Emission lines from post-AGB UV radiation

Hi,

I am running some models to test the UV contribution from the post-AGB stars to the emission lines of a galaxy. To test this, I use SSPs at the age of 3Gyrs (also tried for 0.1Gyrs and 5Gyrs). Models have no attenuation. The SSPs have solar metallicity. I test 3 separate instances which all have the same parameter values, except that each time I change the pAGB fraction to be 0, 0.5 and 1. I can see that I get ionizing radiation by turning on post-AGB stars.

The problem is that I get emission line fluxes that are all 0. Shouldn't this UV give emission lines for pAGB = 0.5 and pAGB = 1 ? Am I missing something obvious here?

From this tests I get the following plot:

The srcipt I run is the following:

import fsps
import matplotlib.pyplot as plt
import numpy as np

sp = fsps.StellarPopulation(zcontinuous=1)

sp.params['sfh'] = 0
sp.params['dust1'] = 0.0
sp.params['dust2'] = 0.0
sp.params['add_neb_emission'] = True
sp.params['add_dust_emission'] = True
sp.params['nebemlineinspec'] = True
sp.params['logzsol'] = 0.0
sp.params['gas_logz'] = sp.params['logzsol']

t = 3.0
for p in [0.0,0.5,1.0]:
	sp.params['pagb'] = p
	wave, flux = sp.get_spectrum(tage=t,peraa = True)
	plt.loglog(wave, flux,label='pAGB = ' + str(p))
	plt.xlabel('Wavelength (Angstroms)')
	plt.ylim([1e-7, 1e-2])
	plt.xlim([1e2, 1e5])
	plt.ylabel('Flux')
	plt.title('tage = ' + str(t)+'Gyr')
	plt.legend(fontsize=14)
plt.show()

Best,
Babis

Commencez par exécuter le script Python fourni et examinez l’appel à get_spectrum ainsi que les paramètres pAGB, nebemlineinspec et add_neb_emission. Comparez les spectres obtenus pour les trois valeurs de pAGB ; l’issue est terminée lorsque la cause des flux de raies d’émission nuls a été identifiée et que le comportement attendu ou la configuration requise est documenté.