ar X iv : a st ro - p h / 03 11 51 7 v 1 2 2 N ov 2 00 3 Cryogenic Tests of Volume - Phase Holographic Gratings : I . Results at 200 K

ar X iv : a st ro - p h / 06 09 06 9 v 1 4 Se p 20 06 Cryogenic tests of volume - phase holographic gratings : results at 100 K

We present results from cryogenic tests of Volume-Phase Holographic (VPH) gratings at ∼ 100 K. The aims of these tests are to see whether the diffraction efficiency as a function of wavelength is significantly different at a low temperature from that at room temperature and to see how the performance of a VPH grating is affected by a number of thermal cycles. We have completed 10 cycles between...

ar X iv : a st ro - p h / 03 11 44 5 v 1 1 9 N ov 2 00 3 Multiscale self - organized criticality and powerful X - ray flares

A combination of spectral and moments analysis of the continuous X-ray flux data is used to show consistency of statistical properties of the powerful solar flares with 2D BTW prototype model of self-organized criticality.

ar X iv : a st ro - p h / 03 11 60 3 v 1 2 7 N ov 2 00 3 A search for emission line galaxies at z = 6 . 5

We are carrying out a search for Lyα emitting galaxies at z = 6.5 employing slitless spectroscopy at the VLT. In our 43 arcmin field we find three isolated single emission lines with SEDs consistent with line emitting galaxies at z = 6.5.

ar X iv : a st ro - p h / 01 11 13 6 v 1 7 N ov 2 00 1 1 Active Optics in Modern , Large Optical Telescopes

ar X iv : a st ro - p h / 02 11 45 7 v 1 2 0 N ov 2 00 2 Time variation of fundamental constants : two phenomenological models

Time variation of fundamental constants, a strong signal of new physics, is analyzed comparing extant data with two phenomenological models. Results are discussed.