Author: Vladimir Kladov, 2025.
Abstract. The source of the most part of the light radiated by the spiral galaxy arms are not stars located in those spiral arms, but an overheated plasma moving from the center of a galaxy to its bounds in two opposite directions with the speed kc where 0.001 < k < 0.3.
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All the variety of shapes of "spiral arms" can be explained the first by the angle on which the galaxy is observed, by the angle between rotating axis of the black hole and the axis of precession and also by amount of the matter in the galaxy which can make black holes active and to become lighten by the plasma emitted by them.
Keywords:
spiral, arms, galaxies, black, holes, precession, accretion, disks, morphology
Introduction
In the submitted article the model of forming the spiral arms of galaxies is suggested on base of a single physical process: jetting a stream of the matter from the kernel of a galaxy in two opposite directions, while the axis along which the matter is emitted is changing gradually.
A programming model of the physical process suggested that the results are matching very well to the images of galaxies obtained in different wave ranges (optical. infra-red, ultra-violet, X-ray etc.)
1. Generating of two opposite beams of plasma
At the center of a galaxy a black hole (B.H.) or or sometimes a system of black holes are located with a total mass of the same order as the total mass of all the stars, planets, dust and gas in the galaxy. In our Milky Way a super-massive black hole is located in the Sagittarius constellation and it is now under a close observation of out astronomers ([6]).
The modern astrophysics already suggested a probable physical phenomenon which leads to emission of two opposite streams of matter and energy from two poles of a black hole as a result of matter interaction in its accretion disk.
Figure 1: Black hole (a), its accretion disk (b) and emission of light in two opposite directions (c)
It is possible that another variants of the mechanism of creating plasma beams is working, e.g. a breakaway of a matter from an accretion disk in two opposite points of a black hole orbiting the SMBH in result of the a tide influenced by the gravity of the SMBH.
For us it is not important here which certain mechanism leads to ejecting two streams of luminous plasma in two opposite directions. It is just supposed that such streams exist.
2. Forming double spiral
In case of emitting of the matter from the poles of a black hole which rotating axis is tilted to some angle when a precession is applied for this axis which in result forms a cone in the space. If the precession speed is slow enough and entire circle is finished during hundreds of thousands or millions years then the matter ejected by the black hole for that time forms a spiral-like line in the space.
Then either the matter emitted is a super-heated plasma, and it emits a radiation in all ranges of waves lightening surrounding matter (gas, dust clouds) creating visually observing spiral-like line. Or it collides the gas and dust in the galaxy disk causing its glow and spreading in directions outward the spiral formed by the plasma. Or both effects take place.
Figure 2: Double spiral formed by plasma beams emitted from the galaxy center
Each point of this spiral is moving from the center of the galaxy to its bounds. The final spiral is not rotating, it is just expanding. But for us this occur very slow and for a hundred years of the observing astronomy we can not discover any sufficient changes.
Figure 2A: The animated model of forming double spiral arms
To form such spiral in a galaxy with the radius 100,000 light-years if the plasma speed v=0.1c then about 1 million years is enough to wait.
3. The main sentence (hypothesis)
The most part of the light radiated by the spiral arms of galaxies is formed not by stars locating in these arms but by the plasma ejected from the central black hole of a galaxy in two opposite directions.
These spiral arms are not rotating but instead are formed by the trace of light from the plasma moving from the center to the bounds of the galaxy. The spiral form of arms is a result of a slow rotation of the source of the plasma which is the black hole at the center of the galaxy.
The plasma which left the main galaxy "disk" later is moving in the deep vacuum dissipating in the halo surrounding the galaxy and then it becomes the part of it.
4 Modeling a spiral galaxy
Building a programmatic model of a spiral galaxy is not too hard. Following parameters are important:
- coefficient (0<k<1) which is multiplied to the light speed c to obtain a final plasma speed in the galaxy v = kc,
- the galaxy radius (R=1000..1,000,000) in light years,
- the tilt angle (0<tau<90) between the rotating axis of the black hole and the perpendicular to the falaxy plane,
- the precession period (T=1000..10,000,000) on which the rotating axis of the black hole is circumcircles a cone in the space,
- the inclination angle (alpha=-90..+90) between the galaxy plane and the picture plane,
- modeling mode (amount of black holes, precession),
and also some additional parameters affecting the exterior (colorization, sizes etc.) or performance of the model (frequency of generating "moving spots of plasma").
The first part of the model which works as interactive just shows positions of modeled spots of plasma in the view plane ignoring the time necessary for the light to achieve that plane. But the time necessary to become visible on one of defined view planes is calculated and coordinates of the spots visible simultaneously are saved together for further building the final image.
In the second part the final image is restored on base of data collected in the first (interactive) model.
For example for a galaxy with the inclination -45 degree (minus means that the upper part of the galaxy disk is located farther) to the picture plane depending on speed of plasma moving (kc) the restored picture of the galaxy is changing as shown on the follows image (for simplification the modeling was done for the case when the tilt between the axis of the black hole and the precession axis is exactly 90 degree).
Figure 3: The galaxy view depending on the plasma moving speed kc, for the galaxy with plain inclined on -45 degree.
From the image above (3) we can view that for k < 0.4 the resulting picture is looking very like to images of spiral galaxies we receive from real galaxies. Though for the case when k=1 (or near) the picture is too warped even for not too inclined galaxies.
The estimation k < 0.4 is just the upper restriction of the plasma speed. But the lower estimation can be done very roughly = on base of a fact that there were no changed found in the images of the ending parts or spiral arms of observed galaxies. And this mean that the velocity of plasma should be estimated in range k= 0.01 .. 0.03. [Or may be we just see not carefully enough?]
With the plasma which was broken to the velocity kc after emitting it from the black hole the black hole also emits a lot of electromagnetic waves in all the ranges focused in the same (two) directions (and these can not be broken). As a result the visual picture from the upper row (when k < 0.4) is composed to the image obtained for k=1 (but below picture is overlapped may be in some invisible ranges).
While moving spiral arms of radiation are expanding with the speed of the light (c) which is several times faster then the visible spirals of the plasma periodically overtaking it and intersecting with it may be additionally "heating" it (to compensate its constant cooling down for the power of the central super-massive black hole).
7 Allocating spiral arms in space
In many cases the angle between the rotating axis of the super-massive black hole is not equal to 90 degree and in such cases spiral arms are located not in the same plane but instead formed along two imaginary double cones formed by sliding the rotation axis of the black hole around the precession axis. For small such tilt angles the model shows sometimes complex enough trajectories not observable in reality.
Figure 5: Galactic model with the inclination to the view plane -45 degree and a tilt between black hole rotation axis and the precession axis (a value)
Actually as it was said above the plasma is decelerating for some time after emitting and in all the cases the central area will be either overlapped by the luminous ellipse or transformed to a long straight line ("bridge").
In case when the source of the plasma streams is the interaction of two accretion disks the spiral arms forming along two cones can be explained by some angle between planes of those accretion disks.
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