|
Description
This table contains a catalog based on deep multifrequency observations made using the Giant Metrewave Radio Telescope (GMRT) at 153, 244, 610 and 1260 MHz of a field centred on J0916+6348, to search for evidence of fossil radio lobes which could be due to an earlier cycle of episodic activity of the parent galaxy, as well as haloes and relics in clusters of galaxies. The authors do not find any unambiguous evidence of episodic activity in a list of 374 sources, suggesting that such activity is rare even in relatively deep low-frequency observations. The authors examine the spectra of all the sources by combining their observations with those from the Westerbork Northern Sky Survey (WENSS), NRAO (National Radio Astronomy Observatories) VLA (Very Large Array) Sky Survey (NVSS) and the Faint Images of the Radio Sky at Twenty-Centimeters Survey (FIRST). Considering only those which have measurements at a minimum of 3 different frequencies, they find that almost all sources are consistent with a straight spectrum with a median spectral index alpha ~ 0.8 (S<sub>nu</sub> ~ nu<sup>-alpha</sup>) which appears steeper than theoretical expectations of the injection spectral index. The authors identify 14 very-steep-spectrum sources with alpha >~ 1.3. This table contains the list of 317 sources (out of the 374 sources which were within 1.5 degrees of the phase center at 153 MHz and had peak brightnesses at least 6 times larger than the local rms value) which were detected at a minimum of 3 frequencies out of the 6 frequencies (153, 244, 327, 610, 1260 and 1400 MHz) which were utilized in this study. The new observations were made on 2005 December 12 at 153 MHz, 2005 November 26 at 244 MHz and 610 MHz, and on 2008 April 22 at 1260 MHz, on the Giant Metrewave Radio Telescope (Pune, India). This table was created by the HEASARC in March 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/392/1403">CDS Catalog J/MNRAS/392/1403</a> file table2.dat. This is a service provided by NASA HEASARC .
|
