How we far can we go? What are most distant objects Hubble can possibly see? Can we get a sneak peak at the first galaxies and stars before the launch of the James Webb Space Telescope?
These are the key questions we hope to answer with the new HST Frontier Fields campaign. Based on the recommendations of the Hubble Deep Fields Initiative working group, the STScI Director Matt Mountain has decided to pursue a program to push Hubble’s capabilities to its limits. This will be accomplished by combining the power of Hubble with the natural gravitational telescopes of high-magnification clusters of galaxies. Over the next three years, Hubble will obtain the deepest ever optical and IR images of six clusters, in parallel with the second-deepest images of six neighboring “blank” fields. In addition, the Spitzer Space Telescope will use ~1000 DD hours to obtain very deep IRAC imaging at 3.6 and 4.5 microns.
By choosing the clusters carefully — selecting the best known lensers, in the darkest parts of the sky, at redshifts distant enough that the cluster galaxies appear small — this program is expected to obtain observations of very distant lensed galaxies ~10-50x intrinsically fainter than anything detectable in the Ultra Deep Field. Some of the z ~8 galaxies may be boosted enough that spectroscopic follow-up will be possible. In addition, the parallel blank fields will triple the area observed to ~28.7-29th magnitude depths with HST. This will greatly improve our statistical understanding of the unlensed high-redshift galaxy population, and provide a meaningful control sample for the deep cluster observations.
We here at STScI have put together our core team that will make this happen. A great many things need to come together before the Frontier Fields become reality – the selection of the fields, creating the detailed HST observing plan and schedule, optimizing HST’s calibrations for very deep imaging, testing the data reduction pipeline, coordinating with Spitzer Space Telescope and other observatories, creating education/outreach materials, and so on.
This blog is here to keep the astronomy community up to date on the latest developments. I hope this will also convey what it is that the scientists and staff here at STScI do in order to keep HST at the forefront of science. Finally, our goal is to make this campaign as open a process as possible – comments and more significant contributions are very welcome.
Here’s to a new year filled with discovery –
HST Frontier Fields Team Lead
Associate Astronomer, STScI