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SMA News and Events: 2008
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SMA News and Events: 2008
December 11, 2008
Circumstellar Shells of Gas
Science Update
SAO's Submillimeter Array (SMA) is the first facility capable of obtaining both very high spatial resolution imaging and precise velocity information at submillimeter wavelengths where many of these molecules emit their radiation. A team of nine SAO astronomers led by Nimesh Patel, along with two colleagues, have just published the first two articles in a pioneering series on the molecular envelope in CW Leo.
December 4, 2008
Brown Dwarfs Do From Like Stars
News Release: Science Daily
Using the Smithsonian's Submillimeter Array (SMA), they detected molecules of carbon monoxide shooting outward from the object known as ISO-Oph 102. Such molecular outflows typically are seen coming from young stars or protostars. However, this object has an estimated mass of 60 Jupiters, meaning it is too small to be a star. Astronomers have classified it as a brown dwarf.
November 27, 2008
Ultra-Luminous Infrared Galaxies
Science Update
Ultraluminous infrared galaxies ("ULIRGs") shine with the luminosity of one hundred or more Milky Way galaxies. Their most striking feature, however, is not their tremendous energy output but the fact that nearly all of their radiation is invisible, lying at infrared wavelengths. The source of this energy is intense star formation, and because that activity takes place within dust-filled clouds, the ultraviolet and visible light generated is absorbed by the dust grains and remitted in the infrared.
November 20, 2008
Submillimeter Eagle Eyes on Mauna Kea
News Release
The eSMA connects the signals from the Submillimeter Array (SMA), consisting of eight dishes with 6-meter diameter, with those from the 15-meter James Clerk Maxwell Telescope (JCMT) and the 10-meter Caltech Submillimeter Observatory (CSO) through fiber-optic cables. During observations the signals from all ten dishes are electronically combined in a large special-purpose computer to create a virtual telescope with a diameter of 782 meters, allowing for an exceptionally sharp view.
November 20, 2008
Colliding Galaxies in the Early Universe
Science Update
The universe contains many fabulously luminous galaxies, some of them more than a thousand times brighter than our own Milky Way. Most of them are practically invisible at optical wavelengths, however, because their light is predominantly at infrared wavelengths, and comes not from stars but from warm dust.
November 06, 2008
Studying a Young Solar System
Science Update
Last week a team of twelve astronomers including CfA astronomers Massimo Marengo, David Wilner, Tom Megeath and Giovanni Fazio announced the results of their combined infrared and submillimeter wavelength study of the dust disk in Epsilon Eridani. They used five different instruments to probe the nature of the emission.
October 16, 2008
Colossal Black Holes Common in the Early Universe
News Release
Astronomers think that many - perhaps all - galaxies in the universe contain massive black holes at their centers. New observations with the Submillimeter Array now suggest that such colossal black holes were common even 12 billion years ago, when the universe was only 1.7 billion years old and galaxies were just beginning to form. The new conclusion comes from the discovery of two distant galaxies, both with black holes at their heart, which are involved in a spectacular collision.
October 16, 2008
Double Jets in Young Binary Stars
Science Update
Most stars the size of the sun or larger (in mass) are part of multiple stellar systems in which two or even three stars orbit around one another. This tendency presumably reflects the conditions that existed when stars were born, since it is unlikely that stars pair up later on in their lives. The local conditions during star formation in turn reveal the complex environments when planets (if there are any) form around these stars.
October 09, 2008
The Double Nuclei of a Pair of Colliding Galaxies
Science Update
The galaxy Arp 220 is actually two galaxies that have been caught in the act of merging. Astronomers think that many galaxies, including our own Milky Way, have undergone similar collisions during their histories. Although the process of galaxy collision is important and common, what happens during these encounters is not very well understood.
September 11, 2008
The Milky Way's Super Massive Black Hole
Science Update
Black holes are by far the "simplest" objects in the universe because they can be completely characterized by just three numbers: their mass, electric charge, and spin. Although they are simple - or perhaps because of it - they are remarkably mysterious, in part because they are impossible to see directly. They are irresistible sinks for matter and energy, surrounded by a zone (the "event horizon") within which anything that ventures will inevitably fall and disappear, even light.
September 03, 2008
Closest Look Ever at the Edge of a Black Hole
News Release
Astronomers have taken the closest look ever at the giant black hole in the center of the Milky Way. By combining telescopes in Hawaii, Arizona, and California, they detected structure at a tiny angular scale of 37 micro-arcseconds - the equivalent of a baseball seen on the surface of the moon, 240,000 miles distant.
March 04, 2008
Donut Holes in the Young Solar System
Science Update
The CfA's Submillimeter Array (SMA) is uniquely suited to probe the very small distance scales associated with dust gaps in preplanetary disks. Two SAO astronomers, Charlie Qi and David Wilner, together with three colleagues, used the SMA to obtain some of the first direct images of a donut hole: the cleared annulus in a dust disk around one suspicious disk with a suggestive infrared spectrum.
February 12, 2008
The Birth of a Stellar Cluster
Science Update
A team of fifteen scientists led by SAO astronomers Rob Gutermuth, Tyler Bourke, Lori Allen, Phil Myers, and Tracy Huard combined the resources of the Spitzer Space Telescope and the Submillimeter Array (SMA) to discover a very young, dense cluster of new stars in one of the closest nurseries, in the constellation of Serpens.
February 05, 2008
Ammonia in Dark Clouds
Science Update
In 1969, astronomers discovered that ammonia (NH3) was present in large quantities in interstellar gas clouds. The species was most apparent in regions of star formation where the density and temperature of the gas enabled it to emit bright radio-wavelength radiation. Since then, ammonia has become one of the staple diagnostic probes of the regions where new stars are forming.
January 08, 2008
Spiraling Jets in New Stars
Science Update
Astronomers have come to realize during the past decade that most newborn stars are surrounded by disks of gas and dust, material that both helps the young star to grow, and that might evolve into planets around the star. No one yet knows exactly how or when these disks originate, but gravity begins assembling them sometime even before the star itself starts to burn its nuclear fuel.
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