Summary of Scientific Results - 2006
Subaru Telescope completed another year of observations using sophisticatedinstrumentation that allowed for discoveries of significant import. Studies werecompleted within our Solar System and Galaxy, and, most impressively, at theedge of known space. Subaru also welcomed in a new and improved adaptive
optics system that opened up portions of the sky never viewed before. Theseand other amazing events all took place at Subaru during 2006.
This year, the state-of-the-art adaptive optics (AO) system was upgraded andimproved by a factor of ten. AO removes the twinkle and eliminates the blur fromvisible and infrared observations. The original system was made up of 36
elements, while the new system delivers sharper images because it uses 188
elements, allowing for the correction of more subtle distortions. The new system
improves image resolution of fainter objects under worse weather conditions.
The new AO system allows the telescope to operate at its theoretical resolving
power. Concurrently with the new AO system, Subaru developed and installed a
new laser guide star system that allows astronomers to create an artificial star
anywhere in the sky. The new systems enable astronomers to study objects
previously unobservable and do so with more detailed imaging andspectroscopy.
As with previous years, Subaru set milestones with the discovery of moresatellites around Saturn. An astronomer from the University of Hawaii, who is thepreeminent explorer of planetary satellites, used the Subaru telescope to find 9
new moons around Saturn. Along with this discovery, Japanese astronomers
imaged comet Schwasmann-Wachmann 3 as it passed close by and crumbled
into more than 50 pieces. Their study showed how dirty ice balls called comets
fall apart, which, in turn, will enable astronomers to find out how comets stay
together.
Some of the research conducted at Subaru focuses on stars within our own
galaxy to better understand the formation and evolution processes of stars andplanets. The investigation into proto-planetary disks around two nearby stars
revealed some astonishing findings. Star Beta Pictoris, a scant 60 light years
away, was studied with infrared polarization for the first time to achieve better
resolution and higher contrast. The images suggested that the disk around Beta
Pictoris contains planetesimals, asteroid or comet-like objects, that collide togenerate dust that reflects starlight. Another team of astronomers found thatstar, HD142527, exhibited a shape never seen before in a proto-planetary disk; it
has two banana-shaped arcs facing each other rather than the donut or spiralshape commonly seen. The odd shape may be explained by the presence of adim companion star or possible planet. A study similar to these two
aforementioned, is the exploration into another young star HD 141569A and its
circumstellar disk, an area providing raw material for the creation of planets.

Astronomers found that the star has abruptly developed a hole at the center of its
disk through photo-evaporation larger than the orbit of Saturn. When and how adisk dissipates has direct consequences on the probability of a planet forming
around the nearby star.
An interesting phenomenon that captures everyone’s imagination is a black hole.
We know that one lays at the center of the Milky Way Galaxy and almost every
other galaxy. New observations by a research group led by a Japanese
astronomer discovered that active super-massive black holes can be completely
surrounded by dust, obscuring their presence from detection in all directions.
The group confirmed that this type of black hole could account for the bulk of theinfrared luminosities from merged gas-rich spiral galaxies.
This year, as in previous, much focus was put into research towards the knownedge of the Universe. One study, led to the discovery of a large number ofgalaxies that existed when the universe was less than a quarter of its current
age. The team calculated how the life-cycle of stars and mergers of earlygalaxies lead to the formation of galaxies we see today. Another team,discovered three-dimensional filaments extending across 200 million light-yearsof space in galaxies that formed 12 billion years ago. These filaments are thelargest known structures ever discovered, and are probably the progenitors of themost massive galaxies that exist today. Not to be outdone in distance, aJapanese astronomer found the eleventh most distant quasar currently known at
12.7 billion light years away. Quasars are rare events and consist of a huge
outburst of gravitational energy from matter that is falling into a very massive
black hole. Just a little further away, gamma-ray burst GRB 050904 wasanalyzed by Subaru to show that more than 80% of the hydrogen betweengalaxies was already ionized only 900 million years after the birth of theUniverse. Finally, the most distant and earliest known galaxy, IOK-1, wasobserved by Subaru astronomers as it appeared 12.88 billion years ago. The
discovery showed astronomers that we are viewing the reionization of theUniverse, which indicates that we are excavating into the “Dark Ages” of theUniverse when the first generation of stars and galaxies came into existence.