Monday, July 20, 2020

Peak-Gap-Peak feature presentation for Exo3 conference

I am presenting the Peak-Gap-Peak feature to the Exo3 Conference.

I place some supporting links here, highlighted by linking my explanation of "How to See These Features Yourself":



1. How to obtain a histogram showing the gap in period space, as shown in Taylor 2019:
Go to http://exoplanets.org/plots and choose "Advanced" and "Histogram Plot". 
Enter "Per" into the data field to to histogram the period (per), 
Click log scale to bin by log period.
Click "Add Filter" upon which to do the binning.
Then enter this filter into the "Filter" field (it does not matter if you name the filter):
MSINI[mjupiter] > 0.0 && FE > 0.00 && PER[day] > 1 && PER[day] < 5001 && STARDISCMETH = 'RV' && TEFF[k] > 4500 && TEFF[k] < 6500 && LOGG > 4.00 && !BINARY && ECC < 01.20 && DATE < 2016
Then click "Configure Histogram" to adjust the size and placement of the bins:
Choose Logarithmic Bins
Enter the Bin Factor: 1.169576076
Enter the “Min”imum to be 0.938
Enter a max of 5e+3
These were to get boundaries of four bins to fall at the period of 923.8 and 493.7 days.
The “deep” (zero objects) part of the gap goes down to 653.22 days, which is 0.55 of the gap in log period, or a little more than the two longer period bins.
From 653.22 days to the boundary of the short period pileup at 493.7 days, there are six objects in what we call the “shallow” gap.
Then the double-peak separated by a gap from Figure 1 of Taylor 2019 pops right out!

If you choose to see the histogram binned on the equilibrium temperature based on multiplying the semi-major axis “A” with the dependence on stellar mass of M^(-0.5), then replace using the period in the X-axis with
A*MSTAR^(-0.5)


2. How to view the scatter plot that shows the gap shifting in semi-major axis with stellar mass, with a slope in log space of -1/2
Choose “Advanced” and “Scatter Plot”
Click "Add Filter"
Then enter this filter into the "Filter" field:
MSTAR[msun] < 1.29 && MSTAR[msun] > 0.7 && PER[day] > 0 && A[au] > 0.0 && A < 3.5 && MSINI[mjupiter] > 0.0 && NCOMP >= 1 && FE >= 0.00 && STARDISCMETH = 'RV' && TEFF[k] > 4500 && TEFF[k] < 10500 && LOGG > 0.20 && (!BINARY || STAR = 'HD 34445') && ECC < 01.20 && DATE < 2019
The choice of Mstar and A are made to focus in on the gap.
To see how the gap ends with objects having Mstar of 1.29 Msun in the gap, choose Mstar < 2.3
To see the lines as straight, (with a slope of -½ in logarithmic space), choose a minimum A above zero (i.e. A>0.1), and then you can choose logarithmic bins.
Note that for one planet of HD 34445 the star is incorrectly labeled as a binary star, so the planets of this star are included regardless.


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