Object: DDO_221 On scan num: 972 Off scan num: 973 R.A.: 0.032731 hrs Dec.: -15.464151 deg On azimuth: 221.872969 deg On zenith dist.: 64.924591 deg Off azimuth: 221.835446 deg Off zenith dist.: 64.902596 deg MJD: 52532 UTC: 0.345856 Center freq.: 1419.460104 MHz Doppler: 0.00000088 Num. correlators: 2 Spectrom. atten.: 35 39 dB Bandwidth: 5.0 MHz Num. channels: 1024 Eff. integration: 300 seconds
This spectrum is the integration of all data for the scan with spectra from both polarizations added together. The spectral intensities are Ssys * (on - off) / off, where Ssys is the system temperature in Jy. The system noise flux density equivalent is calibrated for each scan with a calibration noise source firing during each scan. The cal value, in Jy, is calibrated by comparison with a number of continuum sources as described in the summary web page
This is the section of spectrum measured to obtain the parameters listed below. The three horizontal dotted lines are the baseline, the peak level selected, and 20% of the peak level. The two vertical dotted lines mark the selected 20% line width edges. The solid horizontal line marks the velocity range chosen for the the line profile flux density integral. This spectrum has a second-order least squares fit baseline removed using most of the baseline shown in Figure 1.
Peak intensity: 4.850 Jy Lower 20% velocity: -155.8 km/s Upper 20% velocity: -91.0 km/s Systemic velocity: -123.4 km/s Line width (20%): 64.8 km/s Profile integral: 205.26 Jy * km/s A: 187.53 B: 207.86 Ratio B/A: 1.108 Flux integral velocity range: -206.0 - -61.9 km/s