Uv Astronomy

We compare the Astro-1 Ultraviolet Imaging Telescope (UIT) deep image of the Fornax cluster with deep optical surveys for purposes of determining the efficacy of vacuum ultraviolet imaging in terms of the recovery of very faint and/or diffuse galaxies. This field covers approximately 1/3 of a square degree and contains 15 galaxies with B t brighter than 18.0 mag. A 1000 s near-UV image detected ten of these galaxies. These ten detections include three luminous ellipticals, two bonafide dwarf ellipticals, and five galaxies of small angular size that may or may not be members of the Fornax cluster. If these optically faint galaxies are members of the Fornax cluster, then the VUV imaging did sample an appreciable range in the galaxy luminosity function. For the dwarf ellipticals, a comparison of their optical and UV fluxes indicates the UV light is not dominated by any hot population but rather represents the general UV characteristics of the underlying stellar population. In particular, we can place an upper limit of 25 03-5 stars that are present due to possible low level star formation. Furthermore, the UV-optical colors of the dFs are significantly redder than Galactic globular clusters which indicates that these dFs do not have a significant population of extreme horizontal branch stars. With the failure of the near-UV camera aboard the Astro-2 mission, the opportunity for performing a deeper near-UV survey has been lost. We conclude, however, that such a survey would have good sensitivity to the detection of optically faint and/or diffuse galaxies and would provide credible information on the galaxy luminosity function.

Abstract. The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA's scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and ...

The astronomical ultra-violet space telescope, TAUVEX, being developed in Israel by EL-OP Ltd., in conjunction with Tel Aviv University's Dept. of Astronomy and Astrophysics, has three co-aligned 20 cm diameter telescopes, each with an imaging photon-counting detector of ...

... Ana I. Gómez de Castro · Jesús Maíz · Pablo Rodriguez · Maite Gómez · Juan A. Larruquert · José A. Méndez · Tomas Belenguer · Victor Rodrigo-Gudiel · Fátima López ... AI Gómez de Castro ( ) · V. Rodrigo-Gudiel · F. López-Martínez · P. Sestito Fac. ... (2011), Goicoechea et al. ...

ISSIS is the Imaging and Slitless Spectroscopy Instrument for the World Space Observatory-Ultraviolet (WSO-UV) mission. ISSIS is a multipurpose instrument designed to carry out high resolution (<0.1 arcsec) imaging in the far UV with fields of view ≥2×2 arcmin2. ISSIS has two acquisition channels: the High Sensitivity Channel (HSC) and the Channel for Surveys (CfS). The HSC is equipped with an MCP-type detector to guarantee high sensitivity in the 1150-1750 Å range and high rejection of lower energy radiation. The CfS is equipped with a large CCD detector (4k×4k) to obtain images from the far UV to the red (1150-8500 Å); the CfS is implemented to allow observing UV bright sources such as reflection nebulae or nearby massive star forming regions. The design drivers and the current status of the instrument are described in this contribution.

Noah Brosch,1 Eran O. Ofek,1 Elhanan Almoznino,1 Timothy Sasseen,2 Michael Lampton3 and Stuart Bowyer3 ... 1The Wise Observatory and the School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel ...