Quasars, Redshifts and the "accelerating-expansion" Universe.
Data, sky fields, & some thoughts on the right Cosmological model
This page provides links to the HMQ quasar catalog and the ARXA catalog of radio/X-ray associations, plus a few informal treatises on what we know, or can know, about our Universe.
"... the Universe is not only queerer than we suppose, but queerer than we can suppose.” -- J. B. S. Haldane
| The HALF MILLION QUASARS catalog
(HMQ: 2015, PASA 32, 10) is available here.
The count is 510,764 quasars, AGN and type 2 objects, including those of SDSS-DR12Q.
New: The MILLION OPTICAL RADIO/X-RAY ASSOCIATIONS catalog (MORX: 2016, PASA, accepted) is available here. It maps large-survey radio and X-ray sources onto 1,002,855 optical objects.
Milliquas is a "live" catalog of quasars and quasar candidates, totalling over 1.4M objects. Get it here.
A photo collection of QSOs/candidates positioned within galaxy disks (on the sky) is here, but nominal candidates within galaxy disks are usually due to bluish starburst zones and deblending artefacts. The fun is to find the true quasars amongst them.
Is redshift primarily cosmological? The bulk of the evidence says yes, but some published results show anomalies, even if sidestepped by the authors. A graphic example is from an Alan Stockton paper, with my commentary, here. And then there is NGC 7603. There appears to be more going on than is currently modelled. A standard interpretation of the physical redshift is that it shows time dilation of the photons. I think a viable alternative is that half comes from time dilation and the other half from spatial lengthening, both caused by the migration of a universal constant (or dimension) of "scale". The idea is that this universal constant is as yet unmodelled in our cosmology because it (the cosmology) hasn't been generalized enough.
What is dark matter? What is dark energy? You'll get as many different answers as the number of people that you ask, but one explanation is irrefutable: dark matter & dark energy are quantifications of how much we don't know. They are the gaps between the standard model and what is actually observed. That "dark matter" is so often elaborated as a form of matter, just shows the social power of a word. If the term instead was e.g., "gravitational scalar", then a more eclectic set of explanations would be presented. So the terms "dark matter" and "dark energy" are unfortunate.
Is today's cosmology run by a new generation of flat Earthers? People have grown so used to the Big Bang interpretation of the Universe, that they have grown inured to a sense of absurdity at the scenario of things flying apart at high speed. My view is that a more general theory will remove the need for physical expansion. The key point is the so-called "accelerating expansion" of the universe. This "acceleration" is entirely dependent on a flat-universe (Euclidean) model, and researchers are at pains to use the recent WMAP CMB data to claim a flat universe. But their claims may be wrong, as were the claims of the flat-Earthers, long ago. The key is to look at the recent paradigm, now expired, that the universe was at critical matter density (ΩM=1.00). Up until 1998 all studies, based on a variety of analyses, supported this paradigm. Then, in 1998, the distant supernova studies found that this could not be right, and that the matter density ΩM~0.3 and so must be (as required by a flat universe, where total Ω=1.0) balanced with a (dark) energy density ΩΛ~0.7. Since then all studies, based again on a variety of analyses, support the new paradigm. How can this be? It shows there is a powerful social component to today's astronomy which is overpowering true disinterested analysis. Similarly, the paradigm of a flat universe has endured since the advent of inflation theory as promulgated by Alan Guth in 1977.
Why is a flat universe such a key concept? Before 1998 when the universe was believed to be matter-dominated, it was thought that universal expansion was near enough to critical speed (where the universe neither expands forever nor collapses) that it was unlikely that this should be a coincidence, but was likely an initial condition. Guth's inflation theory provided a mechanism whereby critical density, and thus a flat universe, was attained as the result of a causal process. Balloon-borne measurements in the late 1990s (BOOMERanG) measured fluctuations in the CMB, and the angular extent of those fluctuations was considered to give a direct indication of the geometry of the universe, which was "found" to be flat. Before 1998 it was thought that a universe that expanded forever would have a hyperbolic ("open") manifold, and a universe which would eventually collapse would have a spherical ("closed") manifold. So the matter-dominated universe, at critical density, and with a flat geometry, was a consistent model with various confirmations.
Since 1998 the standard model has become that of an open forever-expanding universe, but the old idea that this would entail a hyperbolic manifold has not come with it. Instead, "dark energy" has been introduced to keep the universe's geometry flat. So, why keep the universe flat? Answer: because the Big Bang requires inflation (to accomodate the horizon problem, matter ratios, etc), and inflation is held to be a process which perforce yields a flat manifold. So the Big Bang and a flat universe are inseparable parts of the same theory.
Are the hyperbolic universe and the spherical universe viable alternatives to the flat universe? Not only are they viable, they are essentially mandatory. These "non-Euclidean" geometries are known to be mathematically complete and consistent, and the key point is that mathematically integral constructs generally have actual physical counterparts. We should expect to find non-Euclidean manifolds somewhere. Not either, but both hyperbolic and spherical spaces should exist.
How can hyperbolic and spherical spaces yield a viable alternative to the Big Bang? Let's combine them in the simplest way possible and see if they account for the universe as we observe it. We hypothesize that the universe is bounded at the largest scales by spherical space, and that the spherical space contains a hyperbolic space. Is this possible? It's not only possible, but mandatory that a hyperbolic space be enclosed by a spherical, as hyperbolic space carries with it an asymptote as a boundary point, i.e. the line in the cone X02-X12-X22 ... -Xn2 = 0. It follows that the boundary ∂Hn is a sphere. What would such a space look like to live in? It would look much like our universe; in fact it accounts nicely for the latest observations. The relevant observation is that "nearby" (z<0.5) objects are fainter than expected, therefore they are further away, thus "expansion" has "accelerated". But in a hyperbolic universe, the "shells of space" at distance R are larger than the standard 4πR², and so objects there look smaller and fainter than in a flat universe. The two tweakable parameters in this model are the degree of hyperbolicity and the radius of a spatial-5D spherical universe which contains the hyperbolic space; these can be combined to match the observations elegantly, without need of accelerated expansion. Thus two large extra dimensions are required, either spatial or a time-space composite. These extra dimensions can also yield cosmological redshift without the need for physical expansion at all, much less accelerated expansion, thus the model is a static anti-deSitter (AdS) model of the universe which I call the "Hypatia" model.
A brief presentation of the Hypatia model is here. In January 1998 I introduced it with this essay , which had enthusiasm but little math, and errors/speculations in the discussions on redshift. It was a humble beginning.
Index to my 1990s postings on sci.physics/sci.astro is here. Some good speculations, others not. In early days I was intrigued by the ideas of Halton Arp, and investigated them via my catalog processing. Dr. Arp was gracious throughout, and along the way we published a paper together. In the end I found that the bulk data did not support his notion of nearby quasars -- which however still leaves intriguing galaxy-quasar configurations such as with NGC 3628. Sometimes I feel like I am looking at ghosts or Christmas tree lights out there, but it's not enough to work with.
An interesting topic is the many faint galaxies found along the line of sight to quasars -- the "proximity effect". My idea is that these might be reflections of galaxies offset further away, and that some kind of quantum shear effect is responsible, i.e. a new kind of lensing. A topic worth watching.
Topics of note:
For a superior presentation of the history and outline of the standard model, refer paper by B. Leibundgut: http://www.eso.org/~bleibund/papers/EPN/epn.html
Last updated 20 September 2016.
© Eric Flesch 2016