Extragalactic Radio Astronomy: Galaxy Classification, Active Galactic Nuclei, Superluminal Motion, Galaxy Clusters, and the Cosmic Microwave Background

2020 ◽  
pp. 269-321
Author(s):  
Thomas G. Pannuti
Keyword(s):  
Cosmic Microwave Background ◽  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Radio Astronomy ◽  
Galactic Nuclei ◽  
Microwave Background ◽  
Superluminal Motion ◽  
Galaxy Classification

MEASUREMENTS OF COSMIC RAYS AT THE HIGHEST ENERGIES WITH THE PIERRE AUGER OBSERVATORY

2011 ◽  
Vol 20 (05) ◽  
pp. 685-696
Author(s):  
◽  
DIEGO HARARI
Keyword(s):  
Cosmic Rays ◽  
Cosmic Microwave Background ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Active Galaxies ◽  
Pierre Auger Observatory ◽  
Matter Distribution ◽  
Microwave Background ◽  
Independent Evidence ◽  
Arrival Directions

Measurements with the Pierre Auger Observatory indicate with unprecedented statistics that the flux of cosmic rays is strongly suppressed above 4 × 1019 eV. The suppression is consistent with the prediction that cosmic rays with larger energies can only arrive from nearby sources due to their interaction with the cosmic microwave background, but could also be related to the efficiency of the acceleration processes at the sources. The Observatory has found independent evidence of the nearby extragalactic origin of cosmic rays with energy above ~6×1019 eV with a measurement of the fraction of arrival directions that correlate with the positions of active galactic nuclei within ~100 Mpc. This correlation does not identify active galaxies as the sites of origin, since their distribution traces the overall local matter distribution. We review recent measurements made with the Pierre Auger Observatory of the flux, anisotropy and composition of CRs.

scholarly journals IMPROVED LIMITS ON PHOTON VELOCITY OSCILLATIONS

2002 ◽  
Vol 17 (38) ◽  
pp. 2491-2496 ◽  
Author(s):  
ALESSANDRO DE ANGELIS ◽  
REYNALD PAIN
Keyword(s):  
Cosmic Microwave Background ◽  
Cosmological Constant ◽  
Active Galactic Nuclei ◽  
Gamma Rays ◽  
Optical Spectrum ◽  
Galactic Nuclei ◽  
Type Ia Supernovae ◽  
Microwave Background ◽  
Type Ia ◽  
Ia Supernovae

The mixing of the photon with a hypothetical sterile paraphotonic state would have consequences on the cosmological propagation of photons. The absence of distortions in the optical spectrum of distant Type Ia supernovae allows to extend by two orders of magnitude the previous limit on the Lorentz-violating parameter δ associated to the photon–paraphoton transition, extracted from the absence of distortions in the spectrum of the cosmic microwave background. The new limit is consistent with the interpretation of the dimming of distant Type Ia supernovae as a consequence of a nonzero cosmological constant. Observations of gamma-rays from active galactic nuclei allow to further extend the limit on δ.

scholarly journals Radio-loud active galactic nuclei at high redshifts and the cosmic microwave background

2014 ◽  
Vol 438 (3) ◽  
pp. 2694-2700 ◽  
Author(s):  
G. Ghisellini ◽  
A. Celotti ◽  
F. Tavecchio ◽  
F. Haardt ◽  
T. Sbarrato
Keyword(s):  
Cosmic Microwave Background ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Microwave Background

scholarly journals B2FH, the Cosmic Microwave Background and Cosmology

2008 ◽  
Vol 25 (1) ◽  
pp. 30-35
Author(s):  
G. Burbidge
Keyword(s):  
Cosmic Microwave Background ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Big Bang ◽  
Microwave Background ◽  
Personal View ◽  
Cyclic Universe ◽  
Fred Hoyle ◽  
The Universe ◽  
Made In

AbstractIn this talk I shall start by describing how we set about and carried out the work that led to the publication of Burbidge et al. (1957, hereafter B2FH). I then shall try and relate this work and the circumstances that surrounded it to the larger problem of the origin and formation of the universe. Here it is necessary to look back at the way that ideas developed and how, in many situations, astronomers went astray. Of course this is a personal view, though I very strongly believe that if he were still here, it is the approach that Fred Hoyle would take.I start by describing the problems originally encountered by Gamow and his associates in trying to decide where the helium was made. This leads me to a modern discussion of the origin of 2D, 3He, 4He and 7Li, originally described by B2FH as due to the x-process. While it is generally argued, following Gamow, Alpher, and Herman, that these isotopes were synthesised in a big bang I shall show that it is equally likely that these isotopes were made in active galactic nuclei, as was the cosmic microwave background (CMB), in a cyclic universe model. The key piece of observational evidence is that the amount of energy released in the conversion of hydrogen to helium in the universe is very close to the energy carried by the CMB, namely ∼4.5 × 10−13 erg cm−3.

scholarly journals Cosmological simulations of galaxy clusters with feedback from active galactic nuclei: profiles and scaling relations

2014 ◽  
Vol 445 (2) ◽  
pp. 1774-1796 ◽  
Author(s):  
Simon R. Pike ◽  
Scott T. Kay ◽  
Richard D. A. Newton ◽  
Peter A. Thomas ◽  
Adrian Jenkins
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Galactic Nuclei ◽  
Scaling Relations ◽  
Cosmological Simulations

scholarly journals AMIBA: FIRST-YEAR RESULTS FOR SUNYAEV-ZEL'DOVICH EFFECT

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1675-1686 ◽  
Author(s):  
JIUN-HUEI PROTY WU ◽  
TZI-HONG CHIUEH ◽  
CHI-WEI HUANG ◽  
YAO-WEI LIAO ◽  
FU-CHENG WANG ◽  
...  
Keyword(s):  
Cosmic Microwave Background ◽  
Galaxy Clusters ◽  
First Year ◽  
Microwave Background ◽  
Expansion Plan ◽  
Sunyaev Zel'dovich Effect ◽  
Systematic Effects ◽  
Science Operation

We discuss the observation, analysis, and results of the first-year science operation of AMiBA, an interferometric experiment designed to study cosmology via the measurement of Cosmic Microwave Background (CMB). In 2007, we successfully observed 6 galaxy clusters (z < 0.33) through the Sunyaev-Zel'dovich effect. AMiBA is the first CMB interferometer operating at 86–102 GHz, currently with 7 close-packed antennas of 60 cm in diameter giving a synthesized resolution of around 6 arcminutes. An observing strategy with on-off-source modulation is used to remove the effects from electronic offset and ground pickup. Formalism of the analysis is given and preliminary science results are summarized. Tests for systematic effects are also addressed. We also discuss the expansion plan.

scholarly journals THE COSMIC EVOLUTION OF ACTIVE GALACTIC NUCLEI IN GALAXY CLUSTERS

2009 ◽  
Vol 694 (2) ◽  
pp. 1309-1316 ◽  
Author(s):  
Audrey Galametz ◽  
Daniel Stern ◽  
Peter R. M. Eisenhardt ◽  
Mark Brodwin ◽  
Michael J. I. Brown ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Clusters ◽  
Galactic Nuclei ◽  
Cosmic Evolution
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