Results 111 to 120 of about 78,490 (277)

Gamma rays from active galactic nuclei [PDF]

open access: yes
The general properties of Active Galactic Nuclei (AGN) and quasars are reviewed with emphasis on their continuum spectral emission. Two general classes of models for the continuum are outlined and critically reviewed in view of the impending GRO (Gamma ...
Kazanas, Demosthenes
core   +1 more source

The Correlation between X-ray spectral slope and FeKalpha line energy in radio-quiet active galactic nuclei

open access: yes, 2002
A significant correlation between FeKalpha line energy and X-ray spectral slope has been discovered among radio-quiet active galactic nuclei. The ionization stage of the bulk of the FeKalpha emitting material is not the same in all active galactic nuclei
Arnaud K. A.   +14 more
core   +1 more source

Reverberation mapping of active galactic nuclei

open access: yesAstronomische Nachrichten, 2004
AbstractEcho mapping makes use of the intrinsic variaibility of the continuum source in active galactic nuclei to map out the distribution and kinematics of line‐emitting gas from its light travel time‐delayed response to continuum changes. Echo mapping experiments have yielded sizes for the broad line‐emitting region in about three dozen AGNs.
Keith Horne, Bradley M. Peterson
openaire   +4 more sources

A Small Pathbreaking Spacecraft: Giants of Space Research (Bernard Blake, Dieter Hovestadt, and Edward Stone)

open access: yesPerspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.
Abstract The Solar, Anomalous, and Magnetospheric Explorer (SAMPEX) mission launched in July 1992 was the first NASA “Small Explorer” project. It had the goal to show how space missions could be developed much more rapidly than had become the situation in the 1980s and 1990s.
D. N. Baker, G. M. Mason
wiley   +1 more source

A History of UNAVCO: Four Decades of Advancing Geodesy

open access: yesPerspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.
Abstract UNAVCO was a university‐governed consortium funded by the National Science Foundation (NSF), with support from the National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS), to support geoscience research and education using geodesy.
Emily E. Zawacki   +4 more
wiley   +1 more source

X-Ray Polarization Variability of High Spectral Peak BL Lacertaes: Cases of 1ES 1959+650 and PKS 2155–304

open access: yesThe Astrophysical Journal Letters
The high-energy-peaked BL Lacertae objects (HBLs) are the main targets of the Imaging X-ray Polarimetry Explorer (IXPE) for investigating the mechanisms of radiation and particle acceleration in jets. In this Letter, we report the first IXPE observations
Xin-Ke Hu   +7 more
doaj   +1 more source

Active Galactic Nuclei in the Extreme Ultraviolet [PDF]

open access: yesInternational Astronomical Union Colloquium, 1995
EUV observations could provide valuable and unique information about the nature of active galactic nuclei. I discuss their potential usefulness and review some of the main results obtained so far with the ROSAT WFC and the EUVE instruments. About three dozen sources, mostly Seyfert galaxies and BL Lacertae objects, have already been identified, and ...
openaire   +4 more sources

Clinical application of single‐cell RNA sequencing in disease and therapy

open access: yesClinical and Translational Medicine, Volume 15, Issue 11, November 2025.
This review provides a comprehensive overview of the application of scRNA‐seq in revisiting the somatic cell evolutions in human diseases, as well as in biomarker discovery and drug development. Abstract Background The emergence of single‐cell RNA sequencing (scRNA‐seq) technology has revolutionized our capacity to study cell functions in complex ...
Aisha Shigna Nadukkandy   +3 more
wiley   +1 more source

A Long-term Study of Mrk 50: Appearance and Disappearance of Soft Excess

open access: yesThe Astrophysical Journal
We present an extensive temporal and spectral study of the Seyfert 1 AGN Mrk 50 using 15 yr (2007–2022) of multiwavelength observations from XMM-Newton, Swift, and NuSTAR for the first time.
Narendranath Layek   +3 more
doaj   +1 more source

ATAC‐seq in Emerging Model Organisms: Challenges and Strategies

open access: yesJournal of Experimental Zoology Part B: Molecular and Developmental Evolution, Volume 344, Issue 7, Page 394-414, November 2025.
Principle of ATAC‐seq (left), overview of arthropod species with published ATAC‐seq data (middle), summary of experimental design (right). ABSTRACT The Assay for Transposase‐Accessible Chromatin with sequencing (ATAC‐seq) is a versatile and widely utilized method for identifying potential regulatory regions, such as promoters and enhancers, within a ...
Duğçar Ebrar Erdoğan   +13 more
wiley   +1 more source

Home - About - Disclaimer - Privacy