|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
New technique for measuring black hole mass, yields universe's smallestblack hole ever
Smallest Black Hole Ever Discovered Has Amazing Tidal Force
"The method used by Shaposhnikov and Titarchuk has been described in several papers in the Astrophysical Journal. It uses a relationship between black holes and the inner part of their surrounding disks, where gas spirals inward before making the fatal plunge. When the feeding frenzy reaches a moderate rate, hot gas piles up near the black hole and radiates a torrent of X-rays. The X-ray intensity varies in a pattern that repeats itself over a nearly regular interval. This signal is called a quasi-periodic oscillation, or QPO. Astronomers have long suspected that a QPO's frequency depends on the black hole's mass. In 1998, Titarchuk realized that the congestion zone lies close in for small black holes, so the QPO clock ticks quickly. As black holes increase in mass, the congestion zone is pushed farther out, so the QPO clock ticks slower and slower. To measure the black hole masses, Shaposhnikov and Titarchuk use archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes." http://www.sciencedaily.com/releases...0401141549.htm |
#2
|
|||
|
|||
New technique for measuring black hole mass, yields universe'ssmallestblack hole ever
Yousuf Khan wrote:
Smallest Black Hole Ever Discovered Has Amazing Tidal Force "The method used by Shaposhnikov and Titarchuk has been described in several papers in the Astrophysical Journal. It uses a relationship between black holes and the inner part of their surrounding disks, where gas spirals inward before making the fatal plunge. When the feeding frenzy reaches a moderate rate, hot gas piles up near the black hole and radiates a torrent of X-rays. The X-ray intensity varies in a pattern that repeats itself over a nearly regular interval. This signal is called a quasi-periodic oscillation, or QPO. Astronomers have long suspected that a QPO's frequency depends on the black hole's mass. In 1998, Titarchuk realized that the congestion zone lies close in for small black holes, so the QPO clock ticks quickly. As black holes increase in mass, the congestion zone is pushed farther out, so the QPO clock ticks slower and slower. To measure the black hole masses, Shaposhnikov and Titarchuk use archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes." http://www.sciencedaily.com/releases...0401141549.htm Two fun parts: First, if the binary system's orbit is accurately described by General Relativity, black holes obey the Equivalence Principle. Second, the mass of the black hole is vastly smaller than the summed masses of separated baryons that condensed to form it - gravitational binding energy. 1.74 solar-mass pulsar PSR J1903+0327 is in a 95.17-day 0.437-eccentricity orbit with its 1.05 solar-mass star companion. Respective gravitational binding energies are 27% vs. 1.4x10^(-4)%. Thus the neutron star assembled from 2.38 solar masses. What is the gravitational binding energy of the black hole? -- Uncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz4.htm |
#3
|
|||
|
|||
New technique for measuring black hole mass, yields universe's smallest black hole ever
Yousuf Khan wrote:
Smallest Black Hole Ever Discovered Has Amazing Tidal Force "The method used by Shaposhnikov and Titarchuk has been described in several papers in the Astrophysical Journal. It uses a relationship between black holes and the inner part of their surrounding disks, where gas spirals inward before making the fatal plunge. When the feeding frenzy reaches a moderate rate, hot gas piles up near the black hole and radiates a torrent of X-rays. The X-ray intensity varies in a pattern that repeats itself over a nearly regular interval. This signal is called a quasi-periodic oscillation, or QPO. This is not new. We have been measuring black hole mass and spin via this method for probably close to a decade now. This has the irritating feature of being a model dependent prediction as the nature of the oscillations depend on what's being assumed. The current working theory for accretion dynamics is the radiatively inefficient accretion flow [RIAF] model. Astronomers have long suspected that a QPO's frequency depends on the black hole's mass. In 1998, Titarchuk realized that the congestion zone lies close in for small black holes, so the QPO clock ticks quickly. As black holes increase in mass, the congestion zone is pushed farther out, so the QPO clock ticks slower and slower. To measure the black hole masses, Shaposhnikov and Titarchuk use archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes." http://www.sciencedaily.com/releases...0401141549.htm The only new thing about this is that it is confirmed over a wider scale of black hole masses. Still interesting, which is why I'm ****ed off I couldn't find it at the UW library. Then again, I was looking at the wrong year since it was published in TWO THOUSAND ****ING EIGHT. Thanks for the current event. |
#4
|
|||
|
|||
New technique for measuring black hole mass, yields universe's smallestblack hole ever
Uncle Al wrote:
Yousuf Khan wrote: Smallest Black Hole Ever Discovered Has Amazing Tidal Force "The method used by Shaposhnikov and Titarchuk has been described in several papers in the Astrophysical Journal. It uses a relationship between black holes and the inner part of their surrounding disks, where gas spirals inward before making the fatal plunge. When the feeding frenzy reaches a moderate rate, hot gas piles up near the black hole and radiates a torrent of X-rays. The X-ray intensity varies in a pattern that repeats itself over a nearly regular interval. This signal is called a quasi-periodic oscillation, or QPO. Astronomers have long suspected that a QPO's frequency depends on the black hole's mass. In 1998, Titarchuk realized that the congestion zone lies close in for small black holes, so the QPO clock ticks quickly. As black holes increase in mass, the congestion zone is pushed farther out, so the QPO clock ticks slower and slower. To measure the black hole masses, Shaposhnikov and Titarchuk use archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes." http://www.sciencedaily.com/releases...0401141549.htm Two fun parts: First, if the binary system's orbit is accurately described by General Relativity, black holes obey the Equivalence Principle. Second, the mass of the black hole is vastly smaller than the summed masses of separated baryons that condensed to form it - gravitational binding energy. 1.74 solar-mass pulsar PSR J1903+0327 is in a 95.17-day 0.437-eccentricity orbit with its 1.05 solar-mass star companion. Respective gravitational binding energies are 27% vs. 1.4x10^(-4)%. Thus the neutron star assembled from 2.38 solar masses. What is the gravitational binding energy of the black hole? What's the meaning of the term for a black hole? You can't disassemble the construct to provide a valid comparison. The only mass for a black hole that matters is its' gravitational mass. |
#5
|
|||
|
|||
New technique for measuring black hole mass, yields universe'ssmallest black hole ever
eric gisse wrote:
Yousuf Khan wrote: Smallest Black Hole Ever Discovered Has Amazing Tidal Force "The method used by Shaposhnikov and Titarchuk has been described in several papers in the Astrophysical Journal. It uses a relationship between black holes and the inner part of their surrounding disks, where gas spirals inward before making the fatal plunge. When the feeding frenzy reaches a moderate rate, hot gas piles up near the black hole and radiates a torrent of X-rays. The X-ray intensity varies in a pattern that repeats itself over a nearly regular interval. This signal is called a quasi-periodic oscillation, or QPO. This is not new. We have been measuring black hole mass and spin via this method for probably close to a decade now. This has the irritating feature of being a model dependent prediction as the nature of the oscillations depend on what's being assumed. Which seems to be close to what was stated in the article. Astronomers have long suspected that a QPO's frequency depends on the black hole's mass. In 1998, Titarchuk realized that the congestion zone lies close in for small black holes, so the QPO clock ticks quickly. As black holes increase in mass, the congestion zone is pushed farther out, so the QPO clock ticks slower and slower. To measure the black hole masses, Shaposhnikov and Titarchuk use archival data from RXTE, which has made exquisitely precise measurements of QPO frequencies in at least 15 black holes." http://www.sciencedaily.com/releases...0401141549.htm The only new thing about this is that it is confirmed over a wider scale of black hole masses. Still interesting, which is why I'm ****ed off I couldn't find it at the UW library. Then again, I was looking at the wrong year since it was published in TWO THOUSAND ****ING EIGHT. Thanks for the current event. It's a year old, but still current, since I haven't seen anything newer about it. Yousuf Khan |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
observed black hole mass | RichD | Astronomy Misc | 8 | March 24th 09 06:16 AM |
Black Hole with a mass of 300 Billion Suns | G=EMC^2 Glazier[_1_] | Misc | 5 | July 31st 07 01:33 AM |
Black Hole Critical Mass Is ??? | G=EMC^2 Glazier | Misc | 58 | December 17th 06 06:56 PM |
Mass + acceleration = Black Hole | G=EMC^2 Glazier | Misc | 2 | November 24th 06 05:31 PM |
Possible intermediate-mass black hole | Ray Vingnutte | Misc | 0 | March 26th 05 01:46 AM |