Results 81 to 90 of about 74,488 (217)
The Astrophysical JournalWe assess the systematics and efficiency of an active galactic nucleus (AGN) selection method based on mid-infrared (MIR) variability. To this end, we utilize various types of active and inactive galaxies from the Sloan Digital Sky Survey, matching them ...
Shinyu Kim +3 more
doaj +1 more source
Reverberation mapping of active galactic nuclei: from X-ray corona to dusty torus. [PDF]
iScience, 2021 Cackett EM, Bentz MC, Kara E.
europepmc +1 more source
Miscellaneous observations of active galactic nuclei. II
, 1997 We observed 37 AGN candidates and classified them on the basis of their spectroscopic properties; three are confirmed QSOs, one is a BL Lac object, nine are Seyfert 1 galaxies, four Seyfert 2s, while twenty are HII regions.Comment: LaTeX 2e, 15 pages (4 ...
Goncalves, A. C. +2 more
core +1 more source
Spaceborne and spaceborn: Physiological aspects of pregnancy and birth during interplanetary flight
Experimental Physiology, EarlyView.Abstract Crewed interplanetary return missions that are on the planning horizon will take years, more than enough time for initiation and completion of a pregnancy. Pregnancy is viewed as a sequence of processes – fertilization, blastocyst formation, implantation, gastrulation, placentation, organogenesis, gross morphogenesis, birth and neonatal ...
Arun V. Holden
wiley +1 more source
Transient Relativistic Iron Emission Line from an X-Ray Flaring Supermassive Black Hole
The Astrophysical JournalWe report the discovery of the first transient relativistic iron K α line in an active galactic nucleus (AGN), J1047+5907. The line was detected 21.5 days (rest frame) after an X-ray coronal flare was observed in 2008, and it exhibits significant ...
Xiurui Zhao +18 more
doaj +1 more source
Detecting the 21 cm Forest in the 21 cm Power Spectrum
, 2014 We describe a new technique for constraining the radio loud population of active galactic nuclei at high redshift by measuring the imprint of 21 cm spectral absorption features (the 21 cm forest) on the 21 cm power spectrum.
Dillon, Joshua S. +3 more
core +1 more source
Building a Continental‐Scale Geodetic Network: The Plate Boundary Observatory (PBO)
Perspectives of Earth and Space Scientists, Volume 7, Issue 1, December 2026.Abstract The Plate Boundary Observatory (PBO) transformed the use of geodesy in North America to study crustal deformation and plate boundary processes by establishing a continental‐scale, standardized, open‐access geodetic network. Built and operated by UNAVCO between 2003 and 2018 as part of the National Science Foundation (NSF)‐funded EarthScope ...
Emily E. Zawacki +5 more
wiley +1 more source
XRISM Discovery of Multiple Ionized Fe-K Emission and Absorption Components in Centaurus A
The Astrophysical JournalWe present the first clear detection of ionized Fe-K emission and absorption components in the nearby radio galaxy Centaurus A, revealed by the high-resolution XRISM/Resolve detector.
Taishu Kayanoki +15 more
doaj +1 more source
Early evolutionary history of the seed
Biological Reviews, Volume 101, Issue 3, Page 1511-1553, June 2026.ABSTRACT The seed is an essential stage in the life history of gymnospermous and angiospermous plants, facilitating both their survival and dispersal. We reappraise knowledge of the evolutionary history of the gymnospermous seed, from its origin in the late Devonian through to the well‐known end‐Permian extinctions – an interval encompassing the ...
Richard M. Bateman +2 more
wiley +1 more source
Reducing the Dimensions of Active Galactic Nuclei Light-curve Manifolds
The Astrophysical JournalThe active galactic nuclei (AGNs) glossary is vast and complex. Depending on the selection method, observing wavelength, and brightness, AGNs are assigned distinct labels, yet the relationship between different selection methods and the diversity of time-
Shoubaneh Hemmati +12 more
doaj +1 more source