sci14011 — Announcement

Hubble Frontier Fields milestone

29 July 2014

On 1 July 2014, the NASA/ESA Hubble Space Telescope and NASA’s Spitzer Space Telescope completed deep imaging of the galaxy cluster Abell 2744 (above left) and a nearby "blank" field (above right), as part of the Frontier Fields programme.

The blank field image is nearly as deep as the Ultra Deep Field, and the cluster image peers even deeper into the Universe thanks to the cluster's strong gravitational lensing.

Six pairs of images like these will be observed with Director's Discretionary Time (DDT) over the course of the three-year programme led by Jennifer Lotz (STScI).

A number of papers have already been written based on incomplete observations of the first two image pairs (including the pair above). Deep near-infrared Hubble imaging has yielded many distant galaxy candidates out to z ~ 9 and Spitzer infrared imaging has constrained the restframe optical properties and emission line strengths of these young galaxies.

Strong candidates beyond z > 9 (the first 500 Myr) have yet to be identified in the numbers expected. Similar z > 9 deficits reported in previous Hubble imaging suggest a rapid build-up in galaxy numbers during the first 500 million years. The full Frontier Fields programme will deliver improved statistics and mitigate cosmic variance to confirm or controvert this claim.

The deep cluster images have revealed unprecedented numbers of strongly lensed galaxies, including nJy (AB mag > 31) sources, the faintest yet observed. These many lensed galaxies are constraining cluster dark matter and magnification maps better than ever before and the accuracy of these magnification maps is being tested, in part, by the occasional lensed supernova with a roughly known intrinsic brightness.

Additional new data on the Frontier Fields are being obtained by other observing programmes with Hubble as well as other observatories including Chandra, ALMA, VLT and Gemini.

For more information, data products, and a list of publications, please see:



Antonella Nota
ESA HST Project Scientist, STScI

About the Announcement



Frontier Fields: Abell 2744 and “blank” field comparison
Frontier Fields: Abell 2744 and “blank” field comparison

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