Object: NGC7771 On scan num: 171 173 175 177 179 181 Off scan num: 172 174 176 178 180 182 R.A.: 23.856900 hrs Dec.: 20.111727 deg On azimuth: 265.560854 deg On zenith dist.: 50.929469 deg Off azimuth: 265.529915 deg Off zenith dist.: 50.893567 deg MJD: 52421 UTC: 0.688021 Center freq.: 1400.536680 MHz Doppler: 0.00007862 Num. correlators: 2 Spectrom. atten.: 35 42 dB Bandwidth: 10.0 MHz Num. channels: 1024 Eff. integration: 1800 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: 0.040 Jy Lower 20% velocity: 4004.0 km/s Upper 20% velocity: 4575.0 km/s Systemic velocity: 4289.5 km/s Line width (20%): 571.0 km/s Profile integral: 17.70 Jy * km/s A: 20.26 B: 19.87 Ratio B/A: 0.981 Flux integral velocity range: 3918.8 - 4682.1 km/s
very poor baseline, flux integral very inaccurate