Abstract
We have made a quantitative calculation for the systematic evolution of the average extinction by interstellar dust in host galaxies of high-redshift Type Ia supernovae by using a realistic model of photometric and chemical evolution of galaxies and supernova rate histories in various galaxy types. We find that the average B-band extinction [A(B)] at z similar to 0.5 is typically 0.1-0.2 mag larger than the present value, under a natural assumption that dust optical depth is proportional to gas column density and gas metallicity. This systematic evolution causes average reddening with E(B-V) similar to 0.025-0.05 mag with the standard extinction curve, and this is comparable with the observational uncertainty of the reddening of high-redshift supernovae. Therefore, our result does not contradict the observations that show no significant reddening in high-z supernovae. However, the difference in apparent magnitude between an open universe and a Lambda-dominated flat universe is only similar to 0.2 mag at z similar to 0.5, and hence this systematic evolution of extinction should be taken into account in a reliable measurement of cosmological parameters. Considering this uncertainty, we show that it is difficult to discriminate between open and Lambda-dominated flat cosmologies from the current data.
Original language | English |
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Pages (from-to) | L65-L68 |
Number of pages | 4 |
Journal | Astrophysical Journal Letters |
Volume | 526 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Dec 1999 |
Keywords
- cosmology : observations
- dust, extinction
- galaxies : evolution
- supernovae : general
- IA SUPERNOVAE
- GALAXIES
- LUMINOSITY
- MODEL
- MAPS