Results 71 to 80 of about 5,210 (169)

Searching the Non‐Accreting White Dwarf Population in eROSITA Data

Astronomische Nachrichten, Volume 346, Issue 1, January 2025.
ABSTRACT eROSITA is the soft X‐ray instrument aboard the Spectrum Roentgen Gamma (SRG) satellite that is most sensitive in the energy range between 0.2 and 2.3 keV. Between December 2019 and December 2021, eROSITA completed four all‐sky surveys, producing all‐sky X‐ray source lists and sky maps of unprecedented depth.
S. Friedrich, C. Maitra, K. Dennerl, A. Schwope, K. Werner, B. Stelzer   +5 more
wiley   +1 more source

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +9 more
wiley   +1 more source

Probing the dark energy with strong lensing by clusters of galaxies [PDF]

, 2002
Observations of clusters of galaxies that gravitationally lens faint background galaxies can probe the amount and the equation of state, ${w_{\rm X}}$, of the dark energy (quintessence) in the universe.
M. Sereno
semanticscholar   +1 more source

Flexible, Photonic Films of Surfactant‐Functionalized Cellulose Nanocrystals for Pressure and Humidity Sensing

Small Structures, Volume 5, Issue 7, July 2024.
Cellulose nanocrystals are abundant, biodegradable nanoparticles that can self‐assemble into a helical stacking that exhibits structural color. By adding a single surfactant, cellulose nanocrystals can be made compatible with apolar solvents, which are widely used for industrial coatings.
Diogo V. Saraiva, Steven N. Remiëns, Ethan I. L. Jull, Ivo R. Vermaire, Lisa Tran   +4 more
wiley   +1 more source

Chemical Evolution of the Universe and its Consequences for Gravitational‐Wave Astrophysics

Annalen der Physik, Volume 536, Issue 2, February 2024.
Population properties of double compact object mergers (especially binary black holes) are sensitive to the metallicity dependent cosmic star formation history. The uncertainty of this quantity cannot be ignored and makes the interpretation of current gravitational wave observations difficult.
Martyna Chruślińska
wiley   +1 more source

Cosmology with Gravitational Waves: A Review

Annalen der Physik, Volume 536, Issue 2, February 2024.
The review gives an overview of the most recent advances in gravitational‐wave (GWs) cosmology. After an in‐depth discussion of methodologies and tools for GW cosmology, it presents the latest results on measurements of standard cosmological parameters from the LIGO, Virgo, and KAGRA detections.
Simone Mastrogiovanni, Christos Karathanasis, Jonathan Gair, Gregory Ashton, Stefano Rinaldi, Hsiang‐Yu Huang, Gergely Dálya   +6 more
wiley   +1 more source

New Derivation of Redshift Distance Without Using Power Expansions. II. Additional Redshift Distances, Analyzing the Data of More Quasars, of Some SNIa, of the One Black Hole in Galaxy M87 as Well as a Newer Estimation of H₀

, 2022
In this part of the two-part series of essays, we first derive some equations for further physical redshift distances. We then analyze a catalog with 132,975 quasars, for which both the apparent magnitude m and the redshift z are given, in order to find the today’s value of the parameter β0 of the theory presented.
openaire   +2 more sources

Stratified learning: A general‐purpose statistical method for improved learning under covariate shift

Statistical Analysis and Data Mining: The ASA Data Science Journal, Volume 17, Issue 1, February 2024.
Abstract We propose a simple, statistically principled, and theoretically justified method to improve supervised learning when the training set is not representative, a situation known as covariate shift. We build upon a well‐established methodology in causal inference and show that the effects of covariate shift can be reduced or eliminated by ...
Maximilian Autenrieth, David A. van Dyk, Roberto Trotta, David C. Stenning   +3 more
wiley   +1 more source

Reinterpretation of Distant Galaxy Redshift and Cosmic Observable Distance Based on the Light Cosmology Theory

This work provides an approximate reinterpretation of the redshift–distance relationship of distant galaxies and the observable universe based on the light cosmology theory.Unlike standard cosmology (ΛCDM), the light cosmology theory assumes a universe expanding spherically at a constant speed of light, which imposes a natural upper limit on observable
openaire   +2 more sources

Extragalactic Science with the Orbiting Astronomical Satellite Investigating Stellar Systems (OASIS) Observatory. [PDF]

Space Sci Rev, 2023
Aalto S, Battersby C, Chin G, Hunt LK, Rigopoulou D, Stark AA, Viti S, Walker CK.   +7 more
europepmc   +1 more source