LOFAR 150-MHz observations of the Boötes field: catalogue and source counts

By Wendy L. Williams, R. Weeren, H. Röttgering, P. Best, T. J. Dijkema, F. Gasperin, M. Hardcastle, G. Heald, I. Prandoni, J. Sabater and 25 more. 2016

136 citations recorded by the source corpus.

We present the first wide area (19 deg(2)), deep (a parts per thousand 120-150 mu Jy beam(-1)), high-resolution (5.6 x 7.4 arcsec) LOFAR High Band Antenna image of the Bootes field made at 130-169 MHz. This image is at least an order of magnitude deeper and 3-5 times higher in angular resolution than previously achieved for this field at low frequencies. The observations and data reduction, which includes full direction-dependent calibration, are described here. We present a radio source catalogue containing 6 276 sources detected over an area of 19 deg(2), with a peak flux density threshold of 5 sigma. As the first thorough test of the facet calibration strategy, introduced by van Weeren et al., we investigate the flux and positional accuracy of the catalogue. We present differential source counts that reach an order of magnitude deeper in flux density than previously achieved at these low frequencies, and show flattening at 150-MHz flux densities below 10 mJy associated with the rise of the low flux density star-forming galaxies and radio-quiet AGN.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/c832cc8b08dafb36ae2179cfccc4006a446f73c9

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. M. Hardcastle
2. P. Best
3. D. Frail
4. P. V. D. Werf
5. Matthias Hoeft
6. Michael J. Jarvis
7. R. Weeren
8. J. Oonk

In Nuclear and High Energy Physics

1. M. Haverkorn
2. D. Frail
3. Matthias Hoeft
4. R. Weeren
5. J. Oonk
6. P. Jagannathan
7. P. Best
8. R. Cassano

Citations in the corpus

• The LOFAR Two-metre Sky Survey. I. Survey description and preliminary data release (2016, methodology): “Several approaches are being developed to minimise these direction-dependent effects (e.g. Tasse 2014 and Yatawatta 2015), including the facet calibration procedure (van Weeren et al. 2016a and Williams et al. 2016).”
• The GMRT 150 MHz all-sky radio survey - First alternative data release TGSS ADR1 (2016, background): “Recently, using the LOFAR telescope, source counts at 150 MHz have been extended for the first time down to 1–2 mJy, which is an order of magnitude deeper than previous results (Williams et al. 2016).”