Nan value while estimating total elemental abundance using ICF "DIMS14"

[Avijit Mandal]

Hello everyone,

I am trying to estimate the total elemental abundances using ICF Family 'DIMS14.

If only 'He1' and 'He2' are detected but not 'He3, then according to the formula of the ICF  'DIMS14_12', the value of the ICF should be 1 and the total elemental abundance of 'O' should be the sum of the ionic abundances of 'O2' and 'O3'. But when I do this, it is giving Nan.

Am I missing something here?

Thanks in advance.

Regards,

Avijit Mandal

[Jorge García Rojas]

Hi Avijit,

if you are not detecting HeII lines, then it has no sense to use ICF DIMS14_12 because He++ abundances are undefined. Indeed, as you correctly point out, there is no need of using any ICF

cheers,

Jorge

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[Avijit Mandal]

Thank you for the reply. 

For checking, I added some He++ abundance. But again it is giving nan value for O and If I try to calculate it for N using 'DIMS14_14', it gives a warning that ICF cannot be evaluated.

I am using the following script.

abun_dic_test = {'He1r':0.1,'He2r': 0.07,'He3r':0.0005,'O2':1.62e-05,'O3':0.00028,'N2':1.15e-06}
elem_abun = icf.getElemAbundance(abun_dic_test,icf_list='DIMS14_14')
for icf_key in elem_abun:
    print(f'{icf_key}: {np.log10(elem_abun[icf_key])+12}')
Thanks and regards,

Avijit Mandal

[Jorge García Rojas]

Hi again,

well, the problem is that ice.getElemAbundance do not recognize the labels He1r, He2r and He3r. First, you have to take into account that He has only two ionization stages: He+ and He++ so I do not exactly know what you mean with He3r. On the other hand, the nomenclature adopted for the ionic abundances from He recombination lines in the ICF scheme is similar to that adopted for the ionic abundances for collisional excited lines, so He2 would be the He+ abundance and He3 would be the He++ abundance.

So if you try now the following

abun_dic_test = {'He2':0.1,'He3': 0.07,'O2':1.62e-05,'O3':0.00028,'N2':1.15e-06}
elem_abun = icf.getElemAbundance(abun_dic_test,icf_list=‘DIMS14_12’)

it should work

On the other hand, if you try

elem_abun = icf.getElemAbundance(abun_dic_test,icf_list=‘DIMS14_14’)

i won’t work because you need first to add the resulting elem_abun(‘DIMS14_12’) to your dictionary

Hope it helps

Jorge