The Roman eXtreme Deep Field (RXDF)

Haojing Yan, Anton M. Koekemoer, Yue Shen, Bangzheng Sun, Norman A. Grogin, Zihao Wu, Christian Kragh Jespersen, Rachel Somerville, Kyoung-Soo Lee, Dale D. Kocevski, Adam J. Burgasser, Pedro H. Bernardinelli, Yicheng Guo, Charles Steinhardt, Xiaohui Fan, Duncan Farrah, Gisella De Rosa, Feige Wang, Jinyi Yang, Lifan Wang, Fengwu Sun, Christopher N. A. Willmer, John David Silverman, Steven L. Finkelstein, Seth H. Cohen, Rolf A. Jansen, Rogier A. Windhorst, Brent M. Smith, Stefano Casertano, Anthony H. Gonzalez, Michael A. Strauss, Ray A. Lucas, Katherine E. Whitaker, Mingyang Zhuang, Rodrigo Angulo, Chloe Aurin, Micaela Bagley, Franz E. Bauer, Jessica M. Berkheimer, Rachel Bezanson, Alejandro S. Borlaff, Rebecca A. A. Bowler, Larry D. Bradley, W. N. Brandt, Denis Burgarella, Timothy Carleton, Delondrae D. Carter, Caitlin M. Casey, Christopher J. Conselice, Kyle W. Cook, Jeff Cooke, David A. Coulter, Tyler Desjardins, Tim Dewachter, Nicole E. Drakos, Simon P. Driver, Qiao Duan, Eiichi Egami, Andreas Faisst, Travis C. Fischer, Adriano Fontana, Ori Fox, Brenda Frye, Yoshinobu Fudamoto, Eric Gawiser, Mauro Giavalisco, Yuichi Harikane, Thomas Harvey, Nimish P. Hathi, Benne W. Holwerda, Taylor Hutchison, Olivier Ilbert, Akio K. Inoue, Lucy R. Ivey, Kartheik Iyer, Mathilde Jauzac, Ignas Juodzbalis, Jeyhan S. Kartaltepe, Daichi Kashino, Susan Kassin, Patrick Kelly, Kotaro Kohno, Stephanie LaMassa, Erini Lambrides, Rebecca Larson, Junyao Li, Zhiyuan Ma, Sangeeta Malhotra, Elizabeth McGrath, Peter Melchior, Marcio Melendez, Hironao Miyatake, Bahram Mobasher, Mireia Montes, Thomas Moore, Takahiro Morishita, Takashi Moriya, Leonidas Moustakas, Rohan Naidu, Rosalia O'Brien, Pascal A. Oesch, Masafusa Onoue, Rafael Ortiz, Masami Ouchi, Robert G. Pascalau, Molly Peeples, Andreea O. Petric, Sara Petty, Justin Pierel, Marc Rafelski, Eniko Regos, Armin Rest, Mitchell Revalski, James Rhoads, Pierluigi Rinaldi, Aaron Robotham, Kate Rowlands, Pablo M. Sanchez-Alarcon, Paola Santini, Alice E. Shapley, Raymond C. Simons, Swara Ravindranath, Takahiro Sumi, Takumi S. Tanaka, Masayuki Tanaka, Scott Tompkins, Christina C. Williams, Edward J. Wollack, John F. Wu, L. Y. Aaron Yung

First listed 2026-09-09 | Last updated 2026-09-08

Abstract

The Roman eXtreme Deep Field (RXDF) program is one of the five General Astrophysics Survey (GAS) programs approved for observing time with the Nancy Grace Roman Space Telescope in Cycles 1 and 2. It has been allocated 386.41 hours to carry out an imaging survey to AB = 30 mag (5-sigma) over ~140x larger area than the Hubble eXtreme Deep Field (HXDF) full-depth area (ACS+WFC3/IR). The RXDF will cover the full Roman wavelength range with 7 bands, reaching AB = 30 mag in RZYJH, 29 mag in F, and 28 mag in K, over a full-depth area of 678.75 arcmin^2 embedded in a total area of 1,243 arcmin^2, and far exceeding the depths of the Roman Core Community Surveys (CCS). The RXDF is within the Euclid Ultra Deep Field (EUDF) near the North Ecliptic Pole (NEP), a strategic long-term field for generational space facilities, with a wealth of multi-wavelength data including extensive coverage from the James Webb Space Telescope (JWST) NEXUS Treasury program. The observations will cover 3 epochs at a 1-year cadence, each epoch divided into 3 sub-epochs ~10 days apart, enabling time-domain studies on time baselines from ~10 days to over ~2 years. The RXDF is uniquely positioned to address critical questions in reionization, large scale structure (LSS), growth of supermassive black holes (SMBHs), little red dots (LRDs), and high-z supernovae (SNe); the volumes probed by HST+JWST are too small at these extreme depths, and even the deepest CCS tiers are too shallow. In addition to our key objectives, a wealth of additional science will be enabled by engaging the community with our rapidly released datasets, revolutionizing a wide range of science for a lasting legacy. This short document, which is converted from the approved RXDF proposal, aims to provide the community with a summary of the program.

Short digest

This program paper defines the Roman eXtreme Deep Field (RXDF), a Cycle 1–2 Roman imaging survey designed to reach AB = 30 mag over 678.75 arcmin² at full depth, with contiguous coverage totaling 1,243 arcmin² across seven Roman bands. Its central advance for the LRD and early-SMBH community is deep, wide-area imaging in the Euclid Ultra Deep Field near the North Ecliptic Pole, overlapping the JWST NEXUS Treasury field and substantially enlarging the volume available for rare AGN, LRD, and luminous-galaxy searches. Three annual epochs, each split into sub-epochs roughly 10 days apart, add variability baselines from about 10 days to more than two years, enabling time-domain discrimination and transient science alongside population measurements. The survey is positioned to reduce cosmic-variance limitations that currently dominate extreme-depth HST and JWST fields while extending LRD searches to substantially lower luminosities at cosmic noon.

Key figures to inspect

• Figure 3. This is the operational survey-definition figure: it shows how the customized eight-point dithering and shifted centers fill detector gaps across nine sub-epochs, producing the 678.75 arcmin² full-depth region and 1,243 arcmin² contiguous footprint that underpin the program’s rare-object statistics.
• Figure 4. This figure places RXDF within the Euclid Ultra Deep Field and JWST NEXUS footprint, then compares its depth and area directly with the Hubble eXtreme Deep Field, existing JWST surveys, and Roman HLTDS. It is the clearest visual summary of why RXDF occupies a distinct depth–area regime.
• Figure 5. This cosmic-variance calculation makes the survey’s core statistical case, showing how RXDF’s area changes the probability of finding the brightest high-redshift galaxies relative to JADES and HUDF-sized fields. The same volume advantage is directly relevant to constraining rare LRD and AGN populations.
• Figure 7. The right-hand luminosity–redshift comparison is the most directly relevant science forecast for this archive: RXDF is projected to yield a high-redshift AGN sample comparable in depth to the deepest JWST samples but 30–50 times larger, while reaching cosmic-noon LRD luminosities roughly ten times below those accessible for high-redshift JWST LRDs.