File:MACSJ0416 (14658926697).png

English: Update 2014 Oct 08: I feel like I am missing something with this image. Compared with ESA's version of this image, which I didn't see until after I'd done this, mine is significantly darker. I thought I had pushed the dimmer details as far as I could. Clearly, that is not the case...

When I realized all of the ACS/WFC data for MACSJ0416 were done, of course I had to process it too. I have used a very similar processing technique for this one as I did with Abell 2744 and yet the massive elliptical galaxies seem much more yellow. I have a very hard time understanding how astronomers accurately measure the colors of galaxies because it's not something I've had any education on and it's probably one of those things you need discipline for rather than a chair and Google but even without that knowledge I can reasonably determine it really does appear more yellow.

This minimal effort involved checking the z of Abell 2744 (z=0.308) and MACSJ0416 (z=0.397). With MACSJ0416 at a higher z / redshift, it makes sense that it looks yellower (or redder, depending on how you think). I'm not totally convinced that the difference isn't also caused by a difference in exposure time for the individual channels, though. Abell 2744 had a higher ratio of orbits committed to F814W. I have now officially managed to confuse myself. This is disturbingly easy for me to do, lately.

The lensing seems typical at first but after staring at it for a while during processing, I realized that there is more to it. If you draw a line from the bottom right to the upper left, this creates a rough axis along which many mirror images are formed. There is a lot of bilateral symmetry among individual objects but also the overall structure of the lens looks like it has some kind of rough bilateral symmetry along this diagonal line. Very interesting.

Here is the Frontier Fields page for MACSJ0416 at MAST. Datasets can be found here.

Red: hlsp_frontier_hst_acs-30mas-selfcal_macs0416_f814w_v1.0_drz Green: hlsp_frontier_hst_acs-30mas-selfcal_macs0416_f606w_v1.0_drz Blue: hlsp_frontier_hst_acs-30mas-selfcal_macs0416_f435w_v1.0_drz

North is NOT up. It is 23° counter-clockwise from up.