measurements of emission lines with different IRAF version
Mao yewei wrote on Mar 30, 2008
Dear everyone,
I measured the same spectral emission line by SPLOT with different IRAF versions (2.12 and 2.14), and found there are a little differences of flux between them. While the case of EQW is even terrible (large differences). I've no idea about these differences. So I'm not sure which one is more reliable (or both are OK). Is there any kind one who can help me or tell me the differences between the two versions?
Thanks in advance!
Bests,
Owen
I measured the same spectral emission line by SPLOT with different IRAF versions (2.12 and 2.14), and found there are a little differences of flux between them. While the case of EQW is even terrible (large differences). I've no idea about these differences. So I'm not sure which one is more reliable (or both are OK). Is there any kind one who can help me or tell me the differences between the two versions?
Thanks in advance!
Bests,
Owen
Francisco Valdes wrote on Mar 30, 2008
Hi Owen,
In general the more recent version would be the one most likely to be correct since any identified bugs would have been fixed. It is rare that change would actually make things worse.
However, SPLOT has evolved very little in quite some time (I don't think there have been any changes between the versions you mention). To say anything specific would require knowing exactly what you did (there are several ways to measure lines in SPLOT and some depend, sometimes sensitively, on cursor input).
Let me know if I can shed any more light on your problem.
Yours,
Frank Valdes
In general the more recent version would be the one most likely to be correct since any identified bugs would have been fixed. It is rare that change would actually make things worse.
However, SPLOT has evolved very little in quite some time (I don't think there have been any changes between the versions you mention). To say anything specific would require knowing exactly what you did (there are several ways to measure lines in SPLOT and some depend, sometimes sensitively, on cursor input).
Let me know if I can shed any more light on your problem.
Yours,
Frank Valdes
Mao yewei wrote on Mar 30, 2008
Thank you very much, Frank. I use k-key to measure lines and find that it does depend on the marked position at continuum sensitively. You are right!
Last post on Mar 30, 2008