Situation when metallicity (FeH) lower than -2.

[martinmestre]

Hello, thank you very much for your packages. It is very useful.

I would like to know if it is normal that for FeH < -2, the isochrone seems to be truncated respect to the -2 case. I have tested for values like -2.001 and I still obtain a very short isochrone, seems to be only the main sequence. I paste my code:

import ezmist
filters = "UBVRIplus"
age = 12e9
metal = -2.001
age_scale = "linear"
r = ezmist.get_one_isochrone(age=age, FeH=metal, v_div_vcrit=0.0,
                    age_scale=age_scale, output_option="photometry",
                    output=filters, Av_value=0.0)
r_color = r["Gaia_BP_EDR3"]-r["Gaia_RP_EDR3"]

import pylab as plt
plt.scatter(r_color, r['Gaia_G_EDR3'],marker=".")
plt.show()

Thank you very much for your help.

[mfouesneau]

I do know have knowledge of the recent MIST models; it was not the case before. I do not see a short isochrone on my side.

[martinmestre]

Hi @mfouesneau thank you for your fast answer. Here I attach a plot with two isochrones, the blue is for FeH=-2 and the red is for FeH=-2.001. For the latter case you obtain a full isochrone? I used the same code snippet above. Thank you very much for any orientation.