Feb 052014

Nicolas Laporte and collaborators have compared the deep HST images of Frontier Fields cluster Abell 2744 to 50 hours of Spitzer IRAC imaging.  One of the best candidates for a distant z~8 galaxy — detected in the HST  WFC3/IR images — disappears in the IRAC 3.6 micron image and reappears in the IRAC 4.5 micron image.   The best explanation for these strange colors is the appearance of very strong emission lines from oxygen and hydrogen ([OIII] and H-beta) which fall into the 4.5 micron band at a redshift of z~7.98.

The paper has been accepted for publication in the A&A Letters.

Check out the details: http://arxiv.org/abs/1401.8263v1.

JWST will be able to provide conclusive observations with both NIRSpec and NIRCam grism observations.  Bring on 2018 and the launch of JWST!

 Posted by at 12:37 pm
Oct 232013

Frontier Fields got our very first data last week and we already have a discovery!

Jennifer Lotz discovered a supernova in the ACS F814W images of MACSJ0717!  See the full announcement for details.

We will also be getting early data for MACSJ1149 and its parallel field on November 3 (schedule), to get some initial imaging of the previously unobserved parallel field and test out a new HST guide star.  The  new WFC3/IR imaging of MACSJ1149 also can be compared to old images to search for supernovae and other transients.

Congratulations!  This is a most auspicious start to the program!

 Posted by at 1:39 pm