Weak lensing studies typically require excellent seeing conditions for the purpose of maximizing number density well-resolved galaxy images. It is interesting to ask what extent size limits usefulness astronomical images in weak lensing. In this work, we study issue with data DECam Legacy Survey (DECaLS), which a part target selection program Dark Energy Spectroscopic Instrument (DESI). Using F...

We propose a new instrumental concept for long-baseline optical single-mode interferometry using integrated optics which were developed for telecommunication. Visible and infrared multi-aperture interferometry requires many optical functions (spatial filtering, beam combination, photometric calibration, polarization control) to detect astronomical signals at very high angular resolution. Since ...

An important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak Doppler shifts in the spectra of host stars induced by the influence of orbiting planets. A recent advance has been the introduction of optical frequency combs as frequency references. Frequency combs produce a series of equally spaced reference frequencies and they offer ex...

The launch of the Chandra (NASA) and XMM-Newton (ESA) X-ray observatories in 1999 has revolutionized our view of the Universe, by providing astro-physical information about many classes of sources with unprecedent detail. The high throughput of XMM-Newton makes it the ideal instrument to provide low to moderate resolution spectroscopy of faint and extended sources. After 3 years of operations, ...

The Receiver Lab Telescope (RLT) is a groundbased terahertz telescope; it is currently the only instrument producing astronomical data between 1 and 2 THz. The capabilities of the RLT have been expanding since observations began in late 2002. Initial observations were limited to the 850 GHz and 1.03 THz windows due to the availability of solid state local oscillators. In the last year we have b...

Coded mask imagers are among a class of high energy astronomical instruments in which spatial or temporal coding, or a combination of the two, allows ‘multiplexing’ of the detection process. In this way many ‘pixels’ of an image can be observed and measured simultaneously. In certain circumstances this gives an advantage in signal to noise ratio, compared with an alternative approach in which e...

The MDM/Ohio State/ALADDIN Infrared Camera (MOSAIC) is a general purpose near infrared (0.9-2.5 micron) imaging camera and medium-resolution (R=1300) long-slit spectrometer in use on the MDM 1.3-m and 2.4-m telescopes and the Kitt Peak 2.1-m and 4-m telescopes. In cooperation with NOAO and USNO, MOSAIC is one of the first general-purpose near-IR instruments available to the astronomical communi...

The high quality of the AXAF X-ray data provides new challenges for the X-ray data analysis. It is clear that an “old” approach is not enough to fully exploit the capabilities of the AXAF instruments. We describe a few of the statistical and computational problems that we have so far identified. Some of them appear to be theoretically solvable but computationally challenging, while others state...

The perfect site for astronomical interferometry would be one where the wind speeds throughout the atmosphere were very low, there was little atmospheric turbulence (especially at high altitudes), the seismic activity was negligible and the climate very stable. Perhaps surprisingly, these conditions describe the Antarctic plateau perfectly. At Dome C, for example, the average wind speed at grou...

The IAU-1976 System of astronomical constants includes three astronomical units (i.e. for time, mass and length). This paper reports on the status of the astronomical unit of length (ua) and mass (MSun) within the context of the recent IAU Resolutions on reference systems and the use of modern observations in the solar system. We especially look at a possible re-definition of the ua as an astro...