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The first public 0.9–4.4 μ m NIRCam images of the North Ecliptic Pole Time Domain Field uncovered galaxies displaying point-source features in their cores as seen in the longer-wavelength filters. We visually identified a sample of 66 galaxies (∼1 galaxy arcmin ^–2 ) with pointlike cores and have modeled their two-dimensional light profiles with GalFit , identifying 16 galactic nuclei with measurable point-source components. GalFit suggests that the visual sample is a mix of both compact stellar bulge and point-source galaxy cores. This core classification is complemented by spectral energy distribution modeling to infer the sample’s active galactic nucleus (AGN) and host-galaxy parameters. For galaxies with measurable point-source components, the median fractional AGN contribution to their 0.1–30.0 μ m flux is 0.44, and 14/16 are color-classified AGN. We conclude that near-infrared point-source galaxy cores are signatures of AGN. In addition, we define an automated sample-selection criterion to identify these point-source features. This criterion can be used in other extant and future NIRCam images to streamline the search for galaxies with unresolved IR-luminous AGN. The James Webb Space Telescope’s superb angular resolution and sensitivity at infrared wavelengths are resurrecting the morphological identification of AGN.

The James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-domain Field (TDF) is a >14′ diameter field optimized for multiwavelength time-domain science with JWST. It has been observed across the electromagnetic spectrum both from the ground and from space, including with the Hubble Space Telescope (HST). As part of HST observations over three cycles (the “TREASUREHUNT” program), deep images were obtained with the Wide Field Camera on the Advanced Camera for Surveys in F435W and F606W that cover almost the entire JWST NEP TDF. Many of the individual pointings of these programs partially overlap, allowing an initial assessment of the potential of this field for time-domain science with HST and JWST. The cumulative area of overlapping pointings is ∼88 arcmin ^2 , with time intervals between individual epochs that range between 1 day and 4+ yr. To a depth of m _AB ≃ 29.5 mag (F606W), we present the discovery of 12 transients and 190 variable candidates. For the variable candidates, we demonstrate that Gaussian statistics are applicable and estimate that ∼80 are false positives. The majority of the transients will be supernovae, although at least two are likely quasars. Most variable candidates are active galactic nuclei (AGNs), where we find 0.42% of the general z ≲ 6 field galaxy population to vary at the ∼3 σ level. Based on a 5 yr time frame, this translates into a random supernova areal density of up to ∼0.07 transients arcmin ^−2 (∼245 deg ^−2 ) per epoch and a variable AGN areal density of ∼1.25 variables arcmin ^−2 (∼4500 deg ^−2 ) to these depths.

We present the second NuSTAR and XMM-Newton extragalactic survey of the JWST north ecliptic pole (NEP) time-domain field (TDF). The first NuSTAR NEP-TDF survey had 681 ks total exposure time executed in NuSTAR cycle 5 in 2019 and 2020. This second survey, acquired from 2020 to 2022 in cycle 6, adds 880 ks of NuSTAR exposure time. The overall NuSTAR NEP-TDF survey is the most sensitive NuSTAR extragalactic survey to date, and a total of 60 sources were detected above the 95% reliability threshold. We constrain the hard X-ray number counts, $\mathrm{log}N$ – $\mathrm{log}S$ , down to 1.7 × 10 ^−14 erg cm ^−2 s ^−1 at 8–24 keV and detect an excess of hard X-ray sources at the faint end. About 47% of the NuSTAR-detected sources are heavily obscured ( N _H > 10 ^23 cm ^−2 ), and ${18}_{-8}^{+20}$ % of the NuSTAR-detected sources are Compton-thick ( N _H > 10 ^24 cm ^−2 ). These fractions are consistent with those measured in other NuSTAR surveys. Four sources presented >2 σ variability in the 3 yr survey. In addition to NuSTAR, a total of 62 ks of XMM-Newton observations were taken during NuSTAR cycle 6. The XMM-Newton observations provide soft X-ray (0.5–10 keV) coverage in the same field and enable more robust identification of the visible and infrared counterparts of the NuSTAR-detected sources. A total of 286 soft X-ray sources were detected, out of which 214 XMM-Newton sources have secure counterparts from multiwavelength catalogs.

The diffuse, unresolved sky provides most of the photons that the Hubble Space Telescope (HST) receives, yet remains poorly understood. The HST Archival Legacy program SKYSURF aims to measure the 0.2–1.6 μ m sky surface brightness (sky-SB) from over 140,000 HST images. We describe a sky-SB measurement algorithm designed for SKYSURF that is able to recover the input sky-SB from simulated images to within 1% uncertainty. We present our sky-SB measurements estimated using this algorithm on the entire SKYSURF database. Comparing our sky-SB spectral energy distribution (SED) to measurements from the literature shows general agreements. Our SKYSURF SED also reveals a possible dependence on the Sun angle, indicating either nonisotropic scattering of solar photons off interplanetary dust or an additional component to zodiacal light. Finally, we update the diffuse light limits in the near-IR based on the methods from Carleton et al., with values of 0.009 MJy sr ^−1 (22 nW m ^−2 sr ^−1 ) at 1.25 μ m, 0.015 MJy sr ^−1 (32 nW m ^−2 sr ^−1 ) at 1.4 μ m, and 0.013 MJy sr ^−1 (25 nW m ^−2 sr ^−1 ) at 1.6 μ m. These estimates provide the most stringent all-sky constraints to date in this wavelength range. SKYSURF sky-SB measurements are made public on the official SKYSURF website and will be used to constrain diffuse light in future papers.

We present an overview of the CANDELS Ly α Emission At Reionization (CLEAR) survey. CLEAR is a 130 orbit program of the Hubble Space Telescope using the Wide Field Camera 3 (WFC3) IR G102 grism. CLEAR targets 12 pointings divided between the GOODS-N and GOODS-S fields of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). Combined with existing spectroscopic data from other programs, the full CLEAR data set includes spectroscopic imaging of these fields over 0.8–1.7 μ m. In this paper, we describe the CLEAR survey, the survey strategy, the data acquisition, reduction, processing, and science products and catalogs released alongside this paper. The catalogs include emission line fluxes and redshifts derived from the combination of the photometry and grism spectroscopy for 6048 galaxies, primarily ranging from 0.2 ≲ z ≲ 3. We also provide an overview of CLEAR’s science goals and results. In conjunction with this paper we provide links to electronic versions of the data products, including 1D+2D extracted spectra and emission line maps.

We give an overview and describe the rationale, methods, and first results from NIRCam images of the JWST “Prime Extragalactic Areas for Reionization and Lensing Science” (PEARLS) project. PEARLS uses up to eight NIRCam filters to survey several prime extragalactic survey areas: two fields at the North Ecliptic Pole (NEP); seven gravitationally lensing clusters; two high redshift protoclusters; and the iconic backlit VV 191 galaxy system to map its dust attenuation. PEARLS also includes NIRISS spectra for one of the NEP fields and NIRSpec spectra of two high-redshift quasars. The main goal of PEARLS is to study the epoch of galaxy assembly, active galactic nucleus (AGN) growth, and First Light. Five fields—the JWST NEP Time-Domain Field (TDF), IRAC Dark Field, and three lensing clusters—will be observed in up to four epochs over a year. The cadence and sensitivity of the imaging data are ideally suited to find faint variable objects such as weak AGN, high-redshift supernovae, and cluster caustic transits. Both NEP fields have sightlines through our Galaxy, providing significant numbers of very faint brown dwarfs whose proper motions can be studied. Observations from the first spoke in the NEP TDF are public. This paper presents our first PEARLS observations, their NIRCam data reduction and analysis, our first object catalogs, the 0.9–4.5 μ m galaxy counts and Integrated Galaxy Light. We assess the JWST sky brightness in 13 NIRCam filters, yielding our first constraints to diffuse light at 0.9–4.5 μ m. PEARLS is designed to be of lasting benefit to the community.