From: <adeller_at_email.protected>
Date: Wed, 31 Aug 2005 14:32:47 +1000 (EST)

Hi guys,

I don't believe that the fringe we saw could be associated with the maser,
since we were correlating 16 MHz of bandwidth, and the maser feature is
very narrow, hence it appears as a spike in the frequency domain. This
spike in the frequency domain manifests as a sinusoid in the lag domain,
and since the fringe finder looks for a spike in the lag domain there is
no way we could see anything. The fringe can only be due to emission
which extends across the band, which must be the continuum HII emission.

Cheers,
Adam

On Wed, 31 Aug 2005, Sergei Gulyaev wrote:

>Hi Chris,
>
>4 Jy! Then it could be the maser itself! But how did you get 1.4%? I
>may miss something, or my approach was too simplistic. I just took the
>ratio of the line width to the bandwidth and got < 0.1%.
>
>Cheers,
>Sergei
>
>>>>>>> Chris Phillips <Chris.Phillips_at_csiro.<!--nospam-->au> 31/08/2005 3:39:39 p.m.
>>>>>>>
>Sergei,
>
>An OH maser is typically about 3 kHz (0.5 km/s). So your sensitivity
>is
>down by 1.4%, ie a 300 Jy maser is equivalent to a 4 Jy continuum
>source -
>if you correlate with 5000 spectral channels.
>
>Cheers
>Chris
>

!=============================================================!
Adam Deller Ph +61 3 9214 8502
SKA Group Fax +61 3 9214 8797
Centre for Astrophysics and Supercomputing
Swinburne University, Hawthorn VIC 3123
!=============================================================!
Received on 2005-08-31 14:33:20