Results 91 to 100 of about 50,755 (263)

On the Properties of X-Ray Corona in Seyfert 1 Galaxies

open access: yesThe Astrophysical Journal
We carried out a uniform and systematic analysis of a sample of 112 nearby bright Seyfert 1 type active galactic nuclei, the observations of which were carried out by the Nuclear Spectroscopic Telescope Array between 2013 August and 2022 May.
Indrani Pal   +6 more
doaj   +1 more source

X-ray emission from active galactic nuclei [PDF]

open access: yes
It is often held that the X-ray emission from active galactic nuclei (AGN) arises from a region close to the central energy source. Thus X-ray observations may provide the best constraints on the central engine.
Mushotzky, R.
core   +1 more source

Penetrating the Deep Cover of Compton Thick Active Galactic Nuclei [PDF]

open access: yes, 2006
We analyze observations obtained with the Chandra X-ray Observatory of bright Compton thick active galactic nuclei (AGNs), those with column densities in excess of 1.5 x 10^{24} cm^{-2} along the lines of sight.
Antonucci R.   +20 more
core   +3 more sources

Millikelvin Intracellular Nanothermometry with Nanodiamonds

open access: yesAdvanced Science, Volume 12, Issue 45, December 4, 2025.
Nanothermometry in living cells is crucial for understanding heat diffusion and advancing cellular biology and drug discovery. Previous studies have reported controversial intracellular temperature variations. Using nanodiamond nanothermometry in macrophages, it is found that, in such experimental setting, apparent temperature changes are actually due ...
Maabur Sow   +26 more
wiley   +1 more source

NuSTAR Detection of an Absorption Feature in ESP 39607: Evidence for an Ultrafast Inflow?

open access: yesThe Astrophysical Journal
We report the serendipitous discovery of an absorption feature at 4.8 keV in the NuSTAR spectra of ESP 39607, a Seyfert 2 galaxy at z = 0.201, observed in 2023 May and 2024 August. The feature is detected in both observations with individual significance
Alessandro Peca   +6 more
doaj   +1 more source

X-ray variability observed with HEAO A-1 [PDF]

open access: yes
Results from the HEAO A-1 instrument which observed X-ray source variability over a wide range of accessible timescales are surveyed. The objects observed include quasars, BL Lacertae, and active galactic nuclei.
Friedman, H.
core   +1 more source

Review of Analytical Lithium Detection and Quantification Methods Along the Lithium Value Chain

open access: yesApplied Research, Volume 4, Issue 6, December 2025.
This article reviews a selection of suitable state‐of‐the‐art analytical methods for different scales of spatial resolution and detection of lithium for a variety of lithium‐bearing materials along the lithium value chain. The various materials differ greatly in terms of their lithium content by more than 5 orders of magnitude and also vary in their ...
Nico Kropp   +2 more
wiley   +1 more source

Identifying Compton-thick Active Galactic Nuclei with a Machine Learning Algorithm in Chandra Deep Field-South

open access: yesThe Astrophysical Journal
Compton-thick active galactic nuclei (CT-AGNs), which are defined by column density N _H ≥ 1.5 × 10 ^24 cm ^−2 , emit feeble X-ray radiation, even undetectable by X-ray instruments.
Rui Zhang   +9 more
doaj   +1 more source

The nature of the infrared counterpart of IGR J19140+0951

open access: yes, 2007
The INTEGRAL observatory has been (re-)discovering new X-ray sources since the beginning of nominal operations in early 2003. These sources include X-ray binaries, Active Galactic Nuclei, cataclysmic variables, etc.
Bird   +28 more
core   +1 more source

BASS. XLIX. Characterization of Highly Luminous and Obscured AGNs: Local X-Ray and [Ne V]λ3426 Emission in Comparison with the High-redshift Universe

open access: yesThe Astrophysical Journal
We present a detailed analysis of the most luminous and obscured active galactic nuclei (AGNs) detected in the ultra-hard X-ray band (14–195 kev) by the Swift/Burst Alert Telescope. Our sample comprises 21 X-ray luminous ( ${\mathrm{log}}\,{L}_{{\rm{X}}}/
Alessandro Peca   +23 more
doaj   +1 more source

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