N5157 Scan 172

Contents

Observing log information

  Object:           N5157
  On scan num:      172 174 176 178 180 182 184 188 190 192 194 196 198 200 204 206 208 210 212 214 1 3 5 7 9 11 13 15 17 19 348 350 352 354 356
  Off scan num:     173 175 177 179 181 183 185 189 191 193 195 197 199 201 205 207 209 211 213 215 2 4 6 8 10 12 14 16 18 20 349 351 353 355 357
  R.A.:             13.454700 hrs
  Dec.:             32.030323 deg
  On azimuth:       266.554021 deg
  On zenith dist.:  27.368559 deg
  Off azimuth:      266.521313 deg
  Off zenith dist.: 27.332564 deg
  MJD:              52769
  UTC:              0.239722
  Center freq.:     1386.788132 MHz
  Doppler:          -0.00005337
  Num. correlators: 2
  Spectrom. atten.: 0 0 dB
  Bandwidth:        12.5 MHz
  Num. channels:    8192
  Eff. integration: 10068 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:      0.010 Jy
  Lower 20% velocity: 7049.3 km/s
  Upper 20% velocity: 7592.8 km/s
   Systemic velocity: 7321.0 km/s
   Line width (20%):   543.5 km/s
  Profile integral:    3.12 Jy * km/s
                 A:    3.04
                 B:    3.20
         Ratio B/A:   1.052
  Flux integral
     velocity range:  7031.1 - 7658.5 km/s

Comments

Scans 172 - 214, 1 - 19, and 348 - 356 with spectral bins averaged to 2.7 km/s resolution.