Mass of a Black Hole

[blike]

Astronomers from Canada and the United Kingdom have measured the mass of a black hole swallowing a quasar 13 billion light years away. They used the UKIRT Imager Spectrometer to measure the infared spectrum emitted from the quasar. Dr. Chris Willott explained "We can determine the mass of the black holes in these distant quasars by looking at the MgII emission line and comparing it with the same emission line in closer quasars. The basic idea here is that the width of the line gives an indication of the speed of the gas close to the quasar. More massive black holes will have faster moving material." The team of researchers determined the black hole is one quadrillion times as massive as the earth. Thats 1,000,000,000,000,000 for the mathmatically imparied.

 

The team also noted that the black hole is swallowing the quasar at the maximum rate possible, called the "Eddington Limit". If the black whole was sucking matter in any faster, its luminosity would exert enough pressure to keep matter from falling in.

 

Source: spaceflightnow

[fafalone]

The size of a black hole is not fixed, it can consume more matter and dry up over time.

[blike]

Nor is the earth's mass, or sun's mass...but its still quite interesting to take measurements.

[fafalone]

The Earths mass remains essentially constant. When talking about a black hole, its mass changes by the addition of entire planets and stars... a significant change. Earths mass varies only by infinitesimal percentages. Same for the sun.

[DocBill]

Originally posted by fafalone

The Earths mass remains essentially constant. When talking about a black hole, its mass changes by the addition of entire planets and stars... a significant change. Earths mass varies only by infinitesimal percentages. Same for the sun.

 

Actually, a balck holes "Mass" is only meassured by what it "eats" as it is impossible to meassure something that isn't. A black hole's size can enlage, if two BH colide, or if it is "spun up" via a MS star. According to Stephen and others, in 100^40 years, all BH would have evaporated.

 

On a similar note, and all matter suffered from proton decay, and the cosmos will have returned to a cold, thin nothing.

 

so I will buy an suv if I want to..so there.

 

Bill

(The member who teaches astronomy)

[blike]

When we're dealing with numbers on the order of 1,000,000,000,000,000, the addition of a new planet even 1 billion times the size of earh is NOTHING.

[Physics5000]

At the American Physical Society Spring Meeting in Washington, D.C. on Monday, Tod Strohmayer of NASA's Goddard Space Flight Center presented concrete evidence that some black holes actually spin as they suck in their surroundings. "Almost every kind of object in space spins, such as planets, stars and galaxies," he says. "With black holes, it's much harder to directly see that they are spinning, because they don't have a solid surface that you can watch spin around." But he proved his case nevertheless using data from NASA's Rossi X-ray Timing Explorer Satellite. Strohmayer looked at GRO J1655-40, a microquasar black hole about 10,000 light years from earth. Jets of high-speed particles shoot straight up and down from this type of black hole (see image). And among the emanations, Strohmayer noticed two distinct patterns of flickering x-rays known as quasiperiodic oscillations, or QPOs—one previously detected QPO at 300 Hertz (Hz) and a new one at 450 Hz. Scientists had only ever detected this sort of radiation around spinning neutron stars.

The QPO at 450 Hz presented a puzzle. From it, Strohmayer calculated that GRO J1655-40's innermost stable orbit—the closest anything can circle the black hole without falling in-should be 49 kilometers or less. And yet based on the black hole's mass, estimated to be seven times greater than that of the sun, the innermost stable orbit should be 64 kilometers. The only way to resolve the contradiction, Strohmayer says, is if GRO J1655-40 spins: "A spinning black hole modifies the fabric of spacetime near it. The spinning allows matter to orbit at a closer distance than if it were not spinning, and the closer matter can get the faster it can orbit. For GRO J1655-40 we can now say that the only way for it to produce the 450 Hz QPO is if it is spinning." --Harald Franzen