Space Telescope Science Institute . ACS Instrument Handbook Cycle 19 . ... Advanced Camera for Surveys Instrument Handbook for Cycle 19 > Chapter 9: Exposure-Time Calculations > 9.3 Computing Exposure Times . 9.3 Computing Exposure Times . ... Expected counts C from your source over some area. ... The detector background, or dark, ( B det ) in counts/second/pixel and the read noise ( R) in counts of the CCD. ... You must remember to multiply by G to compute photon events in the raw CCD images. ...

... We have developed an integrated system that performs astronomical observations in Near Infrared bands operating two-dimensional instruments at the Italian National Infrared Facility's ARNICA and LONGSP . ... The user interface is organized as widget-based X11 client. ... 1993; Di Giacomo et al. 1993). ... Moreover, if the interprocess communication interface includes support for networking, the software immediately becomes network distributed software. ... DESQview/X User Guide 1993, Quarterdeck . ...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

... Calculated exposure times do not take into account instrument and telescope overheads. ... The reference area for the S/N is circular with a radius equal to FWHM of the Image Quality PSF at the airmass and wavelength of observation. ... begin{equation} \mathit{FWHM}_{\text{IQ}} = \sqrt{\mathit{FWHM}_{\text{atm}}^2(\mathit{s},x,\lambda)+\mathit{FWHM}_{\text{tel}}^2(\mathit{D},\lambda)+\mathit{FWHM}_{\text{ins}}^2(\lambda)} \end{equation} } \) . ... The Exposure Time is the product of DIT and NDIT . ...

XMM-Newton Science Analysis System Page: 1 rgsbkgmodel June 28, 2006 Abstract Compute a model background spectrum from RGS background templates 1 Instruments/Modes Instrument Mode RGS Spectroscopy 2 Use In the interactive environment. pipeline processing no interactive analysis yes 3 Description The aim of this package is to compute a model spectrum of the RGS background applicable to a given observation from a combination of observations of empty elds. ... Model background spectra (OGIP-compliant). ...

... There are compelling reasons for the pulsar community to utilise a standard data storage format. For example, standardisation of file formats significantly decreases the amount of effort required to integrate new instruments into the analysis chain. ... Accordingly, we have defined PSRFITS as a standard FITS-based format for pulsar data files. ... For example, the first line of Processing History HDU contains information about the data acquisition program and the initial structure of the file. ...

Next: Model Spectra for Spectral-Fitting Up: Spectral Analysis Previous: A Quick Look at . ... For ROSAT PSPC data, this conversion is done during the on-line (SASS) processing. For IPC observations, the instrument gain varies both across the detector and in time, and is applied during off-line processing (PROS) using the BAL histogram. By default, spectra are extracted in PI bins for PSPC data and in PHA bins for IPC data. ... Special techniques are required when using Einstein IPC data. ...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Mati†иre noire : une observation d†йfie les astronomes . ... A la une . ... En effet, selon les mod†иles th†йoriques, les concentrations de mati†иre noire sont les lieux o†µ naissent les galaxies. ... Une mati†иre noire au comportement ordinaire ? ... Etat du ciel . ...

... The SMS program is a critical endeavor to investigate whether the predictions of standard cold dark matter cosmology are consistent with the observed matter distribution in the Milky Way halo. It is the deepest, most extended search for optically elusive dwarf satellite galaxies and tidal streams to date, covering the entire Southern hemisphere. ... However only a few dwarf satellites have been found around the Milky Way to date - 22 dwarfs compared to 500-10,000 predicted by theory (Klypin et al. ...

Twilight observations with MASS/DIMM B. Safonov Sternberg Astronomical Institute Moscow State University Comprehensive Characterization of Astronomical Sites, 2010 B. Safonov (Moscow State University) Twilight observations with MASS/DIMM SITE 2010 1 / 17 Why observe in twilight with MASS/DIMM? ... ASM includes 3 devices sensitive to background: guider, DIMM and MASS. B. Safonov (Moscow State University) Twilight observations with MASS/DIMM SITE 2010 2 / 17 Background in guider. ...

... It consists of two energy-angle analyzers EA-2 and EA-3 for low energy particles, and two identical oppositely directed time-of-flight (TOF) analyzers EM-1-1 and EM-1-2 for high energies. ... Analyzers of low energy charged particles (EA-2 and EA-3). ... The instruments allow to measure simultaneously in eight angular sectors evenly distributed in the angle 2 perpendicular to the satellite rotation axis, and sequentially in 7 energy intervals for each angular sector. ... Interval . ...

... AMPLE (Adaptable Minor Planet Ephemerides) is integrated software package to deal with a number of problems concerning minor planets with the aid of IBM-type personal computer. ... compiling a list of all numbered minor planets which can be seen at certain moment within specified sky region and visualization of their mutual positions; . ... As AMPLE is able to reproduce virtually any table of "the Ephemerides of Minor Planets" , it may be considered as computer version of the EMP. ...

... Maps of 21cm emission are dominated by warm H i, and most observations of H i absorption against continuum sources are limited to discrete points. ... Current Results At right are maps of H i emission, HISA, and 12 CO emission in the eastern 25% of the survey, given as projections along the velocity (Figure 1) and latitude (Figure 2) axes. ... 2000, A. J., submitted Figure 1: H i Survey Map (`; b): H i 21cm brightness integrated over all velocity channels; white is bright and black is faint. ...

ION AND ELECTRON ENERGY DETECTOR PAN-2 . ... The energy and angular distributions of charged particles can bring further information on the nature and spatial scales of magnetospheres processes. ... It permits the fast measurements of energy and angular parameters of charged particles in the range 40eV-40keV. ... The sensor unit is an electron electrostatic, axially symmetrical, toroidal analyzer. ... The energy range for both types of charged particles must stepped according to the logarithmic scale. ...

... In brief: the frequency-dependent radiative transfer equation is solved for a dust under assumption of spherically-symmetric geometry for its distribution taking into account particle size distribution and quantum heating effects for the very small dust particles. ... Table: Model parameters for IRAS04296+3429. ... parameter . ... hot dust shell) . ... The best fit to the spectral energy distribution of IRAS04296 is shown by heavy solid line (see Table2 for details concerning parameters of the model...

... 1Becker A catalog of 53522 4.85 GHz sources between 0 and 75^o declination has been generated from observation taken with the NRAO Green Bank 300 foot (91m) telescope. The flux limit of the catalog is dependent on confidence radius of ~50". Spectral indices have been calculated for 29051 sources which have counterpart in the Texas 365 MHz northern sky survey. ... The rms noise in the images varied from 5 to 8 mJy. The images has an angular resolution of ~3.5'. ...

STEP INTO THE BLUE - MEADE INSTRUMENTS PRODUCT GUIDE . ... Telescopes . LX850 Series . ... Superb optical performance coupled with time proven computerized pointing and tracking has made the LX200 ACF series a best-seller in the high-performance telescope class. ... Meade's revolutionary LS LightSwitchтДв series of telescopes use advanced technologies to do what no other consumer telescopes have done before: take all the hassle out of using a telescope. ... Coronado€о Solar . ... Spotting Scopes . ...

... It was designed to observe the solar wind approaching Earth, from a position near the Lagrangian point L1, and it is part of the International Solar-Terrestrial Physics (ISTP) Initiative . ... The original plan called for "Wind" to approach its final station over two years, undergoing two close encounters with the Moon to boost its speed. ... If however the object is moving , the encounter is not symmetric, and in the end the spacecraft may have gained or lost speed, depending on its trajectory. ...