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We have used the Sloan Digital Sky Survey (SDSS) data release 7 (DR7) and the 2MASS (Two Micron All Sky Survey) Redshift Survey (2MRS) $K_{s} \le11.75~\mbox{mag}$ data release to test for physical association of candidate companion quasars with putative parent galaxies by virtue of Karlsson periodicity in quasar redshifts. We conducted this analysis using the quasar family detection algorithm described in Fulton and Arp (Astrophys. J. 754:134, 2012) and used therein to analyze the 2dF Galaxy Redshift Survey (2dFGRS) and the 2dF Quasar Redshift Survey (2QZ). The SDSS and 2MRS data sets confirm the 2dF results and allow us to examine additional object behaviors also at high significance.

The effect of a cosmic time variation of Newton’s constant on galactic angular diameters, linear size, apparent magnitude, and surface brightness is investigated. The redshift scaling of the gravitational constant is proportional to the Hubble parameter, derived from the constancy of a moderate dimensionless ratio of fundamental constants, and manifested in galactic linear-size evolution. The latter is demonstrated by fitting the angular size–redshift relation to spectroscopically and photometrically selected samples of high-redshift rotators. The intrinsic luminosity evolution of the rotators and their magnitude–redshift and surface brightness–redshift relations are studied. The galactic luminosity scales with a power of the Hubble parameter, and the scaling exponent is inferred from a moderate dimensionless ratio involving the gravitational constant, the Galactic luminosity, and the velocity of the Galaxy in the microwave background. The fits are performed with a cosmic expansion factor derived from paleoplanetary surface temperatures. This expansion factor is tested by comparing the corresponding redshift evolution of the angular-size distance to the distance estimates of two samples of galaxy clusters.

The infrared properties of ULIRGs in samples from the Sloan Digital Sky Survey, 2dF Galaxy Redshift Survey and 6dF Galaxy Survey (SDSS-2dF-6dF Survey) and ULIRGs in the IRAS 1 Jy sample are compared. We find that the infrared properties are quite similar in both the far infrared and the near infrared for those two samples. By using the IRAS two-color diagram and the 2MASS two-color diagram we find that 24 sources in the SDSS-2dF-6dF Survey are candidate Seyfert 1-like sources indicative of strong AGN-dominant nature.

The gas fraction is important for understanding the formation and evolution of galaxies. It is found that there are linear correlations between the atomic-gas-to-stellar mass ratio (G/S) and stellar population properties (age, metallicity and stellar mass) of galaxies. However, only a nearby galaxy sample was used. This work investigates how the correlations change with the redshift limit of galaxies, using three volume limited galaxy samples selected from Sloan Digital Sky Survey (SDSS). It shows that there are linear correlations between the G/S and logarithmic values of stellar age, metallicity and mass, for all galaxy samples. It also shows that the linear correlation between G/S and stellar age is much better than others and possibly can be used in future studies. In addition, the scatters of the fitted correlations are found to increase with upper redshift limit of sample galaxies.

The submillimeter (submm) extragalactic background light (EBL) traces the integrated star formation history throughout the cosmic time. Deep blank-field 850 μm and 1.4 GHz surveys and optical follow-up have been only able to determine the redshift of ∼20% of the submm EBL. The majority (80%) of the submm EBL is still below the confusion and sensitivity limits of current submm and radio instruments. We break through these limits with stacking analyses on our deep 850 μm image in the GOODS-N and find that the submm EBL mostly comes from galaxies at redshifts around 1.0. This redshift is much lower than the redshift of z=2–3 previously implied from radio identified submm sources. This result significantly decreases the number of high redshift galaxies that may be seen by ALMA.

In this work we investigate the evolution of matter density perturbations for quintessence models with a self-interaction potential that is a combination of exponentials. One of the models is based on the Einstein theory of gravity, while the other is based on the Brans-Dicke scalar tensor theory. We constrain the parameter space of the models using the determinations for the growth rate of perturbations derived from data of the 2-degree Field Galaxy Redshift Survey., 5 pages, 3 eps figures

The Lehto-Tifft redshift quantization model is used to predict the redshift distribution for certain classes of quasars, and for galaxies in the neighborhood of z = 0.5. In the Lehto-Tifft model the redshift is presumed to arise from time dependent decay from an origin at the Planck scale; the decay process is a form of period doubling. Looking back in time reveals earlier stages of the process where redshifts should correspond to predictable fractions of the speed of light. Quasar redshift peaks are shown to correspond to the earliest simple fractions of c as predicted by the model. The sharp peaks present in deep field galaxy redshifts surveys are then shown to correspond to later stages in such a decay process. Highly discordant redshift associations are expected to occur and shown to be present in the deep field surveys. Peaks in redshift distributions appear to represent the spectrum of possible states at various stage of the decay process rather than physical structures.

The history of star formation in the Northern Hubble Deep Field is probed using a combination of optical and near infrared images taken with WFPC2 and NICMOS on the Hubble Space Telescope. These images cover more than a factor of five in wavelength. This broad wavelength coverage allows accurate photometric determinations of redshift, extinction and intrinsic spectral energy distribution for each galaxy. From these parameters the star formation rate for each galaxy is determined by relating the 1500 angstrom flux to the net star formation rate. We then correct the rates at high redshift for the effects of surface brightness dimming by using a standard form of the star formation intensity distribution. Our measurements show that the star formation rate in the Northern HDF is roughly constant from a redshift of 1 through 6.

Pure luminosity evolution models for galaxies provide an unacceptable fit to the redshifts and colors of faint galaxies. In this paper we demonstrate, using HST morphological number counts derived both from the $I_{814}$-band of WFPC2 in the Medium Deep Survey (MDS) and the Hubble Deep Field (HDF) and from the $H_{1.6}$-band of NICMOS, and ground-based spectroscopic data of the Hawaii Deep Field and the Canada-France Redshift Survey, that number evolution is necessary for galaxies, regardless of whether the cosmic geometry is flat, open, or $\Lambda$-dominated. Furthermore, we show that the number evolution is small at redshifts of z 1, and that this conclusion is valid for all the three cosmological models under consideration. If the universe is open or $\Lambda$-dominated, the models, which are subject to the constraint of the conservation of the comoving mass density of galaxies, naturally predict a population of star-forming galaxies with the redshift distribution peaking at $z=2\sim3$, which seems to be consistent with the recent findings from Lyman-break photometric selection techniques. If the cosmological model is flat, however, the conservation of the comoving mass density is invalid. Hence, in order to account for the steep slope of B-band number counts at faint magnitudes in the flat universe, such a star-forming galaxy population has to be introduced ad hoc into the modelling alongside the merger assumption.

We present deep galaxy number counts and colours of K—band selected galaxy surveys. We argue that primeval galaxies are present within the survey data, but have remained unidentified. There are few objects with the colours of an L* elliptical galaxy at a redshift of z ≈ 1, in contradiction to standard luminosity evolution models. We present K—band photometry of the objects in a spectroscopic redshift survey selected at 21 < B < 22.5. The absolute K magnitudes of the galaxies are consistent with the no-evolution or pure luminosity evolution models. The excess faint blue galaxies seen in the B—band number counts at intermediate magnitudes are a result of a low normalization, and do not dominate the population until B ≈ 25. Extreme merging or excess dwarf models are not needed at z < 1.

A class of extremely luminous high-redshift galaxies has recently been detected in unbiased submillimetre-wave surveys using the Submillimetre Common-User Bolometer Array (SCUBA) camera at the James Clerk Maxwell Telescope. Most of the luminosity of these galaxies is emitted from warm interstellar dust grains, and they could be the high-redshift counterparts of the low-redshift ultraluminous infrared galaxies (ULIRGs). Only one - SMM J02399-0136 - has yet been studied in detail. Three other very luminous high-redshift dusty galaxies with well determined spectral energy distributions in the mid-infrared waveband are known - IRAS F10214+4724, H1413+117 and APM 08279+5255. These were detected serendipitously rather than in unbiased surveys, and are all gravitationally lensed by a foreground galaxy. Two - H 1413+117 and APM 08279+5255 - appear to emit a significantly greater fraction of their luminosity in the mid-infrared waveband as compared with both low-redshift ULIRGs and high-redshift submillimetre-selected galaxies. This can be explained by a systematically greater lensing magnification of hotter regions of the source as compared with cooler regions: differential magnification. This effect can confuse the interpretation of the properties of distant ultraluminous galaxies that are lensed by intervening galaxies, but offers a possible way to investigate the temperature distribution of dust in their nuclei on scales of tens of parsecs.

The Sloan Digital Sky Survey (SDSS) is going to carry out a uniform survey of π steradians of the sky in the Northern Galactic cap and ∼ 225 deg2 in the Southern Hemisphere. The survey consists of a photometric and a spectroscopic survey. The SDSS will generate accurate photometry in five bands of approximately tens of millions of galaxies, tens of millions of stars and roughly a million quasars. It will also take spectra and measure redshifts of approximately a million galaxies and ten thousand quasars. The main characteristics and components of the survey are a dedicated 2.5m telescope, wide field correctors for photometry and spectroscopy that will provide a field of view of ∼ 3 degrees, a photometric camera with 30 photometric and 22 astrometric CCDs, and two fibre-fed spectrographs of 320 fibres each. The survey will produce a publicly available science database of Terabytes dimensions.

An appreciable number of galaxies have been discovered in recent years which are assigned high redshifts. High redshift galaxies (HRGs) are used as cosmological tools for probing early universe and knowledge of star formation. However, literature search revealed some inconsistencies in identification of emission lines used for redshift determination in some of the HRGs. We re-examined the spectra of 15 HRGs, as examples, that are available in the published literature and show that the high values of redshift may have been assigned to these objects due to the misidentification of the observed lines. We demonstrate that the observed emission lines can be identified with alternative search lines at higher wavelengths which are blueshifted instead of the lines used for redshift measurements. Observed blueshifts can be interpreted in a model of multiple expanding universes.

X-ray clusters are powerful tools for the determination of cosmological parameters. More specifically, the combined knowledge of the redshift distribution of X-ray clusters together with the luminosity-temperature correlation, $L_X-T_X$ provides us a new test for constraining the mean density of the universe ${\Omega_{0}}$. After a brief description of this test, I will present the result of our first attempt to apply this test to current X-ray data.

We reexamine the statistics of discordant redshift galaxies in compact groups. We find that 43 out of 100 groups in the Hickson catalog contain at least one discordant redshift galaxy. We show that, despite the prevailing impression, all previous attempts have failed to explain this large number of discordant redshift galaxies. The order of magnitude excess survives all of our attempts to refine the sample.

This article reviews work carried out in South Africa on large-scale structures. It describes the first redshift survey and contributions towards the Southern Sky Redshift Survey and its extension. Surveys of the Hydra-Centaurus region, and behind the adjacent Milky Way, are also discussed. The plots and analyses derived from the “Southern Redshift Catalogue”, as well as very recent work in “visualization”, are presented.

We analyse the history of modern cosmology based on the redshift phenomenon and on the cosmic background radiation (CBR). We show the models of different authors for the interpretation of the redshift and how the tired light models predicted the correct value of 2.7 K temperature previous to Gamow and collaborators.

The SCUBA local universe galaxy survey is the first systematic survey of the local universe at submillimetre wavelengths. We have observed ~200 galaxies from the IRAS bright galaxy catalogue and the CfA optical redshift survey. The IRAS sample showed that our estimate of the luminosity function was potentially biased if a cold population of galaxies existed which would not have appeared in the IRAS BGS but would have been detected in a SCUBA blind survey. Here we present preliminary results from the optically selected sample which suggest that this is indeed the case.

Clusters of galaxies acting as gravitational lenses allow us to study the stellar content and evolutionary state of galaxies at much fainter levels than the usual spectroscopic limit. By selecting background galaxies which are close to the critical lines at high-z and with a photometric redshift z ≥ 1, one maximizes the probability of discovering galaxies with z ≈ 1 − 5. The amplification close to the critical lines is typically Δm ~ 2 to 3 mag, but it is still ~ 1 mag at a distance of 1′ from the cluster center (Fort and Mellier, 1994). Only well studied cluster-lenses, with a mass distribution highly constrained by multiple images, are useful for this purpose, in order to keep the amplification uncertainties below Δm lensing ~ 0.3 mag.

A gap in a distribution is the interval between two consecutive values. Gaps in the emission line redshift distribution of QSOs are analysed using up-to-date data comprising 371 objects. It is found that the distribution of gaps is not random, but follows a definite trend, depending on the mean value of the redshift in the region.

This paper is the second one of a series of papers on the redshift distribution of QSOs. In this paper, we shall study the influence of the selection effect in the identification of emission lines on the redshift distribution of QSOs more thoroughly than the previous paper (Zhouet al., 1983). If we assume that the QSO's redshift is cosmological, adopt the standard model, and consider the selection effect due to the redshift identification, the limiting apparent magnitude in the observation and the evolutionary effect of QSOs, we can compute the emission line redshift distribution for the so-called optically selected QSOs discovered by objective prism, grating prism technique alone, the QSOs discovered by positional methods or by colour technique and for whole QSOs, respectively (see Figures 6, 11, 12). The results of computation agree with the observations very well, especially for optically selected QSOs; the computational distribution has almost the same shape with the observational one. For this kind of the QSOs the computational distribution may give the positions and heights of all these observed peaks. The correlation coefficient γ between the calculated and observed distributions is larger than 0.95. It shows that (a) the peaks and dips in the redshift distribution of QSOs are mainly caused by the selection effect in the redshift identification, and (b) the redshift of QSOs is cosmological.

We use the QSO's in the catalog compiled by Hewitt and Burbidge (1980) as the sample to analyse for the selection effects in the redshift identification. The results show that the redshift distribution caused mainly by the selection effects has almost same global feature as those given by the observations. The analysis leads us to conclude that the observational redshift distribution of QSO's should be heavily affected by these selection effects, and that attention should be paid to them in the investigations of the redshift distribution, the origion of redshift, and the evolutionary properties of QSO's.

82 compact galaxies with measured redshift present in systems containing partly normal galaxies have been found, using Zwicky's Catalogues and Morphological Catalogue. For them the mean residual redshift $$\overline {\Delta V} = + 163 \pm 76km s^{ - 1}$$ has been obtained. The chance probability for this result is 0.015. A high frequency of compact galaxies among those with large discrepant redshift is remarked. Relatively compact normal galaxies also reveal a positive mean value of $$\overline {\Delta V}$$ . Redshift is correlated with magnitude in groups and pairs of compact galaxies, this depending in pairs on the linear separation and colours of the components. If a colour difference is present, the bluer member has the larger redshift in general. In contrast with the large luminosity deduced from the redshift for many field compacts, compact galaxies in systems are faint. The majority of the proposed associations between quasars and systems of normal galaxies are shown to be probably physical.

Significant correlation has been obtained between redshift and radio magnitude of quasars at 3 GHz emitted frequency.

Two-color diagrams including magnitudes from several photometric systems are investigated with respect to the possibility of determining from the integrated photometry the galaxy type and its redshift. The color indices of galaxies are calculated using the energy distribution curves of Colemanet al. (1980). It is shown that redshift determination at low values ofz requires an ultraviolet magnitude with λ0 shorter than 300 nm. At redshiftsz>0.6, the infrared magnitude photometry becomes important. Different sources of errors and uncertainties are discussed.

A new identification for spectral lines of the N-galaxy 3 C 371 is proposed. The resulting redshift isz=0.40.