NGC985 Scan 3216

Contents

Observing log information

  Object:           NGC985
  On scan num:      3216 3218 3220 3222 3224 3226 3228 3230 3232 3234 3236 3238 3240 3242 3244 3246 3248 3250 3252 3254 3256
  Off scan num:     3217 3219 3221 3223 3225 3227 3229 3231 3233 3235 3237 3239 3241 3243 3245 3247 3249 3251 3253 3255 3257
  R.A.:             2.577058 hrs
  Dec.:             -8.785505 deg
  On azimuth:       200.206019 deg
  On zenith dist.:  49.237146 deg
  Off azimuth:      200.174157 deg
  Off zenith dist.: 49.230373 deg
  MJD:              52277
  UTC:              0.085428
  Center freq.:     1362.773706 MHz
  Doppler:          -0.00008742
  Num. correlators: 2
  Spectrom. atten.: 34 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 6300 seconds

Raw spectrum

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

Figure 1. Unedited spectrum

Measured spectrum

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.

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.006 Jy
  Lower 20% velocity: 12593.6 km/s
  Upper 20% velocity: 13134.8 km/s
   Systemic velocity: 12864.2 km/s
   Line width (20%):   541.3 km/s
  Profile integral:    1.68 Jy * km/s
                 A:    1.50
                 B:    1.86
         Ratio B/A:   1.238
  Flux integral
     velocity range:  12508.9 - 13210.7 km/s

Comments

extremely low SNR, edge locations are strictly guesses