتایج به سال:
Modern graphics processing units (GPUs) are inexpensive commodity hardware that offer Tflop/s theoretical computing capacity. GPUs are well suited to many compute-intensive tasks including digital signal processing. We describe the implementation and performance of a GPU-based digital correlator for radio astronomy. The correlator is implemented using the NVIDIA CUDA development environment. We...
Recently integral field spectroscopy has become a band-wagon among the optical astronomical community and most of the 8m class telescopes plan to offer this as part of their instrumentation package. The possibility of expanding integral field spectroscopy into the near infrared (1-2.5μm) opens exciting new possibilities for the study of a variety of astronomical objects. In this paper, we discu...
In this work we show that modifying the thermal history of the Universe by including an early period of matter domination can lead to the formation of astronomical objects. However, the survival of these objects can only be possible if the dominating matter decays to a daughter particle which is not only almost degenerate with the parent particle but also has an open annihilation channel. This ...
When astronomers analyze sky images, they need to identify the newly observed celestial objects in the catalog of known objects. We have developed a technique for indexing catalogs, which supports fast retrieval of closely matching catalog objects for every object in new images. It allows processing of a sky image in less than a second, and it scales to catalogs with billions of objects. Keywor...
Plutarch and Heraclitus believed a certain passage in the 20th book of the Odyssey ("Theoclymenus's prophecy") to be a poetic description of a total solar eclipse. In the late 1920s, Schoch and Neugebauer computed that the solar eclipse of 16 April 1178 B.C.E. was total over the Ionian Islands and was the only suitable eclipse in more than a century to agree with classical estimates of the deca...
Understanding dynamic conditions in the Solar Nebula is the key to prediction of the material to be found in comets. We suggest that a dynamic, large-scale circulation pattern brings processed dust and gas from the inner nebula back out into the region of cometesimal formation-extending possibly hundreds of astronomical units (AU) from the sun-and that the composition of comets is determined by...
We analyze PLANET collaboration data for MACHO 97-BLG-41, the only microlensing event observed to date in which the source transits two disjoint caustics. The PLANET data, consisting of 46 V-band and 325 I-band observations from five southern observatories, span a period from the initial alert until the end of the event. Our data are incompatible with a static binary lens, but are well fit by a...
This work explores the use of big data technologies deployed in the cloud for processing of astronomical data. We have applied Hadoop and Spark to the task of co-adding astronomical images. We compared the overhead and execution time of these frameworks. We conclude that performance of both frameworks is generally on par. The Spark API is more flexible, which allows one to easily construct astr...
The astronomical database SIMBAD developed at the Centre de Donn ees de Strasbourg CDS currently contains about one million objects stellar and non stellar all described by heterogeneous data bibliographical references measurements and identi ers SIMBAD supplies the existing links between the di erent synonym names of one object and describes astronomical objects with information coming from th...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید