Galaxy Zoo Talk

Color of galaxies

  • Nyctophilia by Nyctophilia

    Can the color of galaxies determine their rough age?

    Posted

  • Padme-1 by Padme-1

    I would like to know also.Good question.I hope we get a comment.

    Posted

  • c_cld by c_cld

    THE DEEP2 GALAXY REDSHIFT SURVEY: EVOLUTION OF THE COLOR–DENSITY RELATION AT
    0.4 < z < 1.35

    ABSTRACT Using a sample of 19,464 galaxies drawn from the DEEP2 Galaxy Redshift Survey, we study the relationship between galaxy color and environment at 0.4 < z < 1.35. We find that the fraction of galaxies on the red sequence depends strongly on local environment out to z > 1, being larger in regions of greater galaxy density. At all epochs probed, we also find a small population of red, morphologically early–type galaxies residing in regions of low measured overdensity. The observed correlations between the red fraction and local overdensity are highly significant, with the trend at z > 1 detected at a greater than 5 level. Over the entire redshift regime studied, we find that the color–density relation evolves continuously, with red galaxies more strongly favoring overdense regions at low z relative to their red–sequence counterparts at high redshift.

    So an answer to your question would be 'Yes there is a correlation between color and redshift (age) provided the knowledge of environment density'.
    In GZ4 small thumbnails pics without an eyeball on density it's difficult to infer the 'photometric' redshift on the only clue of color which was processed by unknown pipelines from different filters in different (Goods/Cosmos/EGS...) fields. Moreover we don't know the pixscale of images, zoomed differently on target size.
    In short by what we look at, I think we are only enabling to tell something on the morphology!

    Posted

  • Padme-1 by Padme-1

    Thank you for breaking that down for us.Very interesting.

    Posted