Results 101 to 110 of about 37,989 (204)

Probing Chemical Enrichment in Extremely Metal-poor Galaxies

The Astrophysical Journal
The chemical composition of galaxies offers vital insights into their formation and evolution. In particular, the relationship between helium abundance (He/H) and metallicity serves as a key diagnostic for estimating the primordial helium yield from Big ...
Keita Fukushima, Kentaro Nagamine, Akinori Matsumoto, Yuki Isobe, Masami Ouchi, Takayuki R. Saitoh, Yutaka Hirai   +6 more
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Primordial Axion Stars and Galaxy Halos Formation

Universe
Primordial axion stars, hypothetical stars formed from axions, could play an essential role in forming galaxy halos. These stars could have originated in the early universe shortly after the Big Bang. We show that while “normal” axions coalesce into a gravitationally bound Bose-Einstein condensate, forming a dense object - an axion star, the ultralight
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Galaxy Formation from the Primordial Black Holes [PDF]

EPJ Web of Conferences, 2017
Supermassive black hole (SMBH) of size MBH = 106-10M⊙ is common in the Universe and it defines the center of the galaxy. A galaxy and the SMBH are generally thought to have co-evolved. However, the SMBH cannot evolve so fast as commonly observed even at redshift z > 6.
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Forecasting local primordial non-Gaussianities from UNIONS Lyman-break galaxies and Planck CMB lensing

Astronomy & Astrophysics
Context. Local primordial non-Gaussianities, characterized by the parameter fNLloc f NL loc $ f_{\mathrm{NL}}^{\mathrm{loc}} $ , provide a powerful window into the physics of inflation.
Payerne Constantin, d’Assignies William, Yèche Christophe, Hildebrandt Hendrik, Lang Dustin, de Boer Thomas, Fabbro Sébastien   +6 more
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Massive Black Hole Seed Formation in Strong X-Ray Environments at High Redshift

The Astrophysical Journal
Direct collapse of pristine gas in early galaxies is a promising pathway for forming supermassive black holes (SMBHs) powering active galactic nuclei at the Epoch of Reionization (EoR). This seeding mechanism requires suppression of molecular hydrogen (H
Kazutaka Kimura, Kohei Inayoshi, Kazuyuki Omukai   +2 more
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Parity violation in galaxy shapes: Primordial non-Gaussianity

Physical Review D
We present a comprehensive study of galaxy intrinsic alignment (IA) as a probe of parity-violating primordial non-Gaussianity (PNG). Within the effective field theory (EFT) framework, we show that the parity-odd IA power spectrum is sensitive to the collapsed limit of the parity-odd primordial trispectrum. For a
Toshiki Kurita, Drew Jamieson, Eiichiro Komatsu, Fabian Schmidt   +3 more
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Revealing the Origins of Galactic Globular Clusters via their Mg–Al Abundances

The Astrophysical Journal Letters
Many Galactic globular clusters (GCs) originated in diverse host galaxies before being subsequently incorporated into the Milky Way through hierarchical galaxy assembly. Identifying their origins is crucial for revealing galaxy properties at early times.
Shihui Lin, Baitian Tang, Genghao Liu, José G. Fernández-Trincado, Douglas Geisler, Guy Worthey, Dante Minniti   +6 more
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METALS IN THE ICM: WITNESSES OF CLUSTER FORMATION AND EVOLUTION

Acta Polytechnica, 2013
The baryonic composition of galaxy clusters and groups is dominated by a hot, X-ray emitting Intra-Cluster Medium (ICM). The mean metallicity of the ICM has been found to be roughly 0.3 ÷ 0.5 times the solar value, therefore a large fraction of this gas ...
Lorenzo Lovisari, Tatiana F. Laganá, Katharina Borm, Gerrit Schellenberger, Thomas H. Reiprich   +4 more
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Accelerating Massive Galaxy Formation with Primordial Black Hole Seed Nuclei

The Astronomical Journal
If massive primordial black holes (PBHs) exist and constitute a fraction of the dark matter, they can dramatically catalyze galaxy formation. By acting as pre-existing, high-density seeds, they can shorten the galaxy assembly time to as little as 100 Myr
Jeremy Mould
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Non-Gaussianity from Large-Scale Structure Surveys

Advances in Astronomy, 2010
With the advent of galaxy surveys which provide large samples of galaxies or galaxy clusters over a volume comparable to the horizon size (SDSS-III, HETDEX, Euclid, JDEM, LSST, Pan-STARRS, CIP, etc.) or mass-selected large cluster samples over a large ...
Licia Verde
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