Next: Artifacts Up: Computational Methods Previous: Estimation . The actual transformation of raw detector data to clean maps in intensity scale depends strongly on both the imaging and detecting systems. However, three typical steps can be identified, namely: detection and removal artifacts in the data, correction for non--linear effects or relative variations in sensitivity of the detector system, and correction for geometric distortions in the imaging device. ... Response Calibration . ...

... This paper describes distortion calibration procedures for the SOHO /LASCO-C2 Coronagraph, based on in-orbit data and extensive image processing methods. ... C2 suffers from moderate optical distortion, which must be corrected in order to properly locate the stars crossing its field-of-view (which are subsequently used for photometric calibrations), to retrieve critical attitude parameters, and to insure a correct overlapping of the region common to the C2 and C3 instruments. ...

Fermi s Gamma ray Pulsars . ... Traditionally identified and studied by observing their regular radio pulsations , two dozen pulsars have now been detected at extreme gamma-ray energies by the Fermi Gamma-ray Space Telescope . ... This gamma-ray all-sky map, aligned with the plane of our Milky Way Galaxy, shows the pulsar positions, with the 16 new Fermi pulsars circled in yellow (8 previously known radio pulsars are in magenta). ... NASA Web Site Statements, Warnings, and Disclaimers . ...

Next: Identifications and Efficiency Up: THE DEEP X-RAY RADIO Previous: Source Classification . ... For some sources which did not have NVSS positions before the time of optical observations, arcsecond positions from the Texas survey (Douglas et al. 1996) and NED (typically based on VLA data) were used. ... All X-ray/radio sources without counterparts on the survey plates were imaged at either the KPNO 0.9m or the CTIO 0.9m telescopes. ... Previously Identified Sources . Sample Properties . ...

Next: References Up: No Title Previous: Observational data and reduction . ... A minor loss of information is due to the overestimation of the scattered light in the region of and to the broad emission lines and . On the diagrams are shown the blue-shifted absorption lines and the interstellar diffusion bands. ... In Table 1 are given only emission lines. Questionable features and the lines that fell within the gaps are not included in it, question-marks are for unreliable identification. ...

Dear PALFA consortium members, Another smooth day of observing, with detections of J1928+1746 (PALFA#1), a much brighter re-detection of B2020+28, a few single-pulse candidates, and not much else to report from our quicklook. ... Update databsae with fill_observed.py Quicklook Notes: * Plot order bug: displays candidate 1, 10, 2, 3, .. Plot display bug: If the last candidate (#9 for now) is filtered out, then the single pulse plot is also filtered out. ... No other obvious quicklook candidates. ...

. Home . News . Gallery . Events . Twitter . Press Releases . Links . Contact Us . Calendar . Press & Web Coverage . Previous . Next . List . Taken on the 24th November by John McConnell. It shows the ISS and an unidentified satellite . Friday, 2 January 2009 23:14 . International Year of Astronomy, Ireland National Node . [Back To Top] .

... In order to obtain a quantitative estimate of the accuracy and reliability of our data reduction procedures and results, we have performed a data reduction pipeline based on the following steps: i) define a set of simulated HST-like images with synthetic globular cluster stellar distributions, which provide the ``true'' data for comparison; ii) convolve these images with appropriate assumptions of PSF and noise in order to construct simulated `` observed '' ... It contains 470 stars. b) ...