789 research outputs found
Periodicities of Quasar Redshifts in Large Area Surveys
We test the periodicity of quasar redshifts in the 2dF and SDSS surveys. In
the overall surveys redshift peaks are already apparent in the brighter
quasars. But by analyzing sample areas in detail it is shown that the redshifts
fit very closely the long standing Karlssson formula and strongly suggest the
existence of preferred values in the distribution of quasar redshifts.
We introduce a powerful new test for groups of quasars of differing redshifts
which not only demonstrates the periodicity of the redshifts, but also their
physical association with a parent galaxy. Further such analyses of the large
area surveys should produce more information on the properties of the
periodicity.Comment: 23 pages, 14 figure
A Cluster of High Redshift Quasars with Apparent Diameter 2.3 Degrees
During analysis of the relation of quasars to galaxies in the 2dF deep field
a concentration of quasars was noted. Most striking was the closeness in
redshift of 14 quasars about the mean redshift z = 2.149 with a range of . The cluster in spite of its high redshift subtends an area of diameter
more than 2.3 degrees on the sky. At conventional redshift distance its
diameter would be 181 mega parsecs and the back should be receding with about
with respect to the front.Comment: 7 pages, 3 Figure
Time dilation in the supernova light curve and the variable mass hypothesis
The recently reported time dilation effect in Type Ia supernova SN 1995K has been claimed to rule out the static universe model of Narlikar & Arp. It is shown here that the variable mass hypothesis which accounts for the redshift phenomenon in the above static universe model does indeed predict the observed effect and that there is no conflict between the data of Leibundgut et al. and the predictions of this model
The Wolf effect and the Redshift of Quasars
We consider a simple model, based on currently accepted models for active
galactic nuclei, for a quasi-stellar object (QSO or ``quasar'') and examine the
influence that correlation- induced spectral changes (``The Wolf Effect'') may
have upon the redshifts of the optical emission lines.Comment: 13 pages, 3 figures. To be published in J. European Optical Soc. A:
Pure and Applied Optic
The Distribution of Redshifts in New Samples of Quasi-stellar Objects
Two new samples of QSOs have been constructed from recent surveys to test the
hypothesis that the redshift distribution of bright QSOs is periodic in
. The first of these comprises 57 different redshifts among all
known close pairs or multiple QSOs, with image separations 10\arcsec,
and the second consists of 39 QSOs selected through their X-ray emission and
their proximity to bright comparatively nearby active galaxies. The redshift
distributions of the samples are found to exhibit distinct peaks with a
periodic separation of in identical to that claimed
in earlier samples but now extended out to higher redshift peaks and 4.47, predicted by the formula but never seen before. The periodicity
is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogues. It is
present in these three datasets at an overall significance level -
, and appears not to be explicable by spectroscopic or similar
selection effects. Possible interpretations are briefly discussed.Comment: submitted for publication in the Astronomical Journal, 15 figure
Lopsided Galaxies, Weak Interactions and Boosting the Star Formation Rate
To investigate the link between weak tidal interactions in disk galaxies and
the boosting of their recent star formation, we obtain images and spatially
integrated spectra (3615A < lambda < 5315A) for 40 late-type spiral galaxies
(Sab-Sbc) with varying degrees of lopsidedness (a dynamical indicator of weak
interactions). We quantify lopsidedness as the amplitude of the m=1
Fourier component of the azimuthal surface brightness distribution, averaged
over a range of radii. We compare the young stellar content, quantified by
EW(H\delta_abs) and the strength of the 4000 Angstrom break (D_4000), with
lopsidedness and find a 3-4 sigma correlation between the two. We also find a
3.2 sigma correlation between EW(H\beta_emission) and lopsidedness. Using the
evolutionary population synthesis code of Bruzual & Charlot we model the
spectra as an ``underlying population'' and a superimposed ``boost population''
with the aim of constraining the fractional boost in the SFR averaged over the
past 0.5 Gyr (the characteristic lifetime of lopsidedness). From the difference
in both EW(H\delta_abs) and D_4000 between the most and least symmetric thirds
of our sample, we infer that ~ 1x10^9 M_solar of stars are formed over the
duration of a lopsided event in addition to the ``underlying'' SFH (assuming a
final galactic stellar mass of 10^10 M_solar). This corresponds to a factor of
8 increase in the SFR over the past 5x10^8 years. For the nuclear spectra, all
of the above correlations except D_4000 vs. are weaker than for the disk,
indicating that in lopsided galaxies, the SF boost is not dominated by the
nucleus.Comment: 35 pages, including 10 figures, to appear in the Astrophysical
Journal, abridged abstrac
- âŠ