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 μm 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 μm. PEARLS is designed to be of lasting benefit to the community.
We present the analysis of a sample of 35 candidate Compton thick (CT-) active galactic nuclei (AGNs) selected in the nearby Universe (average redshift z ∼0.
In modeling the X-ray spectra of active galactic nuclei (AGNs), the inclination angle is a parameter that can play an important role in analyzing the X-ray spectra of AGNs, but it has never been studied in detail. We present a broadband X-ray spectral analysis of the joint Nuclear Spectroscopic Telescope Array-XMM-Newton observations of 13 sources with [O iii] measured inclinations determined by Fischer et al. By freezing the inclination angles at the [O iii] measured values when modeling the observations, the spectra are well fitted, and the geometrical properties of the obscuring structure of the AGNs are slightly better constrained than those fitted when the inclination angles are left free to vary. We also test if one could freeze the inclinations at other specific angles in fitting the AGN X-ray spectra as has been commonly done in the literature. We find that one should always let the inclination angle be free to vary in modeling the X-ray spectra of AGNs, while fixing the inclination angle at [O iii] measured values and fixing the inclination angle at 60° also present correct fits of the sources in our sample. Correlations between the covering factor and the average column density of the obscuring torus with respect to the Eddington ratio are also measured, suggesting that the distribution of the material in the obscuring torus is regulated by the Eddington ratio, which is in agreement with previous studies. In addition, no geometrical correlation is found between the narrow line region of the AGN and the obscuring torus, suggesting that the geometry might be more complex than what is assumed in the simplistic unified model.
The obscuration observed in active galactic nuclei (AGNs) is mainly caused by dust and gas distributed in a torus-like structure surrounding the supermassive black hole. However, the properties of the obscuring torus of an AGN in X-ray have not yet been fully investigated because of a lack of high-quality data and proper models. In this work, we perform a broadband X-ray spectral analysis of a large, unbiased sample of obscured AGNs (with line-of-sight column density 23 ≤ log(NH) ≤ 24) in the nearby Universe for which high-quality archival NuSTAR data are available. We analyzed the source spectra using the recently developed borus02 model, which enables us to accurately characterize the physical and geometrical properties of AGN-obscuring tori. We compare our results obtained from the unbiased Compton-thin AGNs with those of Compton-thick AGNs. We find that Compton-thin and Compton-thick AGNs may possess similar tori, whose average column density is Compton thick (NH, tor, ave ≈ 1.4 × 1024 cm−2), but they are observed through different (under-dense or over-dense) regions of the tori. We also find that the obscuring torus medium is significantly inhomogeneous, with the torus average column densities being significantly different from their line-of-sight column densities (for most of the sources in the sample). The average torus covering factor of sources in our unbiased sample is cf = 0.67, suggesting that the fraction of unobscured AGNs is ∼33%. We developed a new method to measure the intrinsic line-of-sight column density distribution of AGNs in the nearby Universe, and find the results to be in good agreement with constraints from recent population synthesis models.
We present the analysis of simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR) and XMM-Newton data of eight Compton-thick active galactic nuclei (CT-AGN) candidates selected in the Swift-BAT 100 month catalog. This work is part of an ongoing effort to find and characterize all CT-AGN in the Local (z ≤ 0.05) Universe. We used two physically motivated models, MYTorus and borus02, to characterize the sources in the sample, finding five of them to be confirmed CT-AGN. These results represent an increase of ∼19% over the previous NuSTAR-confirmed, BAT-selected CT-AGN at z ≤ 0.05, bringing the total number to 32. This corresponds to an observed fraction of ∼8% of all AGN within this volume-limited sample, although it increases to 20% ± 5% when limiting the sample to z ≤ 0.01. Out of a sample of 48 CT-AGN candidates, selected using BAT and soft (0.3−10 keV) X-ray data, only 24 are confirmed as CT-AGN with the addition of the NuSTAR data. This highlights the importance of NuSTAR when classifying local obscured AGN. We also note that most of the sources in our full sample of 48 Seyfert 2 galaxies with NuSTAR data have significantly different lines of sight and average torus column densities, favoring a patchy torus scenario.
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