Zhou You-yuan

A statisical analysis of quasars with resolved radio components: I. The redshift-magnitude relation

Abstract In this paper a statistical investigation is made on the redshift-magnituderelation for quasars with resolved radio components. The main results are: 1. 1. The largest linear distance D between the components is an important parameter which can be used in a “standard candle” classification. 2. 2. Regression equations among redshift, apparent magnitude and D have been established with high correlation coefficients and consequently, the redshifts of these quasars are likely to be cosmological in the main. 3. 3. The redshift-distance relation was found expressible in the form r ∞ z − 0.19z2, which departs markedly from Hubbles linear relation when z > 1. 4. 4. The new redshift-distance relation also gives a tighter redshift-magnitude relation for the radio galaxies than Hubbles relation does. 5. 5. The optical luminosity of a quasar is the smaller, the larger its value of D.

Statistical analysis of quasars with resolved radio components II. Variations of absolute visual magnitude, absolute radio magnitude and color index difference Q with linear separation of components, some associated evolution features

Abstract Using the standard candle classification by means of the linear distance D between the components, described in Paper I of this series, we have succeeded in uncovering, amongst quasars with maximum angular sizes, the statistical relations between visual magnitude and redshift, and between D and the absolute visual and radio magnitudes and the color index differences Q. These relations point to the following evolutionary features: 1. 1. The optical liminosity decreases with increasing D . dM ν dD = 10 m .6/ Mpc . 2. 2. The radio luminosity decreases with increasing D . dM 408−5000 dD = 9 m .17 Mpc . 3. 3. The color index difference Q decreases with increasing D . dQ dD = −1 m .55/ Mpc . 4. 4. The radio spectral type, as defined by the spectral index, shows no evolution in general. 5. 5. The optical radiation is mainly non-thermal, but the thermal component increases as the quasar evolves. 6. 6. The evolution time scales, as estimated from the variations in optical and radio luminosities and Q, have about the same value of 16 × 10 6 y. 7. 7. The above features are consistent with the view that QSOs evolve to galaxies. 8. 8. There is no apparent dependence of D on distance, i.e. no evidence that all QSOs were formed at the same epoch. This is contrary to the views of big bang cosmologies.

A clustering analysis of QSO candidates

Abstract By means of two-point correlation function, clustering analysis (precolation method) and multiplicity funciton, we analyse the clustering of quasars for two samples of quasar candidates, and find that there is no obvious difference between the results of the observed and Monte-Carlo samples, apart from a weak clustering on the scale of 100 Mpc in the former.

Concepts of Space and Time in Ancient China and in Modern Cosmology

Just as “the manifold forms of Greek philosophy contain in embryo, in the nascent state, almost all later modes of outlook on the world,”2 germs of modern science can also be found in ancient Chinese philosophy and scientific ideology. Concepts of time, space and the cosmos, which are important components of man’s view of nature, are no exception. Some ideas of time and space in modern physics and cosmology are also reflected in ancient Chinese works.

The time-dependent distribution of relativistic electrons in radio sources

The time-dependent distribution of relativistic electrons is very important to the discussion of light and the spectrum. This letter provides a general, time-dependent solution for the continuity equation of electron number density (CEEND). Several special solutions with the first Fermi acceleration and different injection patterns are obtained.

The spatial correlation function of cD Abell clusters

Abstract We calculated the spatial two-point correlation function of cD clusters in Abells statistical sample using estimated redshifts and found that positive correlation exists on all scales except around 70 Mpc and 170 Mpc (H0 = 100 km s−1 Mpc−1). In particular, positive correlation persists on the super large scale around 300 Mpc. This is particularly interesting in view of the known relationships among cD clusters, radio sources and superclusters.

The Evolution of Quasars Selected By Slitless Technique

After taking account of the selection effects in the identification of emission lines and choosing the sample within a narrow range of absolute magnitude, we can investigate the evolutionary function of quasars from their redshift distribution. From data given by slitless surveys with limiting apparent magnitude 19.5, we find that the evolutionary function takes form of ρ = ρo(l+z)6.5±1. The analysis has also showed that the observational redshift distribution of quasars is compatible with cosmological principle.

Statistical analyses of quasars with resolved radio components. III. Evolutionary properties of the sizes of components. IV. Evolutionary properties of radio polarization parameters

Abstract The sizes of 64 radio components of quasars have been determined using their angular diameters and redshifts. No significant correlation is found between their sizes and their mutual separation whether different initial luminosity ranges are considered separately or together. This result implies that the sizes of the components do not change much during the lifetime of quasars with a resolved radio structure. A statistical analysis has been made on the polarization properties of those quasars in which the Faraday depolarization is mainly responsible for the inverse relationship between the degree of polarization and the wavelengrh. Our results are: (1) There is no significant correlation between λ 1 2 and D ; there is, however, an obvious correlation between λ 1 2 2 d ∗ and D ∗ . (2) The statistical relation between m max and D shows that the random component of the magnetic field increases as the quasar evolves. (3) There is no evident evolutionary trend in the magnetic field given by minimizing the total energy. (4) The representation by a Gaussian of the Faraday depth distribution makes it obvious that the thermal electron density in the components decreases as the quasar evolves: n e = 2.24 × 10 −2 × 10 −0.071 D ∗