NAOJ Press Releases 2007
NAOJ Press Releases 2007
A team of Japanese astronomers from the National Astronomical Observatory of Japan, Tokyo University, and Kyoto University in Japan obtained deep and high-resolution images of galaxies from 11 billion years ago using the adaptive optics (AO) system and the infrared camera and spectrograph (IRCS) on the Subaru Telescope. Thanks to the removal of atmospheric blur by the AO system, high spatial resolution imaging was achieved in the near-infrared and the profiles of the distant galaxies were revealed. The images of the distant galaxies show almost all of the galaxies have a light profile similar to the disk galaxies in the local universe.
Hinode (SOLAR-B) has brought us a new perspective of solar physics since its launch on September 22, 2006.
Sience magazine, one of the leading journals of scientific research, features Hinode discoveries. An impressive picture obtained with Hinode appears in the front page of the journal. This press release highlights two of nine articles published in the special issue.
An team of 15 astronomers observed the spheroidal dwarf galaxy Leo II and found that the galaxy is more extended than previously thought and established a star-formation history of this galaxy.
When meteoroids flash through the Earth’s atmosphere, they bore tunnels through the air, leaving behind narrow meteor tracks that are heated by the collision of the fast-moving incoming object with atoms of highly diluted atmospheric gases. Most meteoroids are bits of space debris the size of a grain of sand. The width of the tracks they make has long been known to be narrower than a meter, but until recently, more precise measurements have been impossible to make.
A Japanese/US collaboration led by a researcher from the University of Tokyo observed the transiting extrasolar planetary system TrES-1 and measured the angle between the stellar spin axis and the planetary orbital axis using the Subaru Telescope High Dispersion Spectrograph (HDS). By measuring the degree of alignment in transiting systems, one can constraint planetary formation models proposed to explain the diverse properties of extrasolar planets. It was the third case and the faintest target so far for which the spin-orbit alignment has been measured.
VERA (VLBI Exploration of Radio Astrometry) has demonstrated its high capability of precise astrometry by breaking the world record of the largest distance measured by means of trigonometric parallax as well as by providing the best distance measurement for Orion KL, one of the most important Galactic objects.
Astronomers from the National Astronomical Observatory of Japan and Osaka Kyoiku University in Osaka, Japan, have detected the elementthorium in a red giant star called COS82, which lies in the Ursa Minor dwarf galaxy. Their discovery marks the first abundance determination of the actinides element thorium in a star beyond the Milky Way, and follows the detection of thorium in more than ten stars within the Milky Way. The derived thorium abundance indicates that the explosive synthesis of heavy elements occurs in similar-type environments in both the Milky Way and the Ursa Minor dwarf galaxy, which is a satellite of the Milky Way.
All the data obtained with Hinode have become open to public on 27th May, 2007. Tremendous data have been obtained with three telescopes on Hinode since their first lights in October 2006. We prepared a long-term movie of full Sun images taken with XRT to demonstrate the evolution of dynamic corona.
Cometary nuclei are believed to contain important information on the condition of the solar nebula, but there is little observational data available on their interior structure. Our ground-based observations of NASA’s Deep Impact event show that comet 9P/Tempel 1 has a surface layer consisting of small (sub-micron sized) carbonaceous grains whose thickness is several tens of cm. This suggests that comet 9P/Tempel 1 contains at several tens of cm of depth material that has not metamorphosed since this comet left the trans-Neptunian region. This further implies that many short-period comets may maintain the components they had upon leaving the trans-Neptunian region at ~ 1 m of depth from the surface even after numerous perihelion passages.
Precise analysis of a high-resolution image of Comet 73P/Schwassman-Wachmann 3 (SW3) taken in May 2006 by the Subaru Telescope, reveals that one chunk called Fragment B is split into at least 50 fragments. This is well more than the 13 estimated when the image was first released in 2006.
Researchers from the University of Toyama and Nobeyama Radio Observatory, NAOJ have assigned 7 unidentified lines in Orion KL from previous line surveys around 97 GHz with Nobeyama 45 m radio telescope to the first torsionally excited methyl formate (Kobayashi et al. 2007 ApJL 657, L17). Recent progress on the assignment of laboratory spectra of methyl formate made it possible the successful assignments and in addition, at least 13 lines from other line surveys were also identified. The detection helps to estimate the temperature and the abundance of this molecule and chemical reaction where the radio signal comes from. It is quite likely that many unidentified lines can be explained by this kind of organic molecules in the torsionally excited states.
Hinode (Solar-B) successfully captured a massive flare occurred in active region NOAA 10930 on 13 December 2006. It was one of the largest flares occurred in the period of solar activity minimum.
Data obtained with three telescopes on Hinode are in good quality. X-ray Telescope (XRT) saw high temperature coronal loop and detected wave propagation associated with the flare. Solar Optical Telescope (SOT) found the collision of two spots well in advance of the flare, which implies the twisting of magnetic fields in the corona. Extereme-ultraviolet Imaging Spectrometer (EIS) detected supersonic eruption during the flare.
This is the first time to get high resolution comprehensive data set ranging from magnetic fields, which are the energy source of the flare, and dynamics of high temperature plasma produced by the flare. Hinode team is now intensively studying the precious data.
"Hinode" experienced total eclipse in orbit on 2007 March 19, while it was just a partial eclipse on the ground. These data are used to measure scatterd light of telescopes. X-ray Telescope (XRT) obtained full disk images during the total eclipse in soft X-ray images. Solar Optical Telescope (SOT) was pointed at disk center and witnessed shadow of mountains on the Moon.
A new image of the Crab Nebula supernova remnant taken using the Prime Focus Camera (Suprime-Cam) on the Subaru telescope highlights the beauty of stellar debris expanding away from the site of this ancient blast. The high-resolution image captures details of an elongated tendril of gas rushing out at roughly 1,500 kilometers per second. While the nebula has been observed many times using both ground- and space-based telescopes, this image is giving astronomers another opportunity to study the mechanics of the expanding gas in much greater detail.
Researchers from the National Astronomical Observatory of Japan (NAOJ) and the University of Tokyo used Subaru's Suprime-Cam camera to discover an unusual streak of ionized hydrogen gas associated with a galaxy 300 million light-years from Earth. The filament of gas is only 6 thousand light-years wide, yet extends 200,000 light-years, about the distance between the Milky Way Galaxy and its companion, the Large Magellanic Cloud. Finding such an extremely narrow and long ionized gas cloud is a first in astronomy.
Researchers from the National Astronomical Observatory of Japan (NAOJ) and the University of Tokyo used Subaru's Suprime-Cam camera to discover an unusual streak of ionized hydrogen gas associated with a galaxy 300 million light-years from Earth. The filament of gas is only 6 thousand light-years wide, yet extends 200,000 light-years, about the distance between the Milky Way Galaxy and its companion, the Large Magellanic Cloud. Finding such an extremely narrow and long ionized gas cloud is a first in astronomy.
An international research team from the University of Jena (Germany), Nagoya University, and the Harvard-Smithsonian Center (USA) recently obtained the first images of the second "sun" around a planet-hosting star, gamma Cephei, using the Subaru telescope and the 3.5-meter telescope at Calar Alto (Spain). This direct detection significantly improves our knowledge of the system, such as the masses of the two stars and the minimum mass of the planet.
( >> See Calar Alto Astronomical Observatory Homepage for More Details )
An international team of astronomers led by Nick Scoville from the California Institute of Technology have created a three dimensional map that provides the first direct look at the large-scale distribution of matter in the universe. This is best evidence yet that normal matter, like stars and galaxies, accumulate along the densest concentrations of invisible dark matter. The map extends to a time when the universe was only half its current size and shows that dark matter has grown increasingly clumpy, forming long flamentary structures. Observations with the Subaru telescope, led by Yoshiaki Taniguchi from Ehime University, contributed the 3D distanzce and time information. Details are in a paper by Richard Massey et al. in the journal Nature (January 7, 2007 edition).
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