Object: NGC4948 On scan num: 1 7 57 59 61 63 65 67 69 71 Off scan num: 2 8 58 60 62 64 66 68 70 72 R.A.: 13.082138 hrs Dec.: -7.946560 deg On azimuth: 118.770498 deg On zenith dist.: 69.623092 deg Off azimuth: 118.788862 deg Off zenith dist.: 69.606471 deg MJD: 52806 UTC: 0.874028 Center freq.: 1414.382099 MHz Doppler: -0.00008897 Num. correlators: 2 Spectrom. atten.: 0 0 dB Bandwidth: 12.5 MHz Num. channels: 8192 Eff. integration: 2940 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 spectrum is the same as Figure 1 but with 4 60-second sub-integrations manually deleted because of interference or a bad baseline.
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 third-order least squares fit baseline removed using most of the baseline shown in Figure 2.
Peak intensity: 0.031 Jy Lower 20% velocity: 1265.2 km/s Upper 20% velocity: 1435.9 km/s Systemic velocity: 1350.5 km/s Line width (20%): 170.7 km/s Profile integral: 4.45 Jy * km/s A: 4.00 B: 4.90 Ratio B/A: 1.224 Flux integral velocity range: 1244.9 - 1450.3 km/s