Results 71 to 80 of about 2,186 (186)

The nature of high-redshift galaxies [PDF]

Physics Reports, 1998
Abstract Using semi-analytic models of galaxy formation, we investigate the properties of z∼3 galaxies and compare them with the observed population of Lyman-break galaxies (LBGs). In addition to the usual quiescent mode of star formation, we introduce a physical model for starbursts triggered by galaxy–galaxy interactions.
Joel R. Primack, Rachel S. Somerville, S.M. Faber, Risa H. Wechsler   +3 more
openaire   +1 more source

Two Micron‐Size Dark Dimensions

Fortschritte der Physik, Volume 73, Issue 8, August 2025.
Abstract Two extra dimensions of micron scale might simultaneously address the gauge and cosmological hierarchy problems. In this paper various observational bounds in scenarios with one and two large extra dimensions are examined, to see if they are compatible with the micron scale.
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lüst   +2 more
wiley   +1 more source

The AURORA Survey: High-redshift Empirical Metallicity Calibrations from Electron Temperature Measurements at z = 2–10

The Astrophysical Journal
We present detections of auroral emission lines of [O iii ], [O ii ], [S iii ], and [S ii ] in deep JWST/NIRSpec spectroscopy for 41 star-forming galaxies at z  = 1.4–7.2 from the AURORA survey.
Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Danielle A. Berg, Ali Ahmad Khostovan, Rychard J. Bouwens, Gabriel Brammer, Adam C. Carnall, Fergus Cullen, Romeel Davé, James S. Dunlop, Richard S. Ellis, N. M. Förster Schreiber, Steven R. Furlanetto, Karl Glazebrook, Garth D. Illingworth, Tucker Jones, Mariska Kriek, Derek J. McLeod, Ross J. McLure, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, Daniel Schaerer, Daniel P. Stark, Charles C. Steidel, Mengtao Tang, Leonardo Clarke, Callum T. Donnan, Emily Kehoe   +31 more
doaj   +1 more source

Photometric Redshifts and High‐Redshift Galaxies [PDF]

Publications of the Astronomical Society of the Pacific, 1999
The Workshop "Photometric Redshifts and High‐Redshift Galaxies" was held at the Observatories of the Carnegie Institution of Washington, in Pasadena, California, on 1999 April 28–30. The 70 participants were greeted with atypically cool, overcast weather, but this did not cloud or dampen the discussions.
openaire   +2 more sources

Redshift‐Agnostic Machine Learning Classification: Unveiling Peak Performance in Galaxy, Star, and Quasar Classification (Using SDSS DR17)

Astronomische Nachrichten, Volume 346, Issue 5, June 2025.
ABSTRACT Classification of galaxies, stars, and quasars using spectral data is fundamental to astronomy, but often relies heavily on redshift. This study evaluates the performance of 10 machine learning algorithms on SDSS data to classify these objects, with a particular focus on scenarios where redshift information is unavailable.
Debashis Chatterjee, Prithwish Ghosh
wiley   +1 more source

Tracing nitrogen enrichment across cosmic time with JWST

Astronomy & Astrophysics
We present a comprehensive analysis of the nitrogen-to-oxygen (N/O) abundance ratio in a sample of ∼660 star-forming galaxies at redshift z ∼ 1 − 6, with a median redshift of ⟨z⟩ = 3.0, using deep JWST/NIRSpec spectroscopy. Leveraging detections of faint
Cataldi E., Belfiore F., Curti M., Moreschini B., Marconi A., Maiolino R., Feltre A., Ginolfi M., Mannucci F., Cresci G., Ji X., Amiri A., Arnaboldi M., Bertola E., Bracci C., Ceci M., Chakraborty A., Cullen F., D’Amato Q., Kobayashi C., Lamperti I., Marconcini C., Scialpi M., Ulivi L., Zanchettin M. V.   +24 more
doaj   +1 more source

High‐Redshift Galaxy Outflows and the Formation of Dwarf Galaxies

The Astrophysical Journal, 2001
15 pages, 9 figures, accepted to the Astrophysical ...
Scannapieco, Evan, Thacker, Robert J., Davis, Marc   +2 more
openaire   +2 more sources

Lactea: Web‐Based Spectrum‐Preserving Multi‐Resolution Visualization of the GAIA Star Catalog

Computer Graphics Forum, Volume 44, Issue 3, June 2025.
Abstract The explosion of data in astronomy has resulted in an era of unprecedented opportunities for discovery. The GAIA mission's catalog, containing a large number of light sources (mostly stars) with several parameters such as sky position and proper motion, is playing a significant role in advancing astronomy research and has been crucial in ...
Reem Alghamdi, Markus Hadwiger, Guido Reina, Alberto Jaspe‐Villanueva   +3 more
wiley   +1 more source

Dark Energy From the Gravitational Wave Background With Scalar Field Dark Matter

Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT Recent observational results, such as those from pulsar timing arrays (PTA), suggest a low‐frequency Gravitational Wave Background (GWB) permeates our universe. This opens the possibility that gravitational waves could span a broader spectrum, potentially impacting cosmological scales.
Edwin L. Pérez‐Ochoa, Tonatiuh Matos
wiley   +1 more source

The AGORA High-resolution Galaxy Simulations Comparison Project. X. Formation and Evolution of Galaxies at the High-redshift Frontier

The Astrophysical Journal
Recent observations from the James Webb Space Telescope have revealed unexpectedly luminous galaxies, exhibiting stellar masses and luminosities significantly higher than predicted by theoretical models at Cosmic Dawn.
Hyeonyong Kim, Ji-hoon Kim, Minyong Jung, Santi Roca-Fàbrega, Daniel Ceverino, Pablo Granizo, Kentaro Nagamine, Joel R. Primack, Héctor Velázquez, Kirk S. S. Barrow, Robert Feldmann, Keita Fukushima, Lucio Mayer, Boon Kiat Oh, Johnny W. Powell, Tom Abel, Oscar Agertz, Chaerin Jeong, Alessandro Lupi, Yuri Oku, Thomas R. Quinn, Yves Revaz, Ramón Rodríguez-Cardoso, Ikkoh Shimizu, Romain Teyssier, AGORA COLLABORATION   +25 more
doaj   +1 more source