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. ...