Next: Catalog Construction Up: Observations and Analysis Previous: Source Detections . ... It was assumed that the highest signal gives the most likely position of the source. ... Comparing the summed map with the maps from the individual energy ranges, the one which produced the smallest error box was chosen to represent the source position, as long as was greater than 4, a level chosen to reflect a reasonable degree of confidence in the detection. ...

This page holds the archived system performance data (the current data is on the system performance page) . ... Gain,Tsys,Sefd.. Coma,sidelobes, beam efficiency . Pointing errors. Az,za coverage . Hour of day when sources measured. 01sep01 thru 30jul02 (cooled receiver to - room temp amps installed) . ... Hour of day when sources measured (.ps) (.pdf) . ... Hour of day when sources measured. 21aug02 thru 01feb03 (horn focus change to reshimming of elevation rails, pointing model). ...

... This chapter discusses some of the error sources associated with WFPC2 data. Most of the chapter focuses on specific calibration errors, complementing and partially overlapping the discussion given in "Improving the Pipeline Calibration in section 3.5 . ... Note that many of the error sources affecting calibrated WFPC2 data can be reduced by either recalibration with newer reference files or post-pipeline improvements, such as correction flatfields (see section 3.5.2 ). ...

... Meta Index / Home Page This section documents warnings and errors generated by this task (if any). ... error . ... The instrument recorded in the source list header keyword INSTRUME is not the same as that derived from the value of the instexpid parameter. corrective action: The task uses the value from the source list header. expIdStrClash . ... If clobberonlabel =no, this condition causes the task to fail with an error. corrective action: New source is not appended to the source list. outsideFOV ....

... A comparison of the computed and experimental relations F max ( H), as well as comparison of drift scans of point sources across different horizontal cross-sections of the BP with the corresponding computed cross-sections were made. ... The drift scans of the point source 3С84 (H=87 o ) at the wavelength 7.6 cm across the horizontal cross-sections of the BP (black lines) and the computed horizontal cross-sections of the BP corresponding to them (red lines). ...

... Optical photometric data were taken of fields encompassing all these sources during a total of seven telescope runs. ... The initial goal of the photometric observations is to follow up the X--ray sources, assign them colors in a standard system, so that the observed objects can be placed on a color--magnitude diagram. This can be used to verify that the X--ray sources are indeed PMS stars. ... Aperture photometry was performed using the APPHOT package in IRAF. ...

Since the 1980s VLBI observations at two frequencies, 8.4 (X-band) and 2.3 GHz (S-band) have been used to locate the positions of compact radio sources with unprecedented accuracy. ... Observations of selected strong compact extragalactic radio sources, using this now mature technique, have been used to define and maintain a radio reference frame with sub-milli-arcsecond (mas) precision. ... Additionally, it will provide more reference sources for phase referencing VLBI observations. ... References . ...