230 research outputs found
A massive disk galaxy at z>3 along the sightline of QSO 1508+5714
We have obtained deep images in the BVRIJHKs bands of the field centered on
QSO 1508+5714 (z_{em} =4.28) with the Suprime camera, FOCAS and MOIRCS cameras
on Subaru telescope. We report here the detection of a B-dropout galaxy, which
is 3\secpoint 5 north-west of the QSO sightline. A photometric redshift
analysis is presented to complement the color selection. Given the photometric
properties of this object (, making , if
placed at its photometric redshift ), as well as the
Srsic index () derived from a 2-D imaging decomposition
of the HST WFPC2 image taken in the filter, the identified system is
consistent with a massive disk galaxy at z>3. If confirmed, it would be one of
the most distant massive disk galaxies known so far.Comment: 12 pages, 6 figures, accepted by PASJ, Vol.61/No.5, 200
Three-Mirror Anastigmat Telescope with an Unvignetted Flat Focal Plane
A new optical design concept of telescopes to provide an aberration-free,
wide field, unvignetted flat focal plane is described. The system employs three
aspheric mirrors to remove aberrations, and provides a semi-circular field of
view with minimum vignetting. The third mirror reimages the intermediate image
made by the first two-mirror system with a magnification factor on the order of
unity. The present system contrasts with the Korsch system where the
magnification factor of the third mirror is usually much larger than unity. Two
separate optical trains can be deployed to cover the entire circular field, if
necessary.Comment: 13 pages, 6 figures, 2 table
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