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This is for a project in astronomy with extensive data analysis. How should I calculate the distance of galaxies using AGN and supernova Ia? I am using the data from dr17 of SDSS.

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  • $\begingroup$ What have you already tried? Type Ia have absolute magnitudes of -19.3, so you probably could use inverse square law given you have magnitude of the Ia in said galaxy. $\endgroup$
    – WarpPrime
    Jan 31, 2022 at 18:19
  • $\begingroup$ @fasterthanlight But who ever has that information? $\endgroup$
    – zephyr
    Jan 31, 2022 at 19:18

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The absolute peak magnitude of type 1a supernovae is to some degree correlated with the decay time of the supernova light curve. The Phillips relationship says that the peak absolute magnitude in the blue (B) region of the spectrum is

$$M=-21.726+2.698\cdot \Delta m$$

where $\Delta m$ is the observed decline of the B-magnitude 15 days after maximum.

With the observed apparent magnitude $m$ you have then the distance modulus $m-M$ and thus the distance $d$

$$d=10^{1+(m-M)/5} \ \mathrm{Parsecs}$$

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