The James Webb Space Telescope
North Ecliptic Pole Time Domain Field

Thanks to its superior angular resolution, low background, and exquisite infrared sensitivity, the James Webb Space Telescope (JWST) will allow an unprecedented look at the distant universe back to the first stars, galaxies and black holes. And only the Chandra X-ray Telescope has the necessary angular resolution to unambiguosly identify the high-energy components of these objects.

JWST's capabilities come with trade-offs, though: its field-of-view is very small, and to maintain its sensitivity JWST must be shielded from the sun. Only a very small portion of the sky (at Earth's Ecliptic Poles) can therefore be targeted at any time of the year.

Shortly after launch, JWST will target a carefully chosen field near the North Ecliptic Pole named the The James Webb Space Telescope
North Ecliptic Pole Time Domain Field
; GTO 1176, PI Rogier Windhorst). Because the JWST-NEP-TDF can be observed at any time of the year and has very low infrared background, it will be the ultimate field for deep time domain science across cosmic time with JWST. We also anticipate that this ease of access will result in repeated visits that will, in the long run, produce the deepest possible co-added images with JWST.

Building a Deep Chandra Component

I am leading efforts to develop a deep, high-resolution X-ray counterpart to this unique JWST field. JWST will be able to study the earliest supermassive black holes, black holes from the first stars, and luminous transients across cosmic time. Sensitive X-ray observations will be necessary to investigate these highly energetic phenomena, so we are in the process of observing the JWST-NEP-TDF with Chandra. Other deep fields observed by Chandra (e.g. the Chandra Deep Field South, Chandra Deep Field North, AEGIS) have revolutionized our understanding of galaxy evolution. These fields will be observed by JWST, but none will be mapped as easily, efficiently, or deeply as JWST-NEP-TDF.

JWST will essentially find all of the rest-frame UV/optical/IR counterparts to photons detected by Chandra from this field.

The deepest possible Chandra data are therefore essential for JWST-NEP-TDF, and four successive Chandra time allocation panels have therefore awarded new observations of JWST-NEP-TDF totaling 1.8 megaseconds which will bring JWST-NEP-TDF ever-closer to CDF-N depth.

Along with very deep HST and ground-based optical, infrared and radio data, Chandra observations of JWST-NEP-TDF are enabling an exciting and powerful multi-wavelength field well in advance of JWST launch.

Essential Links

For a more detailed look at the science and multi-wavelength developments, please check out our preliminary work and field design:

Maksym et al 2019 Winter AAS Poster (PDF) describing the design and preliminary results of the Chandra field.

Jansen & Windhorst 2018, PASP, 130, 124001 paper describing the JWST survey design.

Jansen et al 2019 Winter AAS Poster (PDF) describing HST survey design and progress.

Jansen et al 2018 Winter AAS Poster (PDF) describing HST survey design and progress.

Jansen et al 2017 Summer AAS Poster (PDF) describing the design of the JWST field.