Observing parameters
Standard settings (until summer 1996):
- Frequency of the 21-cm line (rest frequency = 1420.40575 MHz)
- 14 telescopes, 40 interferometers (2 redundant)
- Spectral line backend (DXB)
- Baselines (min.-max.-increment): 36 (54, 72)m - 2700 (2718, 2736)m - 72m
- Polarization: xx and yy
- Optical velocity definition: freq = freq0 * 1/(1 + vel/c), where freq
= frequency; freq0 = rest frequency; vel = velocity and c =speed of light
- Uniform velocity taper (velocity resolution = 1.2 * channel spacing)
The other settings depend on the width of the global profile (W20) of the
galaxy (taken from the RC3). Below a table with other observing
parameters have been listed.
W20 Number of Channel Number of Bandwidth S NH
(km/s) channels spacing bits (MHz) (mJy/beam) (atoms/cm2)
>300 64 16.4 1 5 1.5 1.2 1020
100<>300 128 4.1 1 2.5 3.0 6.1 1019
<100 128 2.1 2 1.25 4.0 4.0 1019
S = approximate value for the r.m.s. noise at full resolution, and NH =
approximate value for the column density per channel.
For more information about the
observational settings, click
here (choose your favorite galaxy and click on the notes for
observations and reduction).
As the 12 hours observations, but since HI information was not
available, the bandwidth and the number of channels are based on the
optical inclination given in the RC3.
