Results 71 to 80 of about 50,755 (263)

A High Fraction of Heavily X-Ray-obscured Active Galactic Nuclei

The Astrophysical Journal, 2023
We present new estimates on the fraction of heavily X-ray-obscured, Compton-thick (CT) active galactic nuclei (AGNs) out to a redshift of z ≤ 0.8. From a sample of 540 AGNs selected by mid-infrared (MIR) properties in observed X-ray survey fields, we ...
Christopher M. Carroll, Tonima T. Ananna, Ryan C. Hickox, Alberto Masini, Roberto J. Assef, Daniel Stern, Chien-Ting J. Chen, Lauranne Lanz   +7 more
doaj   +1 more source

Aptamer Engineering: Strategies for Discovering Functional Nucleic Acids for Next‐Generation Diagnostics and Biosensing

Advanced Science, Volume 13, Issue 2, 9 January 2026.
The advent of aptamers has highlighted their potential as alternatives to antibodies, overcoming limitations of structural instability and production cost. However, conventional approaches such as SELEX remain slow and labor‐intensive. This review examines recent advances in aptamer engineering, emphasizing in vitro and AI‐driven in silico strategies ...
John V. L. Nguyen, Ahlem Meziadi, Cyrill Brunner, Maureen McKeague, Lidija Malic, Maryam Tabrizian   +5 more
wiley   +1 more source

The Response of Warm Absorbers to the Variations in the Ionizing Continuum in the Active Galaxy NGC 4051

The Astrophysical Journal
We present a time-resolved X-ray spectral analysis of the warm absorbers in the Seyfert galaxy NGC 4051, which has an active galactic nucleus (AGN), using observations from the Neutron Star Interior Composition Explorer (NICER).
Dev R. Sadaula, Timothy R. Kallman, Sibasish Laha   +2 more
doaj   +1 more source

The Most Obscured AGNs in the XMM-SERVS Fields

The Astrophysical Journal, 2023
We perform X-ray spectral analyses to derive the characteristics (e.g., column density, X-ray luminosity) of ≈10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey, which was designed to investigate the growth
Wei Yan, W. N. Brandt, Fan Zou, Shifu Zhu, Chien-Ting J. Chen, Ryan C. Hickox, Bin Luo, Qingling Ni, David M. Alexander, Franz E. Bauer, Cristian Vignali, Fabio Vito   +11 more
doaj   +1 more source

Magnetic reconnection: flares and coronal heating in Active Galactic Nuclei [PDF]

, 1998
A magnetically-structured accretion disk corona, generated by buoyancy instability in the disk, can account for observations of flare--like events in Active Galactic Nuclei.
Di Matteo, T.
core   +3 more sources

Spin Matters: A Multidisciplinary Roadmap to Understanding Spin Effects in Oxygen Evolution Reaction During Water Electrolysis

Advanced Energy Materials, Volume 16, Issue 4, 28 January 2026.
This roadmap offers a forward‐looking perspective on spin enhancement in the oxygen evolution reaction. It highlights how combining systematic experiments, advanced computational modeling, and novel magnetic, chiral, or hybrid materials can deepen the understanding of spin‐dependent catalytic mechanisms.
Emma van der Minne, Priscila Vensaus, Vadim Ratovskii, Seenivasan Hariharan, Jan Behrends, Cesare Franchini, Jonas Fransson, Sarnjeet S. Dhesi, Felix Gunkel, Florian Gossing, Georgios Katsoukis, Ulrike I. Kramm, Magalí Lingenfelder, Qianqian Lan, Yury V. Kolen'ko, Yang Li, Ramsundar Rani Mohan, Jeffrey McCord, Lingmei Ni, Eva Pavarini, Rossitza Pentcheva, David H. Waldeck, Michael Verhage, Anke Yu, Zhichuan J. Xu, Piero Torelli, Silvia Mauri, Narcis Avarvari, Anja Bieberle‐Hütter, Christoph Baeumer   +29 more
wiley   +1 more source

A Simple Method for Predicting N H Variability in Active Galactic Nuclei

The Astrophysical Journal, 2023
The unified model of active galactic nuclei (AGNs) includes a geometrically thick obscuring medium to explain the differences between type I and type II AGNs as an effect of inclination angle.
Isaiah S. Cox, Núria Torres-Albà, Stefano Marchesi, Xiurui Zhao, Marco Ajello, Andrealuna Pizzetti, Ross Silver   +6 more
doaj   +1 more source

A systematic cross-search for radio/infrared counterparts of XMM-Newton sources

, 2010
We present a catalog of cross-correlated radio, infrared and X-ray sources using a very restrictive selection criteria with an IDL-based code developed by us.
A. Caccianiga, A. J. Muñoz-Arjonilla, A.D.P. Hands, A.J. Green, B.J. Boyle, C. Feruglio, E. Sánchez-Ayaso, F.J. Carrera, G. E. Romero, G. Fabbiano, G. Micela, G. Novara, I. Furenlid, J. A. Combi, J. Ebrero, J. F. Albacete Colombo, J. López-Santiago, J. López-Santiago, J. Martí, J. R. Sánchez-Sutil, J.J. Condon, J.R. Allington-Smith, L. Pellizza, M. Seldner, M.G. Watson, P. L. Luque-Escamilla, P. Severgnini, P.J.E. Peebles, P.M. Woodward, R. Della Ceca, R. Della Ceca, R.K. Smith, S. Mateos, S. Mateos, X. Barcons, X. Barcons   +35 more
core   +1 more source

Self‐Healing Materials from Electronically Integrated Microscopic Robots

Advanced Intelligent Systems, Volume 8, Issue 1, January 2026.
Submillimeter robots can use electronically controlled electrodeposition to assemble into a material structure. The resulting aggregate possesses ultralow density, high strength‐to‐weight ratio, and can heal from damage. Further afield, these results clear a path to materials that organize or adapt by directing matter and information at the microscale.
Lucas C. Hanson, William H. Reinhardt, Marc Z. Miskin   +2 more
wiley   +1 more source

A Systematic Search for X-Ray Eclipse Events in Active Galactic Nuclei Observed by Swift

The Astrophysical Journal
The nuclear regions of active galactic nuclei (AGNs) likely host clumpy clouds that occasionally obscure the central X-ray source, causing eclipse events. These events offer a unique opportunity to study the properties and origins of such clouds. However,
Tianying Lian, Chichuan Jin, Weimin Yuan
doaj   +1 more source