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Description
The authors obtained deep, high-resolution radio interferometric observations at 153 MHz to complement the extensively studied NOAO Bootes field. In their paper, they provide a description of the observations, data reduction and source catalog construction. From their single-pointing GMRT observation of ~12 hours, they obtained a high-resolution (26" x 22") image of ~11.3 square degrees, fully covering the Bootes field region and beyond. The image has a central noise level of ~1.0 mJy beam<sup>-1</sup>, which rises to 2.0 - 2.5 mJy beam<sup>-1</sup> at the field edge, placing it amongst the deepest ~150 MHz surveys to date. The catalog of 598 extracted sources is estimated to be ~92% complete for > 10 mJy sources, while the estimated contamination by false detections is < 1%. The low rms positional uncertainty of 1.24" facilitates accurate matching against catalogs at optical, infrared and other wavelengths. Differential source counts were determined down to < ~10 mJy. The authors find no evidence for flattening of the counts towards lower flux densities as observed in deep radio surveys at higher frequencies, suggesting that their catalog is dominated by the classical radio-loud AGN population that explains the counts at higher flux densities. Combination with available deep 1.4 GHz observations yields an accurate determination of spectral indices for 417 sources down to the lowest 153 MHz flux densities, of which 16 have ultra-steep spectra with spectral indices below -1.3. The authors confirm that flattening of the median spectral index towards low flux densities also occurs at this frequency. The detection fraction of the radio sources in the NIR K<sub>s</sub>-band is found to drop with radio spectral index, which is in agreement with the known correlation between spectral index and redshift for brighter radio sources. This table contains the list of 598 153-MHz sources detected in the GMRT observation and their properties at this frequency. There are a number of other tables of objects in the Bootes field made at other frequencies: <pre> HEASARC Table | Title | Reference BOOTESDF | 1.4GHz imaging of the Bootes field | de Vries+ 2002,AJ,123,1784 LALABOOCXO | LALA Bootes field X-ray source catalog | Wang+ 2004,AJ,127,213 --- | Faint radio sources in NOAO Bootes field | Wrobel+ 2005,AJ,130,923 --- | 16um sources in the NOAO Bootes field | Kasliwal+ 2005,ApJ,634,L1 XBOOTES | X-ray survey of the NDWFS Bootes field | Kenter+ 2005,ApJS,161,9 XBOOTESOID | Optical counterparts in the NDWFS Bootes | Brand+ 2006,ApJ,64,140 | field | </pre> This table was created by the HEASARC in December 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/535/A38">CDS Catalog J/A+A/535/A38</a> file table3.dat. This is a service provided by NASA HEASARC .
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