Results 91 to 100 of about 37,389 (216)

The Peculiar Variable X-Ray Spectrum of the Active Galactic Nucleus PKS 2005–489

The Astrophysical Journal, 2023
PKS 2005−489 is a well-known, bright southern BL Lac object that has been detected up to TeV energies. In a low-flux state it exhibits the expected multiwavelength double-peaked spectrum in the radio− γ -ray band.
Owen Chase, Felicia McBride, Andrea Gokus, Matteo Lucchini, Haocheng Zhang, Roopesh Ojha, Derek B. Fox   +6 more
doaj   +1 more source

Calorimetry of Active Galactic Nucleus jets: testing plasma composition in Cygnus A

, 2012
We examine plasma composition of jets in active galactic nuclei through the comparison of the total pressure ($P$) with partial pressures of electrons and protons in a cocoon.
Amato, Arnaud, Asano, Asano, Atoyan, Bach, Bach, Blandford, Blundell, Bîrzan, Cavagnolo, Croston, De Young, Dermer, F. Takahara, Garrington, Georganopoulos, Ghisellini, Godfrey, Hardcastle, Harris, Hirotani, Hirotani, Hirotani, Homan, Ichimaru, Isobe, Isobe, Ito, Iwamoto, Iwamoto, Kataoka, Kellermann, Kino, Kirk, Krichbaum, Lazio, Lister, Lister, M. Kino, McKinney, Mehta, Mizuta, N. Kawakatu, Perlman, Quataert, Rachen, Rafferty, Reynolds, Ruszkowski, Scheuer, Sikora, Sironi, Smith, Spitkovsky, Stawarz, Tashiro, Tashiro, Thompson, Uchiyama, Watanabe, Wilson, Wilson, Yaji, Yamasaki   +64 more
core   +1 more source

Discovery of a dual active galactic nucleus with ∼8 kpc separation [PDF]

Monthly Notices of the Royal Astronomical Society: Letters, 2017
Abstract Targeted searches for dual active galactic nuclei (AGNs), with separations 1–10 kpc, have yielded relatively few successes. A recent pilot survey by Satyapal et al. has demonstrated that mid-infrared (mid-IR) pre-selection has the potential to significantly improve the success rate for dual AGN confirmation in late stage galaxy ...
Ellison, S., Secrest, N., Mendel, J., Satyapal, S., Simard, L.   +4 more
openaire   +3 more sources

A Low‐Power Radioisotope XRF Spectrometer for Detection of Light Elements on Planetary Missions

X-Ray Spectrometry, EarlyView.
ABSTRACT Current X‐ray spectrometers for in situ geochemical analysis on planetary missions typically rely either on X‐ray tubes, which demand electrical power and add mass and thermal complexity, or on alpha particle X‐ray spectrometers (APXS) that use rare 244Cm$$ {}^{244}\mathrm{Cm} $$ sources, and come with severe concerns on radiation safety and ...
Leandro Silveri, Artem Knyazev, Hashem Alaidaros, Maryam Manzoor Amanullah, Zach Ioannou, Tengiz Ibrayev, Danish Khan, Sara Leardini, Laura Manenti, Simi Maria Emilia Mangani, Safa Naseem, Sandhya Sharma, Sara Trevisan, Alia Zino, Francesco Arneodo   +14 more
wiley   +1 more source

Tracking X-Ray Variability in Next-generation EHT Low-luminosity Active Galactic Nucleus Targets

The Astrophysical Journal
We present a 5 month NICER X-ray monitoring campaign for two low-luminosity active galactic nuclei (LLAGNs)—NGC 4594 and IC 1459—with complementary Swift and NuSTAR observations.
Nicole M. Ford, Michael Nowak, Venkatessh Ramakrishnan, Daryl Haggard, Kristen Dage, Dhanya G. Nair, Chi-kwan Chan   +6 more
doaj   +1 more source

The nature of orbits in a prolate elliptical galaxy model with a bulge and a dense nucleus

, 2011
We study the transition from regular to chaotic motion in a prolate elliptical galaxy dynamical model with a bulge and a dense nucleus. Our numerical investigation shows that stars with angular momentum Lz less than or equal to a critical value Lzc ...
Caranicolas, Nicolaos D., Zotos, Euaggelos E.   +1 more
core   +1 more source

‘Mere Amateurs’? Elementary Teachers and the Making of Scientific Authority in the British Child Study Movement

History, EarlyView.
Abstract This article offers new perspectives on the relationship between elementary teaching, scientific expertise and the professionalization of the human sciences. Previous scholarship has demonstrated the ready existence of ‘amateur’ science societies in the nineteenth century where cross‐class exchanges were common.
Julia Gustavsson
wiley   +1 more source

Discovery of a Gas-enshrouded Broad-line Active Galactic Nucleus at z ∼ 7

The Astrophysical Journal Letters
The Ly α absorption profile in star-forming galaxies serves as a powerful tracer of the extended, dense neutral hydrogen in their surroundings during the Epoch of Reionization (EoR).
Qianqiao Zhou, Xin Wang, Hang Zhou, Emanuele Daddi, Luis C. Ho, Shengzhe Wang, Ruancun Li, Zuyi Chen, Cheng Cheng, Xihan Ji, Yuxuan Pang, Mengting Ju   +11 more
doaj   +1 more source

HST and LAMOST discover a dual active galactic nucleus in J0038+4128

, 2014
We report the discovery of a kiloparsec-scale dual active galactic nucleus (AGN) in J0038+4128. From the Hubble Space Telescope (HST) Wide Field Planetary Camera (WFPC2) images, we find two optical nuclei with a projection separation of 4.7 kpc (3.44 ...
Hou, Y. -H., Huang, Y., Huo, Z. -Y., Jin, G., Liu, X. -W., Xiang, M. -S., Yuan, H. -B., Zhang, Y., Zhou, X. -L.   +8 more
core   +1 more source

Toll‐like receptor 4 mediates lipopolysaccharide‐induced emesis

British Journal of Pharmacology, EarlyView.
Background and Purpose Lipopolysaccharide (LPS) induces inflammation and sepsis through Toll‐like receptor 4 (TLR4) activation. Common laboratory animals do not exhibit emesis, but administration of LPS in piglets, cats, and dogs induces emesis via peripheral mechanisms.
Luping Liu, Zengbing Lu, Julia Yuen Hang Liu, Man Piu Ngan, Kai‐Hei Tse, John Anthony Rudd   +5 more
wiley   +1 more source