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SED@
Evolutionary Synthesis Models:

Confidence levels (II)
On sampling and Poissonian fluctuations
In collaboration with:
David Valls-Gabaud, Valentina Luridiana and J. Miguel Mas-Hesse
Please, refer any use of this results as:
Cerviño et al. 2002, A&A 381, 51 (http://www.laeff.inta.es/users/mcs/SED)

Hello;



For use it you must multiply the output (except EW or V-K) by the ammount of gas transformed in stars, and you must take into account that:
  1. The models assume a Salpeter IMF slope in the mass range 2 - 120 Mo, so the multiply factor is the ammount of gas transformed in stars in this mass range.
  2. The output has been normalized to The amount of gas transformed in stars since the onset of the burst , Mtot

The sigma2(A) value for a given amount of mass transformed into star for any quantity A (except V-K) is obtained using:

sigma2 = A2 / Neff*(A)

with Neff*(A) = Neff(A) x Mtot

Neff must be always denormalized!!


In the case of V-K, the tabulated value is:

sigma2 x Mtot
so it is needed to divide by Mtot and aply the square root for obtain the sigma value.

See the reference paper for more details and for obtain the corresponding confidence levels (Note: the method used in the article for obtain the confidence levels may fail if Neff < 10!!!).



Justicia, no venganza

Justice, not revenge		 
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Miguel Cerviño 2001