Results 71 to 80 of about 8,408 (187)

Lyman-alpha Cooling Emission from Galaxy Formation

, 2010
Recent studies have shown that galaxies accrete most of their baryons via the cold mode, from streams with temperatures T~10^4-10^5 K. At these temperatures, the streams should radiate primarily in the Lya line and have therefore been proposed as a model to power the extended, high-redshift objects known as Lya blobs and other high-redshift Lya sources.
Faucher-Giguere, C. -A., Keres, D., Dijkstra, M., Hernquist, L., Zaldarriaga, M.   +4 more
openaire   +2 more sources

MIDIS: JWST NIRCam and MIRI Unveil the Stellar Population Properties of Lyα Emitters and Lyman-break Galaxies at z ≃ 3–7

The Astrophysical Journal
We study the stellar population properties of 182 spectroscopically confirmed (MUSE/VLT) Ly α emitters (LAEs) and 450 photometrically selected Lyman-break galaxies (LBGs) at z = 2.8–6.7 in the Hubble Extreme Deep Field.
Edoardo Iani, Karina I. Caputi, Pierluigi Rinaldi, Marianna Annunziatella, Leindert A. Boogaard, Göran Östlin, Luca Costantin, Steven Gillman, Pablo G. Pérez-González, Luis Colina, Thomas R. Greve, Gillian Wright, Almudena Alonso-Herrero, Javier Álvarez-Márquez, Arjan Bik, Sarah E. I. Bosman, Alejandro Crespo Gómez, Andreas Eckart, Jens Hjorth, Iris Jermann, Alvaro Labiano, Danial Langeroodi, Jens Melinder, Thibaud Moutard, Florian Peißker, John P. Pye, Tuomo V. Tikkanen, Paul P. van der Werf, Fabian Walter, Thomas K. Henning, Pierre-Olivier Lagage, Ewine F. van Dishoeck   +31 more
doaj   +1 more source

Comparison of Interannual Oscillations in the F, E, and D‐Region Ionosphere Using Longterm Ground‐Based Measurements

Journal of Geophysical Research: Space Physics, Volume 130, Issue 5, May 2025.
Abstract This comprehensive study focuses on interannual oscillations from 1 to 25 years in the F, E, and D region ionosphere. By leveraging longterm (1960–2018) continuous ground‐based ionosonde and phase height measurements in northern Germany, we have identified the peak periods and temporal variations of these oscillations using advanced analysis ...
Mani Sivakandan, Dieter H. W. Peters, Jens Mielich, Toralf Renkwitz, Ralph Latteck, Jorge L. Chau   +5 more
wiley   +1 more source

Ionospheric D Region: Characteristics Near Dawn and Dusk

Journal of Geophysical Research: Space Physics, Volume 130, Issue 4, April 2025.
Abstract The characteristics of very low frequency (VLF) radio wave propagation in the Earth‐ionosphere waveguide are determined particularly through dawn and dusk using phase and amplitude measurements of man‐made signals propagating below the ionospheric D region. For the first time variations of “Wait” height and sharpness parameters, H' and β, have
Neil R. Thomson, Mark A. Clilverd, Craig J. Rodger   +2 more
wiley   +1 more source

Correlation Between the Delay and Rise Time of VLF/LF Amplitudes During 20 Solar X‐Ray Flares Observed in February 2014 at Mid‐Latitude

Radio Science, Volume 60, Issue 4, April 2025.
Abstract During daylight hours, the concentration of electrons in the ionosphere can be amplified by solar flares, which may subsequently influence the propagation of radio waves. Previous research on Very Low Frequency (VLF) signals focused on X‐class and M‐class flares.
Y. Liu, M. Füllekrug
wiley   +1 more source

Impact of Sudden Stratospheric Warming and Elevated Stratopause Events on the Very Low Frequency Radio Signal

Journal of Geophysical Research: Space Physics, Volume 130, Issue 3, March 2025.
Abstract Sudden Stratospheric Warmings (SSW) and Elevated Stratopause (ES) events are mid‐to‐high latitudinal, atmospheric wave‐driven phenomena leading to significant changes in wind, temperatures, and vertical mass transport, especially at stratospheric and mesospheric altitudes.
H. Schneider, V. Wendt, D. Banyś, M. Hansen, M. Clilverd, P. T. Verronen   +5 more
wiley   +1 more source

Observational Signatures of Lyman Alpha Emission from Early Galaxy Formation. [PDF]

Proceedings of Cosmic Radiation Fields: Sources in the early Universe — PoS(CRF 2010), 2011
6 pages, 4 figures; conference proceedings from "Cosmic Radiation Fields: Sources in the early Universe", 2010, Hamburg ...
openaire   +3 more sources

A High Rate of Foreground Contaminants toward High-redshift Galaxies Resolved by JWST

The Astrophysical Journal
We present a study of high-redshift Ly α emitters (LAEs) with multiple components using the Hubble Space Telescope and JWST. High-redshift galaxies are mostly point-like objects on ground-based images, but they often exhibit multiple components in higher
Weiyang Liu, Linhua Jiang
doaj   +1 more source

Das zirkumgalaktische Medium

Physik in unserer Zeit, Volume 56, Issue 1, Page 30-37, January 2025.
Galaxien wie die Milchstraße sind umhüllt von einem gigantischen Kokon aus diffusem Gas. Aktuelle Forschungsergebnisse belegen, dass dieses zirkumgalakische Medium eine entscheidende Rolle für die Entstehung und Entwicklung von Galaxien spielt. Zusammenfassung Als zirkumgalaktisches Medium bezeichnet man die gasförmigen Hüllen von Galaxien, die sich ...
Philipp Richter
wiley   +1 more source

Lyman alpha emission in high-redshift galaxies

, 2007
A significant fraction of the high-redshift galaxies show strong Lyman emission lines. For redshifts z>5, most known galaxies belong to this class. However, so far not much is known about the physical structure and nature of these objects. Our aim is to analyse the Lyman alpha emission in a sample of high-redshift UV-continuum selected galaxies and ...
Tapken, C., Appenzeller, I., Noll, S., Richling, S., Heidt, J., Meinkoehn, E., Mehlert, D.   +6 more
openaire   +2 more sources