I assume you removed the linear before performing the sine fit?
On Fri, Dec 30, 2022, 6:09 PM Dr Gordon MacLeod <g...@hartrao.ac.za> wrote: > Hi Andrew, > > Hope you are enjoying your Christmas break, Merry Christmas! > > I thought I'd share with you an image I've recently created on excited-OH > masers at 6.035 GHz, see attached. This is not yet published nor released > data. > > These are fitted gaussian profiles to a Zeeman pair. You can easily see > the cyclical undulation. > > I fitted a sinusoid to this and found a period of 360.3+/-0.5 Days and NOT > 365 days. It is not yet conclusive; more data is required. > > There are 3 potential possibilities to explain these results. > > 1. The period is 365 days and there is a source about 30-40 arcsec away > from the beamcenter - it's possibly a baricentric/heliocentric vlsr > correction issue. > > 2. It is two Zeeman pairs line-blended and one or both are periodic. > > and > > 3. It is a gravitational effect, the result of masers associated with a > binary - when the YSOs are aligned the velocities closer... > > I cannot find an object at about 30" but maybe it's there. I think it is > option 2 to be honest. > > Of coarse there can be other explanations but they become less and less > likely. > > More to the point, this result demonstrates the sensitivity of monitoring > masers and velocity drift. This is a new line of research worth continuing > and using more observatories. > > Who knows what it will turn up. > > Regardless, thought of our conversation in SA when I first saw it. > > All the best in 2023, Happy New Year! > > gordon > > -- > You received this message because you are subscribed to the Google Groups " > casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/df7fd46e2544a2a9ed42cb2eb33c9a60.squirrel%40mail.hartrao.ac.za > . > -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu. To view this discussion on the web visit https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAG4nf72CKGiyefxSWf-vWHrjtmgh1NELWgTFOYtXRd4Pa5fCTg%40mail.gmail.com.
