|
|
|||
|
|
|
|
|
|
||||
|
Company History Key People News Customer Profiles Contact Us Employment |
Category: Astronomy Astronomers Search for Primeval Galaxies Marshall McCall and Michael De Robertis, Department of Physics and Astronomy, York University in Toronto, Canada, are using Data Desk to search for "primeval" galaxies, i.e. those galaxies which were the first to form after the universe itself came into being. Their mission takes them on explorations through measurements of colors for thousands of celestial objects.
McCall and De Robertis hypothesized that the first galaxies should emit certain colors of light less strongly than nearer galaxies. They predicted that measurements of the brightness of galaxies in four special colors would be sufficient to distinguish the "needle" of a primeval galaxy from the "haystack" of nearer objects.
Unfortunately, the candidates are so faint that they can't be studied readily with facilities to which McCall and De Robertis presently have access. Colleagues at the 10-meter Keck Observatory kindly attempted to acquire a measurement of one object, but weather problems severely limited the time that could be spent observing. Shortly, though, the brand new 8-meter Gemini telescope in Hawaii will be open for observing. Because Canada is a participant, it will be possible for McCall and De Robertis to carry out their own measurements of the velocities of the primeval galaxy candidates. Furthermore, because the new telescopes are capable of collecting enormous amounts of data in a very short time, searches for primeval galaxies can be expanded drastically. Data Desk will continue to be an integral part of their investigations. |
Name: Marshall McCall and Michael De Robertis Affiliation: York University, Dept. of Physics and Astronomy Location: Toronto, Canada Version: Data Desk 6.0, Windows 95 Typical Dataset: 6,000 points Analysis: Selection and highlighting on the basis of color criteria. |
|||
|
|||||
|
|
|||||
To
find a primeval galaxy, it is necessary to search for the most
distant galaxies in the universe. The more distant a galaxy, the
longer its light has taken to reach us, and the farther back in time
we see it. More distant galaxies are fainter. But there are nearby
galaxies which are faint, too. To identify a faint galaxy as being
distant, it is necessary to search for a special color signature
which distinguishes it from objects which are nearby.
Using
the Canada-France-Hawaii Telescope and a camera equipped with
custom-made filters carefully tuned to admit the selected colors,
they recorded light from nearly 6,000 celestial objects. Using Data
Desk, they were able pinpoint 8 primeval galaxy candidates. However,
to definitively prove whether or not the candidates are indeed
primeval, it will be necessary to acquire measurements of how fast
they are moving away from us as a consequence of the expansion of the
universe. Knowing the speeds of recession, it will be possible to
evaluate their distances, and thereby determine whether or not the
faintness of the candidates is really due to them being far away.