N2227 Scan 272

Contents

Observing log information

  Object:           N2227
  On scan num:      272 274 276 278 280 282 284 286 288 290 292 294
  Off scan num:     273 275 277 279 281 283 285 287 289 291 293 295
  R.A.:             6.432776 hrs
  Dec.:             -22.004229 deg
  On azimuth:       160.397822 deg
  On zenith dist.:  62.845990 deg
  Off azimuth:      160.254834 deg
  Off zenith dist.: 62.883951 deg
  MJD:              52234
  UTC:              0.268380
  Center freq.:     1409.901999 MHz
  Doppler:          0.00004481
  Num. correlators: 2
  Spectrom. atten.: 34 40 dB
  Bandwidth:         5.0 MHz
  Num. channels:    1024
  Eff. integration: 3600 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:      0.069 Jy
  Lower 20% velocity: 2118.4 km/s
  Upper 20% velocity: 2399.8 km/s
   Systemic velocity: 2259.1 km/s
   Line width (20%):   281.4 km/s
  Profile integral:   12.83 Jy * km/s
                 A:   10.29
                 B:   12.60
         Ratio B/A:   1.224
  Flux integral
     velocity range:  2091.1 - 2424.8 km/s

Comments