- #1
fab13
- 312
- 6
Hello,
Suppose that all stars in this galaxy were born in a single major-merger burst event about 10 Gyr ago
If the luminosity in the B band (absolute magnitude in B-band is equal to -21.22) is dominated by stars of in the RG branch, with masses ##m \sim 1\,\text{L}_{\odot}## (within ##\sim 10\%##) and average luminosities ##\sim 1000\,\text{L}_{\odot}##.
How can I estimate the total stellar mass of this galaxy using the Schechter relation ?
I think that I have to use the law of Schechter :
##N(L)\ \mathrm {d} L=\phi^{*}\left({\frac{L}{L^{*}}}\right)^{\alpha}\mathrm {e}^{-L/L^{*}}{\frac{\mathrm {d} L}{L^{*}}}##
or maybe Salpeter distribution : ##\text{d}N=0.06\,\times\,M^{-2.35}\,\text{d}M##
But how to introduce the parameters of Red-Giants of ##1\,\text{M}_{\odot}## with ##L=1000\,\text{L}_{\odot}## ?
Initially, I calculate the fraction of masse between ##m_{1}=0.9## and ##m_{2}=1.1\,\text{M}_{\odot}## :
##\text{d}N(m_{1}<m<m_{2})=\int_{m_{1}}^{m_{2}}\,\Phi(m)\,\text{d}m=0.06\,\dfrac{(0.9^{-1.35}-1.1^{-1.35})}{1.35} = 1.22 \%##
Anyone could see the trick to compute total stellar mass from these parameters with above laws ?
Regards
Suppose that all stars in this galaxy were born in a single major-merger burst event about 10 Gyr ago
If the luminosity in the B band (absolute magnitude in B-band is equal to -21.22) is dominated by stars of in the RG branch, with masses ##m \sim 1\,\text{L}_{\odot}## (within ##\sim 10\%##) and average luminosities ##\sim 1000\,\text{L}_{\odot}##.
How can I estimate the total stellar mass of this galaxy using the Schechter relation ?
I think that I have to use the law of Schechter :
##N(L)\ \mathrm {d} L=\phi^{*}\left({\frac{L}{L^{*}}}\right)^{\alpha}\mathrm {e}^{-L/L^{*}}{\frac{\mathrm {d} L}{L^{*}}}##
or maybe Salpeter distribution : ##\text{d}N=0.06\,\times\,M^{-2.35}\,\text{d}M##
But how to introduce the parameters of Red-Giants of ##1\,\text{M}_{\odot}## with ##L=1000\,\text{L}_{\odot}## ?
Initially, I calculate the fraction of masse between ##m_{1}=0.9## and ##m_{2}=1.1\,\text{M}_{\odot}## :
##\text{d}N(m_{1}<m<m_{2})=\int_{m_{1}}^{m_{2}}\,\Phi(m)\,\text{d}m=0.06\,\dfrac{(0.9^{-1.35}-1.1^{-1.35})}{1.35} = 1.22 \%##
Anyone could see the trick to compute total stellar mass from these parameters with above laws ?
Regards
Last edited: