My research



Current research


My current research involves exploring the evolution of disk galaxies at intermediate redshifts (0.4 ≤ z ≤ 1.0). I combine spectroscopic and photometric data from the Cosmic Evolution Survey (COSMOS) with morphological classifications from the Galaxy Zoo project to produce a sample of 2,380 face-on disk galaxies, which can be found here. I also produce a sub-sample of barred disk galaxies, which can be seen here.

These samples are used to explore whether the abundance of bars in disk galaxies is redshift dependent. We find that the bar fraction increases towards lower redshifts, with this evolution being driven by the most massive disk galaxies, while the fraction of bars found in low mass disk galaxies increases at a much slower rate across the 8 Gyrs we explore.

This is currently work in progress, with a paper currently in preparation. Postage stamp images of the galaxies used in this paper can be seen here. You can also find the full decision tree used in Galaxy Zoo: Hubble here.


First and second author publications


Galaxy Zoo: An independent look at the evolution of the bar fraction over the last eight billion years from HST-COSMOS
Thomas Melvin, Karen Masters, Chris Lintott, Robet C. Nichol, Brooke Simmons, et al. Submitted.

Galaxy Zoo: The evolution of bar fraction trends from z≈0.65 to z≈0
Edmond Cheung, Thomas Melvin et al. In prep.

Other publications I am part of


Galaxy Zoo 2: detailed morphological classifications for 304,122 galaxies from the Sloan Digital Sky Survey
Kyle Willett, et al. 2013 MNRAS 435 2835W (arXiv:1308.3496).

Galaxy Zoo: Observing secular evolution through bars
Edmond Cheung, et al. 2013 (arXiv:1310.2941).