A Multiwavelength Study of HUDF Tadpole Galaxies
Abstract
Multiwavelength data are essential in order to provide a complete picture of galaxy evolution and to inform studies of galaxies’ morphological properties across cosmic time. Here we present results of a multiwavelength investigation of the morphologies of “tadpole” galaxies at intermediate redshift in the Hubble Ultra Deep Field. These galaxies were previously selected from deep Hubble Space Telescope (HST) F775W data based on their distinct asymmetric knot-plus-tail morphologies (Straughn et al. 2006). Here we use deep Wide Field Camera 3 (WFC3) near-infrared imaging in addition to the HST optical data in order to study the rest-frame UV/optical morphologies of these galaxies across the redshift range 0.3<z<3.2. This study reveals that the majority of these galaxies do keep their general asymmetric morphology in the rest-frame UV/optical over this redshift range, if not the distinct “tadpole” shape. Resolution effects play a role in this, more so than genuine morphology changes across wavelength. The average stellar mass of tadpole galaxies is lower than field galaxies, with the effect being slightly greater at higher redshift. The average age of tadpole galaxies is slightly younger than field galaxies, and the average star formation rate for tadpoles is higher than field galaxies. These average effects combined support the conclusion that this subset of galaxies are in an active phase of assembly, either late-stage merging or as a result of internal disk instability
- Publication:
-
IAU General Assembly
- Pub Date:
- August 2015
- Bibcode:
- 2015IAUGA..2258114S