VERNE

Voigt fitting code to derive Ew and Rv using Normalised spEctra (VERNE)

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CaT version

The current version is tailor made to fit the 3 Calsium triplet lines and derive the Equivalent Width, Radial velocity, [Fe/H], and [Ca/H].

The current version requires:

• lmfit
• specutils
• astropy
• seaborn

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You will need a input file in .txt

Lambda  Flux_spec  Noise 
8000.756  0.9336  1.0660 
8002.006  1.2451  1.0531 

If you don't have the noise, don't worry, at line 395 you will find an your option.

Set up the code

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In the lines between 400 and 490 you will find some set up options as:

• interactive_mode
• Magnitude and Distance
• Bandpass
• RV correction (if necessary)

In the interactive_mode you have 3 options True, False or 'Guess' where 'Guess' is rv based guessing system for when you have some ideia about what is the radial velocity.

Magnitude and Distance are used to devrive [Fe/H] and [Ca/H] applying the Starkenburg et al. 2010 calibrations.

For the bandpass you have 3 options: Rutledge et al. 1997a; Carrera et al. 2007; and Vasquez et al. 2018. You can also create your own.

Run

python3 LMVERNE.py [spectrum.txt]

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