The Redshift-Distance Relation. 111. Photometry and the Hubble Diagram for Radio Sources and the Possible Turn-On Time for QSOS

1972 ◽  
Vol 178 ◽  
pp. 25 ◽  
Author(s):  
Allan Sandage
Keyword(s):  
Radio Sources ◽  
Hubble Diagram ◽  
Turn On ◽  
Distance Relation

scholarly journals MODIFICATIONS OF THE HUBBLE LAW IN SCALE-DEPENDENT COSMOLOGY

1996 ◽  
Vol 11 (31) ◽  
pp. 5519-5539 ◽  
Author(s):  
C.W. KIM ◽  
J. SONG ◽  
T.H. LEE
Keyword(s):  
Cosmological Model ◽  
Mass Density ◽  
Numerical Results ◽  
Luminosity Distance ◽  
Hubble Diagram ◽  
Inhomogeneous Universe ◽  
Open Universe ◽  
The Universe ◽  
Distance Relation ◽  
Increasing Function

We study some observational consequences of a recently proposed scale-dependent cosmological model for an inhomogeneous universe. In this model the universe is pictured as being inside a highly dense and rapidly expanding shell with the underdense center. For nearby objects (z≪1), the linear Hubble diagram is shown to remain valid even in this model, which has been demonstrated both analytically and numerically. For large z, we present some numerical results of the redshift luminosity distance relation and the behavior of the mass density as a function of the redshift. It is shown that the Hubble diagram in this model for a locally open universe (Ω(t0, r~0)=0.1) resembles that of the flat Friedmann cosmology. This implies that the study of the Hubble diagram cannot uniquely determine the value of q0 or Ω0. The model also accounts for the fact that Ω0 is an increasing function of the redshift.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

The combined Herstmonceux Cambridge Program of optical positions of radio sources

1978 ◽  
Vol 48 ◽  
pp. 155-166 ◽  
Author(s):  
A. N. Argue ◽  
E. D. Clements ◽  
G. M. Harvey ◽  
C. A. Murray
Keyword(s):  
Standard Error ◽  
Unit Weight ◽  
Radio Sources

SummaryAGK3-based optical positions are presented for 38 counterparts of radio sources selected from the catalogue of Elsmore & Ryle. The measurements were made from plates taken with the 13-inch Astrograph, the 26-inch refractor and the 2.5 m (INT) reflector at Herstmonceux, and the 17-inch Schmidt at Cambridge. The standard error for a mean position of unit weight is 0”.11, and the weights range from 3.0 for the brightest sources to 0.5 for the faintest. Comparison with the radio positions shows no significant differences. The effects of applying the Brorfelde corrections to AGK3 are discussed.

Ubiquinone-BODIPY nanoparticles for tumor redox-responsive fluorescence imaging and photodynamic activity

2021 ◽  
Author(s):  
Byunghee Hwang ◽  
Tae-Il Kim ◽  
Hyunjin Kim ◽  
Sungjin Jeon ◽  
Yongdoo Choi ◽  
...  
Keyword(s):  
Fluorescence Imaging ◽  
Selective Activation ◽  
Turn On ◽  
Intracellular Environment ◽  
Redox Responsive ◽  
Photodynamic Activity

A ubiquinone-BODIPY photosensitizer self-assembles into nanoparticles (PS-Q-NPs) and undergoes selective activation within the highly reductive intracellular environment of tumors, resulting in “turn-on” fluorescence and photosensitizing activities.

After "After the Turn On, What?", What?

1973 ◽  
Vol 18 (12) ◽  
pp. 626-627
Author(s):  
EDWARD A. JACOBSON
Keyword(s):  
Turn On
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