4 research outputs found
UV and EUV Instruments
We describe telescopes and instruments that were developed and used for
astronomical research in the ultraviolet (UV) and extreme ultraviolet (EUV)
regions of the electromagnetic spectrum. The wavelength ranges covered by these
bands are not uniquely defined. We use the following convention here: The EUV
and UV span the regions ~100-912 and 912-3000 Angstroem respectively. The
limitation between both ranges is a natural choice, because the hydrogen Lyman
absorption edge is located at 912 Angstroem. At smaller wavelengths,
astronomical sources are strongly absorbed by the interstellar medium. It also
marks a technical limit, because telescopes and instruments are of different
design. In the EUV range, the technology is strongly related to that utilized
in X-ray astronomy, while in the UV range the instruments in many cases have
their roots in optical astronomy. We will, therefore, describe the UV and EUV
instruments in appropriate conciseness and refer to the respective chapters of
this volume for more technical details.Comment: To appear in: Landolt-Boernstein, New Series VI/4A, Astronomy,
Astrophysics, and Cosmology; Instruments and Methods, ed. J.E. Truemper,
Springer-Verlag, Berlin, 201
Dust in a Hostile Environment: Interstellar Dust in the Line of Sight to HD62542
Original paper can be found at: http://www.astrosociety.org/pubs/cs/070-112.html--Copyright Astronomical Society of the PacificHD 62542 is situated in a line of sight toward a ridge of dark matter in the Gum Nebula. That region is under the influence of UV radiation and stellar winds from hot stars. We use for the first time interstellar polarization and extinction data from the ultraviolet to the infrared in order to study and quantify the influence of such an environment on the size of the dust particles