A2127/A2228: xband Oxygen (O2) from quasar at z=6.3

• a2127:
• There are 4 bands of 100 Mhz .
•  Each band has 4096 channels (24 Khz resolution or .9km/sec).
• a2228: covers 8000 Mhz to about 9300 Mhz.
  
• Each scan has  8 100 Mhz band separated by 85 Mhz .
  
• One band is centered around 8340 Mhz, the second setup is centered near 8980 Mhz.
  

1. do on, off processing for each 5 minute on, off scaling the kelvins using the cals. The input data has been hanning smoothed.
2. Remove a baseline using a 1st order polynomial and a 5th order harmonic.
3. Smooth each on,off pair to 20 channels (18 km/sec).
4. When averaging spectra weight them by 1./Tsys^2.

Data was taken on:

14feb06  (top)

• Fig 1: average the 10 on,off pairs and the two polarization's. The blue dashed lines are the expected locations of the lines. The dashed purple lines assume that 8080 is a valid line.
• Fig 2: This plots the spectra before averaging the two polarization's. Black is polA and red is polB.
• Fig 3-4: The individual on/off pairs (one 100 Mhz band at a time). Black is polA, red is polB. An offset has been applied for plotting. The first scan is at the bottom.

08mar06  (top)

The plots show the individual and averaged spectra (.ps) (.pdf):

• Fig 1: average the 9 good on,off pair. Pol A is blank and polB is red. The dashed blue line assumes that 8082 is a valid line (from the 14feb06 measurment).
• Fig 2: This has the two polarizations averaged.
• Fig 3-4: The individual on/off pairs (one 100 Mhz band at a time). Black is polA, red is polB. An offset has been applied for plotting. The first scan is at the bottom. The sixth on/off pair is included to show what it looked like.

03apr06  (top)

• Fig 1: average the 8 on,off pair. Pol A is blank and polB is red. The dashed blue line assumes that 8082 is a valid line (from the 14feb06 measurment).
• Fig 2: This has the two polarizations averaged.
• Fig 3-4: The individual on/off pairs (one 100 Mhz band at a time). Black is polA, red is polB. An offset has been applied for plotting. The first scan is at the bottom.

may08 (data thru 16may08)  (top)

• 5 min on off position switching with 1 second dumps were taken
• 8 100 Mhz bands were taken during each on/off. Two 680 Mhz bands were measured: 8000 to 8600 Mhz (space by 85 Mhz)  and 8 100 Mhz bands 8600 to 9500 Mhz. After the first day we alternated between these two band.
• the cals were used to convert the on/off -1 to Kelvins (the value at the center of the band was used for the entire band so there will be a little slope in each 100 band).
• A 5 order harmonic and linear polynomial was removed from each 5 minute on/off-1 before averaging.
  
• The data has been smoothed to 21 channels (.5 Mhz).
•  The data was taken 18:30 to 20:00 AST each day. The first 6 days were clear. The 15th had clouds.
  
• The tiedown tracking was disabled after the 3rd? day.

• top: average of all on/off pairs for this freq and then average the pols.
• middle: average of all on/off pairs for this freq but polA (black) polB (red) plotted separately.
• bottom: Individual on/off pairs plotted with offsets for display.
  

• Avg on/off-1 for 8000-8600 data (.ps) (.pdf)
• Avg on/off-1 for 8600-9300 data (.ps) (.pdf)

• Page 1 top: Tsys vs za. Each day is plotted in a different color.
• Page 1 bottom: Tsys vs frequency:
• Page 2,3,4 . The (rms across frequency)/Tsys is plotted for 1,2,3.. up to n accumulated on/off pairs in a log log plot.
• blackis polA, red is polB
• The * are the data points. The line is a linear fit to the data.
• The slope of the line is also printed. Ideally it should be -.5

• The top plot is polA, the bottom plot is polB. I scaled the data to Jy by multiplying by an sefd of 5 Jy for all data.
  
• Black is on source, red is the off source (over the same part of the dish). These should lie on top of each other since the source had no continuum.
  
• At each za there are 8 ons and 8 offs corresponding to the 8 freq bands for an onoff.
• The days were clear except for
  
• 080515 which had a light drizzle before observing and then clouds.  The ground was dry during observing but you couldn't see any stars.
• 080516 cloudy but no rain.
  

• The top plot is polA, the bottom plot is polB.
• The different colors at each za set is a different 100 Mhz frequency band.
• The vertical scale is not the same for all of the days.
• 09may08 - 12may08  +/- .1 Jy
• 13may08 - 14may08  +/- .2 Jy
• 15may08                    +/- .5 Jy (clouds).
  

Summary:

• There is a residual 15 Mhz residual from the 5th order harmonic 5 (20 Mhz).
• After removing the spectral baseline, the rms integrates down as the sqrt(integration time) up to the 140 minutes of on source.
• The total power bounces around at 10 to 20 millijy on clear days and up to 400 milliJy on cloudy days.
• Need to look a little harder for the O2.
  

Misc.   (top)

 

Rest/Topo freq for Z=6.295

restFreq Ghz	TopFreq Mhz
58.324	7995.3
58.447	8012.2
59.591	8169.0
60.306	8267.0
60.434	8284.5