Back hole in Cygnus X-I

[babaonet]

What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?

[bystander]

http://asterisk.apod.com/viewtopic.php?f=31&t=25067

[Chris Peterson]

What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?

There is no such thing as an unstable black hole (except possibly for the hypothetical class of microscopic black holes). When a black hole absorbs anything- be it dust or be it a star- it increases in mass by that amount. The other conserved properties are angular momentum and electric charge. That's it.

[babaonet]

Thank you Peterson, but what you think about the powerful gamma jet radiation during feeding, Such as in SW 1644+57?

[Chris Peterson]

Thank you Peterson, but what you think about the powerful gamma jet radiation during feeding, Such as in SW 1644+57?

Jets, accretion discs, and all the other active phenomena we see around black holes have nothing at all to do with black hole physics as such. They are all the indirect result of the mass, charge, and rotation of the black hole. This is why we see similar phenomena around other objects with those properties, like protostars and neutron stars.

[babaonet]

One more question please, as we know nothing can escape from black hole, even light too. But how those gamma ray jets manage to escape from black hole?

[Chris Peterson]

One more question please, as we know nothing can escape from black hole, even light too. But how those gamma ray jets manage to escape from black hole?

They don't, because the jets were never inside the black hole. As I said before, everything we see around black holes is caused by their influence on the environment around them. Jets are produced outside the black hole, so there is nothing preventing their radiation and material from escaping the region.

[babaonet]

Now i understand, thanks a lot.

[ErnieM]

What happens when a black hole gets close to another black hole? Is there such a phenomena as multiple black holes system? If black holes eventually eat each other, then one can imagine a single super massive black hole with two opposite super long and expansive jet streams. Is it inconceivable to imagine that this is the shape and geometry of our expanding "universe" (and others as there could be than one) and we presumably "live" in one of the Picard horn shaped jet stream?

[Chris Peterson]

What happens when a black hole gets close to another black hole? Is there such a phenomena as multiple black holes system?

They do exactly what any two objects do: depending on their initial velocities, they either end up in a closed orbit or they swing past each other and never come back together. There are many multiple (two) black hole systems, which commonly occur when galaxies collide.

If black holes eventually eat each other, then one can imagine a single super massive black hole with two opposite super long and expansive jet streams.

Black holes in orbit about each other eventually collide because they lose energy to the surrounding medium, and their orbits decay. When they collide they merge into a single, more massive black hole. It is hypothesized that many (or all) supermassive black holes formed from a string of black hole mergers. Whether a merged black hole will have jets, however, depends on the medium around it. If there isn't enough material to support an accretion disc, there won't be any jets. Even if one or both had accretion discs before the merger, the collision itself could disrupt or even absorb that material, which would actually shut off any jets that were present.

Is it inconceivable to imagine that this is the shape and geometry of our expanding "universe" (and others as there could be than one) and we presumably "live" in one of the Picard horn shaped jet stream?

Anything is conceivable. I don't think there is anything to support this idea, however. At the least, you'd need to allow for the fact that the number of dimensions that define the Universe is at least one greater than the number that define a jet.

[ErnieM]

Whether a merged black hole will have jets, however, depends on the medium around it. If there isn't enough material to support an accretion disc, there won't be any jets. Even if one or both had accretion discs before the merger, the collision itself could disrupt or even absorb that material, which would actually shut off any jets that were present.

The universe is mostly dark matter and dark energy in comparison to visible matter and visible energy. Then it is only logical to assume that most of the medium around a black hole are dark matter. Would this not result in a "dark jet stream" being present but not yet detectable by our instruments?

[Chris Peterson]

The universe is mostly dark matter and dark energy in comparison to visible matter and visible energy. Then it is only logical to assume that most of the medium around a black hole are dark matter. Would this not result in a "dark jet stream" being present but not yet detectable by our instruments?

No, for two reasons. Jets require an influx of material from a disc structure, that is then caught up in strong magnetic fields and ejected along the rotation axis. Dark matter doesn't form discs, but rather it forms halos (you need fluid dynamic processes to form a disc, and that isn't possible if the material doesn't interact with itself or other matter), and dark matter isn't influenced by magnetic fields. Dark matter may fall into a black hole, or orbit a black hole, both of which are purely gravitational effects. But there is no mechanism for dark matter to be ejected from the region around a black hole, other than the trivial (and non-relativistic) ejection of material via injection into hyperbolic orbits by angular momentum transfer processes.

[babaonet]

Is there a black hole in Cygnus X-I?

[ErnieM]

WMAP Measurements
The Wilkinson Microwave Anisotropy Probe (WMAP) was designed to achieve more precise measurements of the anisotropy in CMB. Within the framework of the "Lambda-CDM Model" of the universe, the WMAP data indicate that the age of the universe is 12.73 ± 0.12 billion years old.

WMAP data also indicate that the current universe consists of 4.6% ordinary baryonic matter; 23% unknown dark matter; 72% dark energy; and less than 1% neutrinos. The ratio of the energy density to to the critical density was determined to be 1.0052 ± 0.0064 . These findings created big excitement in the scientific community. The academic papers [1][2] of the WMAP collaboration were among the most cited papers in history.

Full article: http://knol.google.com/k/shape-of-the-universe#

In the same article, it was estimated that the 380,000 year old universe consisted of 12% atoms, 63% dark matter, 15% photons and 10% neutrinos.

The estimated changes in the make up of the universe, specifically the reduction of dark matter and the increase of dark energy, implies that dark matter is influenced by itself (internally) or by other "matters" (externally) through gravity and other phenomena.
How is dark matter converted into dark energy? Does dark matter follows Einstein's E = mc²?

[Chris Peterson]

Is there a black hole in Cygnus X-I?

Probably. That scenario provides the best fit to observational data.

[Chris Peterson]

Full article: http://knol.google.com/k/shape-of-the-universe#

There are elements in that article that make me skeptical, particularly the rather bizarre mix of Eastern philosophy with science. There are also factual errors, such as the suggestion that WMAP data leads to the conclusion that the Universe is 12.73 billion years old (the actual WMAP value is 13.69±0.13 billion years).

The estimated changes in the make up of the universe, specifically the reduction of dark matter and the increase of dark energy, implies that dark matter is influenced by itself (internally) or by other "matters" (externally) through gravity and other phenomena.
How is dark matter converted into dark energy? Does dark matter follows Einstein's E = mc²?

I don't follow your suggestion that the change in ratios of the components of the total energy budget carries an implication that dark matter influences itself. By direct observation we know that dark matter gravitationally influences itself; other mechanisms are currently unknown, and largely speculative. Any mechanisms behind the conversions are also largely speculative. Dark matter is simply another form of energy, so the mass-energy equivalence is present- an assumption that is fundamental to cosmological theory.

[ErnieM]

Code: Select all

I don't follow your suggestion that the change in ratios of the components of the total energy budget carries an implication that dark matter influences itself. 

It has been suggested that all organic matter decays and have a half-life. http://www.nature.com/nature/journal/v1 ... 464a0.html

Does this decay process(es) apply to dark matter?

[Chris Peterson]

It has been suggested that all organic matter decays and have a half-life. Does this decay process(es) apply to dark matter?

Nobody knows if all matter decays (not sure why you qualify this with "organic"). The paper you reference isn't useful, and much of Kapp's science-philosophy is demonstrably false. It is certainly possible that the proton decays, which is pretty much the same thing as saying matter has a half-life, although with a much larger value than Kapp proposed. But the question remains unsettled. And nobody knows much about dark matter, other than the broad suggestion that it is probably non-baryonic.

So anybody who actually claims a definitive answer to your question is probably somebody whose opinion you shouldn't put much faith in. There are still many questions best answered with "we simply don't yet know".

[alter-ego]

How is dark matter converted into dark energy?

DM and DE are not necessarily correlated, at least in the sense the one is, or can be, converted to another. Keep in mind that DM and DE are apparent entities that are not understood, but manifest themselves in comological observations and supported by GR (Lambda-CDM) model. Also, the concept of an expanding Universe was a direct consequence of GR, whence the origin of Lambda (Λ) the cosmological constant. It is interesting that DE and GR have an apparently intrinsic connection, but DM is not born from GR. Thus it seems reasonable, today, that DM and DE are viewed as distinct, uncorrelated, entities despite not knowing what they really are.

Does dark matter follows Einstein's E = mc²?

I think it's fair to say that since DM can be effectively mapped / modeled by gravitational lensing and stellar velocity distributions (e.g. within a galaxy), and the observed gravitational effects on its surroundings are not distinguishable from that due to baryonic (normal) matter, the idea of DM and energy equivalence is valid. However, applying Einstein's energy equivalence to DE does not make sense. DE / Vacuum Energy imply a repulsuve gravitational field.
[quote="Wiki"]The vacuum energy also has important consequences for physical cosmology. Special relativity predicts that energy is equivalent to mass, and therefore, if the vacuum energy is "really there", it should exert a gravitational force. Essentially, a non-zero vacuum energy is expected to contribute to the cosmological constant, which affects the expansion of the universe. In the special case of vacuum energy, general relativity stipulates that the gravitational field is proportional to ρ-3p (where ρ is the mass-energy density, and p is the pressure). Quantum theory of the vacuum further stipulates that the pressure of the zero-state vacuum energy is always negative and equal to ρ. Thus, the total of ρ-3p becomes -2ρ: A negative value. This calculation implies a repulsive gravitational field, giving rise to expansion, if indeed the vacuum ground state has non-zero energy. However, the vacuum energy is mathematically infinite without renormalization, which is based on the assumption that we can only measure energy in a relative sense, which is not true if we can observe it indirectly via the cosmological constant.[/quote]
All this does not preclude exotic theories that may propose a different interpretation of DE and DM. Whose to say that someday the essence of these things might understood, but much work is needed to bring those theories to be accepted and successful as GR is now.

[babaonet]

What is Cygnus X-I? Is there a black hole in Cygnus X-I?

[neufer]

http://asterisk.apod.com/viewtopic.php?t=25143#p157248

http://apod.nasa.gov/apod/ap080811.html
http://apod.nasa.gov/apod/ap090608.html
http://apod.nasa.gov/apod/ap960529.html
http://apod.nasa.gov/apod/ap090321.html
http://apod.nasa.gov/apod/ap070524.html
http://apod.nasa.gov/apod/ap050402.html

http://asterisk.apod.com/viewtopic.php?t=23221#p145584
http://asterisk.apod.com/viewtopic.php?t=24885#p155241
http://asterisk.apod.com/viewtopic.php?t=16950#p107113

[SpaceTas]

Cygnus X-1 is a double star system consisting of a normal hot blue super-giant star (20 - 40 times mass of Sun) star and a black hole of about 9 solar masses.
The mass of the compact object is estimated using the Doppler effect. Here the spectral lines in the light from the visible stars change wavelength as the star is dragged round in an orbit by the unseen companion. It is also a very bright X-ray source (the first discovered in the constellation of Cygnus). The x-ray variations show all the changes seen in other binary systems with black holes in them. The x-rays come from material pulled from the visible super-giant star into a disk about the black hole as material spirals inward it heats up to temperatures hot enough so that it emits x-rays. The x-rays come from the inner edge of the disk, and so variations on time-scales from microseconds to years.

[ErnieM]

What if a massive star falls into a black hole? Will the black hole remain stable? What change will be seen in the black hole? Who the black will tackle the additional mass?

Click to play embedded YouTube video.

Watch to learn more about black holes. From Space Rip - Published on Sep 26, 2012.