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. ...

... The task first computes a background image in order to identify pixels that may be part of a source. The task uses two different algorithms for detecting ``point'' and ``extended'' sources. ... This is necessary because some faint ``point'' sources may have been missed by the point-source detection algorithm, but picked up by the extended-source detection algorithm. ... When the detection process is finished a check is made on extended sources to see if they can be split into two or more sources. ...

... Duchamp | ... Top | Duchamp is a solution to this problem of three-dimensional source finding. ... A list of the detections and their properties, as well as the input parameters that were used. [text file] . ... It can be downloaded in source format, in a gzipped tar archive. ... Changes from the previous version can be seen here (this file is included in the tar archive), while the archive files and documentation from the previous release versions are here , if you are really interested. ...

... The ROSAT Consortium (the Max-Planck-Institut fuer extraterrestrische Physik, the Goddard Space Flight Center, the Smithsonian Astrophysical Observatory, Leicester University, and the Astrophysikalisches Institut Potsdam) announces the release of the completed source catalogs of all ROSAT pointed observations. ... Detailed information about the catalog and methods of access to the catalog and data products can be obtained from the ROSAT Results Archive web pages in Germany, in the US, and in the UK:...

... WFPC2 ETC for Extended Sources + Background - v4.0 . Home . ... Data . ... WFPC2 Home . ... Instrument Home . WFPC2 History . ... Calibration Home . ... LRF Data . ... Data Analysis Home . ... ETCs . ... Brightness: (mag. arcsec -2 ) . ... Line: Ly 1216 C IV 1550 He II 1640 C III 1907 Mg II 2800 0 II 3727 Ne III 3869 H 4340 0 III 4363 He II 4686 H 4861 0 III 4959 0 III 5007 N II 5755 He I 5876 0 I 6300 N II 6548 H 6563 N II 6583 S II 6716 S II 6731 S III 9531 Specify Z Vel. : (units) . ...

... astro-ph . ... Statistical Characterization of the Chandra Source Catalog . ... The first release of the Chandra Source Catalog (CSC) contains ~95,000 X-ray sources in a total area of ~0.75% of the entire sky, using data from ~3,900 separate ACIS observations of a multitude of different types of X-ray sources. ... In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively. ...

... The generation of simulated sources whose physical properties are well understood is useful in assessing the functionality of point source analysis software. Qpsim is an IRAF/PROS task which will generate events from sources of given intensity, shape, and position and either overlay them on a flat background in a new QPOE file or inject them into an existing QPOE file. ... The simulated data can be a useful tool in calibrating point source analysis software. ...

... The derived position here agrees with the position from recent ATCA observations, RA=15h 01m 34.74s, Dec=39 18 39.2" (Tasker, private communication) which found the source unresolved. Because of the relatively large position offset, the reality of the fainter component 0.12" to the west is somewhat in doubt. However, the ATCA centroid position is offset by 0.3" to the south-east of the VLBA position, suggesting that the faint component may be part of more extended structure. ...

... Download the code document. A new version will be released soon with a more detailed document. An X-ray source detection algorithm, optimally designed to detected faint extended sources, making use of Voronoi tessellation and Friend-of-Friend technique. ... This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License. Download sweepline.py . ... ROSAT 400d . ROSAT MACS . ROSAT WARPS . ROSAT REFLEX . ... XMM XCS . ...

... During the analysis of the surveys carried out on RATAN-600, it was found that almost one fifth of the detected sources shows significant radio flux variations. ... We used the data from "Cold" radio surveys carried out with RATAN-600 in 1980-1994 to search for radio sources with significant flux variability. ... On possibility of detection of variable sources using the data of Cold surveys carried out on RATAN-600. ... Detection of Variable Sources Using the Data of "Cold" Surveys. ...

On 1 February 2002 this Mirror was upgraded from NVSSlist v2.10 to NVSSlist v2.17 . ... This form searches the source catalog produced by the NRAO/VLA Sky Survey (NVSS). ... Object name [optional] : . ... Search radius and verification halfwidth in arcseconds [Optional] : . ... Enter a list of positions to search: . ... The contents of the NVSS source catalog and the techniques used by NVSSlist to derive error estimates and other parameters are described here. ...

... LABORATORY OF RADIO ASTRONOMICAL OBSERVATIONS . Radio sources identification is one of the most important tasks of the current radio astrophysics. ... Optical idetification. ... Optical identifications of subsample of steep spectra radio sources from RC catalog using 6m SAO telescope of SAO RAS: optical observations. ... Astronomy Reports. ... Identification of radio sources with data of various radio catalogs allows one to construct continual spectrum of the object and its radio structure. ...

The NICFPS:Dither:Extended Source script allows you to a set of take pairs of dithered source/sky exposures. These pairs of exposures are taken over various points of a small 5-point dither pattern. ... dither point 1 on source . dither point 1 on sky . ... For more information see NICFPS:Dither:Point Source . ... As the script runs the status of each dither point is updated. ... This differs from the NICFPS:Dither:Point Source script, whose dither pattern is aligned with the detector. ...

... All the parameters provided in this database have been obtained using the the MIRIAD ( Sault et al. 1995 ) task MBSPECT . MBSPECT makes a spectrum of the velocity (or frequency) axis of a cube. The spectrum is beam-weighted, over the width specified, for the other image axes. ... Robust parameters are calculated by using an algorithm which minimises the mean absolute deviation of the flux-weighted velocities. mask= This specifies the x-axis ranges to be excluded from any continuum fit. ...

In calculating the NIFS sensitivity, we adopt a read noise of 5 e - , a dark current of 0.01 e - s -1 pix -1 , and a maximum exposure time of 3600 s. Grating . ... e/pix) . ... OH Cont. (e/pix) . ... NIFS should achieve signal-to-noise ratios of ~ 10 per spectral pixel in a 0.1" 0.1" aperture for single 1800 s exposures on uniform, extended, continuum sources with surface brightnesses of J = 15.4, J = 15.0, H = 14.8, and K = 13.5 mag arcsec -2 using the Z , J , H , and K gratings, respectively. ...

First results of X/S and X/Ka-band catalog combinations with full covariance information Andreas Iddink , Christopher Jacobs, Thomas Artz, Axel Nothnagel 22.09.2014 First results of S/X and X/Ka-band catalog combinations with full covariance information Andreas Iddink ­ 22.09.2014 Motivation Features of the ICRF2 ICRF2 (Defining- Sources ) 3414 ... Step: Import of the X/Ka catalog with full covariance information (Data provided by Christopher Jacobs et al. ...

The Texas survey of radio sources covering -35.5{deg} < {delta} < 71.5{deg} at 365MHz . ... We present the Texas Survey of discrete radio sources between -35.5deg and 71.5deg declination (B1950), which was carried out at 365MHz with the Texas Interferometer during 1974-1983. ... The Texas Survey . ... The sources in the simpler model. ... Right Ascension 1950 . ... field separator . ... Some sources came from Version 6 of the Texas Survey ('TS6' in strp field) or Version 7 ('TS7' in strp field) . ...

The Variable Gamma-Ray Source 2CG 135+01 ApJ, 497:L89-L91, 1998 7 h gamma AGN variability . gamma-radio-AGN-variability ADS query . ... Model for the High-Energy Emission from Blazars 1993ApJ.. ... Possible Production of High-Energy Gamma Rays from Proton Acceleration in the Extragalactic Radio Source Markarian 501 astro-ph/9803241 K.Mannheim . ... A theoretical unifying scheme for gamma-ray bright blazars astro-ph/9807317 G. Ghisellini, A. Celotti, G. Fossati, L. Maraschi, A. Comastri . ...

Next: Sample Properties Up: Sample Identification Previous: Comments on Individual Sources . Previously known serendipitous sources were selected by cross-correlating WGACAT with a variety of optical and radio catalogs, including the Ver?n-Cetty & Ver?n (1996) and Hewitt & Burbidge (1993) quasar catalogs, the 1 Jy (Stickel et al. 1994) and S4 (Stickel & K?hr 1994) radio catalogs, and the BL Lac catalog of Padovani & Giommi (1995b). ... Details of these 97 objects are given in Table 6. ...

Family ASTRO Event Leaders can follow the links below to find a number of resources and more background reading to help them with their Astronomy Events and expand their knowledge on the topics covered in our series of Leader Kits for educators. ... Print and Web Resources on the Night Sky . ... If you have questions about Family ASTRO, see our Frequently Asked Questions for Educators and Astronomers page , or our Frequently Asked Questions for Families and Friends page. ...