Normalize the target flux

The user is offered to normalize the given spectral distribution by:

1. Flux, $F_{norm}$, (in erg/(cm² s Å) for a point source and erg/(cm² s Å arcsec²) for an extended source) at a given wavelength $\lambda_{set}$:

$$F_\lambda = SED_\lambda \times \frac{F_{norm}(\lambda_{set})}{SED_\lambda(\lambda_{set})}$$

where $SED_\lambda$ – given spectral distribution of the object.

2. Apparent magnitude in V filter [Kazakevich et al., 2014], [Pablo Marcos-Arenal et al., 2009]:

$$F_\lambda = SED_\lambda \times 10^{(-0.4 \ m_V)} \times \frac{\int_\lambda R_{\lambda V} \times SED_{Vega_\lambda} d\lambda}{\int_\lambda R_{\lambda V} \times SED_\lambda d\lambda}$$

(2)

where $SED_\lambda$ – given spectral distribution of the object, $m_V$ – apparent magnitude; $SED_{Vega_\lambda}$ – Vega spectra, $R_{\lambda V}$ – V filter throughput. This normalization is made under the assumption that the apparent magnitude of Vega is zero.

Note: Normalization to magnitudes in other filters will be available in subsequent versions of the Spektr-UF exposure calculator.

3. Do not normalize the spectrum.

This option is suitable when the user specifies their own spectrum or specifies an emission spectral line.