Foreground: LWA1

LWA1 Radio Maps

Coordinate System:
Equatorial
Projection Type:
2.0° to 4.7°
Resolution:
HEALPix, ring, res 8 (Nside=256)
Original Data Source:
LWA1 Low Frequency Sky Survey
Download Links:
fg_lwa1_radio_maps_get.html

This is a survey of the radio sky done using the first station of the Long Wavelength Array at nine frequencies between 35 and 80 MHz with spatial resolutions ranging from 4.7° to 2.0°, respectively. The maps cover the sky north of a declination of -40°. A conservative estimate of the calibration accuracy of these maps is in the 15–25 per cent range, in terms of both the resolved structure and the sky-averaged temperature.


Survey Parameters
Frequency
(MHz)		 Centre frequency
(MHz)		 Bandwidth
(kHz)		 Beam sizea
(degrees)		 Confusion
noiseb (Jy beam−1)		 Thermal
noisec (Jy beam−1)
35 34.979 957 4.8 × 4.5 163 38
38 38.042 957 4.5 × 4.1 130 31
40 40.052 957 4.3 × 3.9 114 27
45 44.933 957 3.8 × 3.5 82 20
50 50.005 957 3.4 × 3.1 62 16
60 59.985 957 2.8 × 2.6 38 10
70 70.007 957 2.4 × 2.2 25 7
74 73.931 957 2.3 × 2.1 22 6
80 79.960 957 2.1 × 2.0 18 5

Notes.aAssuming natural weighting.

bCalculated from source counts at 1.49 GHz (Condon 1974; Mitchell & Condon 1985) and scaled to these frequencies using a spectral index of −0.7 (Lane et al. 2014).

cCalculated assuming a 61-ms integration time and a sky temperature of 2000 K at 74 MHz with a spectral index of −2.5.

More details can be found in:

"The LWA1 Low Frequency Sky Survey", Dowell, J., et al. 2017, MNRAS, 469, 4537, ADS

The LWA1 Low Frequency Sky Survey