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We examine the absorption of cosmic microwave background (CMB) photons by formaldehyde (H2CO) over cosmic time. The K-doublet rotational transitions of H2CO become "refrigerated" - their excitation temperatures are driven below the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jeremy Darling , Benjamin Zeiger

Context: As more and more data are collected by cosmic ray experiments such as the Pierre Auger Observatory and Telescope Array (TA), the search for the sources of the Ultra High Energy Cosmic Rays (UHECR) continues. Already we have some…

High Energy Astrophysical Phenomena · Physics 2011-12-06 Laurentiu I. Caramete , Oana Tascau , Peter L. Biermann , Todor Stanev

In a concordant $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model, large-angle Cosmic Microwave Background (CMB) temperature anisotropy due to linear perturbations in the local universe is not negligible. We explore a possible role of an…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-09 Kaiki Taro Inoue

Recent satellite observations have revealed significant anisotropy in the cosmic microwave background (CMB) radiation, a phenomenon that had previously been detected but received limited attention due to its subtlety. With the advent of…

General Relativity and Quantum Cosmology · Physics 2025-02-10 S. Davood Sadatian , Amir Sabouri , Zahra Davari

We constrain the deviation of adiabatic evolution of the Universe using the data on the Cosmic Microwave Background (CMB) temperature anisotropies measured by the {\it Planck} satellite and a sample of 481 X-ray selected clusters with…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-31 I. de Martino , R. Génova-Santos , F. Atrio-Barandela , H. Ebeling , A. Kashlinsky , D. Kocevski , C. J. A. P. Martins

Some studies suggested that a correlation between locations of BL Lacertae objects (BL Lacs) and the arrival directions of the ultrahigh energy cosmic rays (UHECRs) exists. Especially by assuming the primary particles charged +1 and using a…

Astrophysics · Physics 2007-05-23 Zhen Cao , Ben Zhong Dai , Jian Ping Yang , Li Zhang

The IceCube Neutrino Observatory has recently found compelling evidence for a particular blazar producing high-energy neutrinos and $\mathrm{PeV}$ cosmic rays, however the sources of cosmic rays above several $\mathrm{EeV}$ remain…

High Energy Astrophysical Phenomena · Physics 2019-05-27 Lisa Schumacher

Current estimates of number counts of radio sources in the frequency range where the most sensitive Cosmic Microwave Background (CMB) experiments are carried out significantly under-represent sources with strongly inverted spectra. Hot…

Astrophysics · Physics 2009-10-31 Rosalba Perna , Tiziana Di Matteo

Gamma-ray bursts (GRBs) are proposed as candidate sources of ultra-high energy cosmic rays (UHECRs). We study the possibility that the PeV neutrinos recently observed by IceCube are produced by GRB cosmic rays interacting with the…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Zi-Yi Wang , Xiang-Yu Wang , Jun-Feng Wang

With the publicly available astrophysical simulation framework for propagating extraterrestrial UHE particles, CRPropa 3, it is now possible to study realistic UHECR source scenarios including deflections in Galactic and extragalactic…

High Energy Astrophysical Phenomena · Physics 2018-02-14 Arjen van Vliet , Rafael Alves Batista , Günter Sigl

In the last years a general consensus has emerged on the use of ultra-high energy cosmic rays (UHECR) data as a powerful probe of the validity of special relativity. This applies in particular to the propagation of cosmic rays from their…

High Energy Astrophysical Phenomena · Physics 2015-09-04 D. Boncioli , A. di Matteo , F. Salamida , R. Aloisio , P. Blasi , P. L. Ghia , A. F. Grillo , S. Petrera , T. Pierog

We discuss the differences induced by the assumed composition of extragalactic sources on the predicted UHECR spectrum and the energy evolution of $<X_{\max}>$, i.e. the mean value of the atmospheric depth at the cosmic-ray air shower…

Astrophysics · Physics 2009-11-13 D. Allard , A. V. Olinto , E. Parizot

We revisit the neutrino and ultra high-energy cosmic ray (UHECR) production from gamma-ray bursts (GRBs) with time-dependent simulations for the proton-induced cascades. This method can generate self-consistent photon, neutrino and escaped…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Katsuaki Asano , Peter Meszaros

We study the cosmic microwave background (CMB) anisotropy due to spherically symmetric nonlinear structures in flat universes with dust and a cosmological constant. By modeling a time-evolving spherical compensated void/lump by…

Astrophysics · Physics 2009-02-20 Nobuyuki Sakai , Kaiki Taro Inoue

The cosmic microwave background temperature is a cornerstone astrophysical observable. Its present value is tightly constrained, but its redshift dependence, which can now be determined until redshift $z\sim6.34$, is also an important probe…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 L. Gelo , C. J. A. P. Martins , N. Quevedo , A. M. M. Vieira

The interpretation of the ultra-high-energy cosmic ray spectrum (UHECRs) and composition suggests a suppression of the flux below $\sim$1 EeV, as observed by the Pierre Auger Observatory and Telescope Array. A natural explanation for this…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Alessandro Cermenati , Roberto Aloisio , Pasquale Blasi , Carmelo Evoli

We present the results of a new estimation of the photodisintegration and propagation of ultrahigh energy cosmic ray (UHCR) nuclei in intergalactic space. The critical interactions for photodisintegration and energy loss of UHCR nuclei…

Astrophysics · Physics 2010-11-30 F. W. Stecker

It is generally assumed that for energy injection before recombination, all of the injected energy is dissipated as heat in the baryon-photon plasma, giving rise to the $y$-type, $i$-type, and $\mu$-type distortions in the CMB spectrum. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-25 Sandeep Kumar Acharya , Rishi Khatri

Gamma-ray bursts (GRBs) are one of the candidates of ultra-high-energy (around 10^18.5 eV) cosmic-ray (UHECR) sources. We investigate high-energy cosmic-ray acceleration including heavy nuclei in GRBs by using Geant 4, and discuss its…

Astrophysics · Physics 2015-04-23 Kohta Murase , Kunihito Ioka , Shigehiro Nagataki , Takashi Nakamura

Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Henkel , K. M. Menten , M. T. Murphy , N. Jethava , V. V. Flambaum , J. A. Braatz , S. Muller , J. Ott , R. Q. Mao
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