about uvamp

[hzhangshao2011]

Hi, Jamie,
In your tutorial about the miriad data reduction, you mentioned that we can use 'uvamp ' to check whether a source is really a point source or not. But how to judge from the results, like the following three figures? What does the dashed line mean?

Thanks!
Hui

[ste616]

Hi Hui,

A point source will have an amplitude that does not vary with the uv-distance. If a source is resolved, then the amplitude will decrease with increasing uv-distance, while if there are one or more confusing sources in the field, the amplitude will vary depending on the distance between the sources and their relative fluxes.

In the plots that you included, it looks more like there are some confusing sources in the field. The dashed line in each plot is the amount of flux that might be expected in each uv-distance bin if it contained only noise.

I hope this helps!

[hzhangshao2011]

Hi, Jamie,

Thank you very much! The result is from a soft X-ray transient source which was usually thought to be a point source (sometimes we can also see the extended structures from the jet). My result is strange and I should check it carefully.

Thanks and best regards,
Hui