1. 1.4 GHz Source Counts Melanie Gendre Walter Max-Moerbeck
Mitch Mickaliger
Katie Rabidoux
Under the supervision of Brian Mason and Jim Condon

2. Overview
Used GBT to measure continuum emission in a random patch of sky
Calculated source counts
Distribution of sources as function of flux density
Large GBT beam size (9') can cause confusion
Detection of a group of sources as one source

3. Observations Used GBT (L-Band)‏ 1410 MHz Continuum
Mapped 10º x 1º area
9' beam, Nyquist sampled
Bonn 1420 MHz Survey
Reich, 1982, A&AS48, 219.
Reich and Reich, 1986, A&AS63, 205.

4. Parameters Calibration source 3C286 G = 1.69 K/Jy FWHM = 9 arcmin
Effective Area = 4664 m^2
Aperture efficiency = 0.59
antenna solid angle = ^-6 srad
mean beam solid angle = ^-6 srad
mean beam efficiency = 0.55
Tsys = 14.5 K
With an integration time of 0.2 s, and bandwidth of 50 MHz we get
Tnoise = 4.6 mK
Snoise = 2.71 mJy

5. Reduction

6. Results
For a distribution of sources at a given flux density, the number of sources can be described by the power law
n(S) = k * S-γ
where k is a normalization constant and γ is the power law coefficient

7. Results: Source Count {gamma, k}
{{1.7, }, {1.9, }, {2.1, }, {2.3, }}
{S^2.5 n(s)}
{ , , , }