The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra

Details The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra

2009-04-13

arxiv.org/abs/0904.2011v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

13 pages, 8 tables, 7 figures, full electronic tables at http://www.aoc.nrao.edu/~fowen/papers/SWIRE/90cmpaper2/, accepted AJ

Scientific paper

10.1088/0004-6256/137/6/4846

We present one of the deepest radio continuum surveys to date at a wavelength ~1 meter, at 324.5 MHz. The data reduction and analysis are described and an electronic catalog of the sources detected above 5 sigma is presented. We also discuss the observed angular size distribution for the sample. Using our deeper 20cm survey of the same field, we calculate spectral indices for sources detected in both surveys. The spectral indices for 90cm-selected sources, defined as S ~nu^(-alpha}, shows a peak near 0.7 and only a few sources with very steep spectra. Thus no large population of very steep spectrum microJy sources seems to exist down to the limit of our survey. For 20cm-selected sources, we find similar mean spectral indices for sources with S_20>1 mJy. For weaker sources, below the detection limit for individual sources at 90cm, we use stacking to study the radio spectra. We find that the spectral indices of small (<3") 20cm-selected sources with S_20< 10 mJy have mean and median alpha(90,20)~0.3-0.5. This is flatter than the spectral indices of the stronger source population. We report log N-log S counts at 90cm which show a flattening below 5 mJy. Given the median redshift of the population, z~1, the spectral flattening and the flattening of the log N-log S counts occurs at radio luminosities normally associated with AGN rather than with galaxies dominated by star-formation.

Affiliated with

Also associated with

No associations

Rating

The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Deep SWIRE Field II. 90cm Continuum Observations and 20cm-90cm Spectra will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-97903