Tag Archives: Supermassive Black Hole

A study (referenced below) led by a University of Utah astrophysicist found a new explanation for the growth of supermassive black holes in the center of most galaxies: they repeatedly capture and swallow single stars from pairs of stars that wander too close.

Using new calculations and previous observations of our own Milky Way and other galaxies, “we found black holes grow enormously as a result of sucking in captured binary star partners,” says physics and astronomy Professor Ben Bromley, lead author of the study, which is set for online publication April 2 in Astrophysical Journal Letters. Read More →

This image shows the bright emission from carbon and dust in the galaxy surrounding the most distant

Using the IRAM array of millimetre-wave telescopes in the French Alps, a team of European astronomers from Germany, the UK and France has discovered a large reservoir of gas and dust in a galaxy that surrounds the most distant supermassive black hole known. Light from the galaxy, called J1120+0641, has taken so long to reach us that the galaxy is seen as it was only 740 million years after the Big Bang, when the universe was only 1/18th of its current age.

Team leader Dr. Bram Venemans of the Max-Planck Institute for Astronomy in Heidelberg, Germany will present the new discovery on Wednesday 28th March at the RAS / AG National Astronomy Meeting in Manchester, United Kingdom. The Institut de Radioastronomie Millimetrique (IRAM) array is made up of six 15-m size telescopes that detect emission at millimeter wavelengths (about a thousand times as long as visible light) sited on the 2550-m high Plateau de Bure in the French Alps. The IRAM telescopes work together to simulate a single much larger telescope in a so-called interferometer that can study objects in fine detail.

A recent upgrade to IRAM allowed the scientists to detect the newly discovered gas and dust that includes significant quantities of carbon. This is quite unexpected, as the chemical element carbon is created via nuclear fusion of helium in the centres of massive stars and ejected into the galaxy when these stars end their lives in dramatic supernova explosions.

Dr Venemans comments: “It’s really puzzling that such an enormous amount of carbon-enriched gas could have formed at these early times in the universe. The presence of so much carbon confirms that massive star formation must have occurred in the short period between the Big Bang and the time we are now observing the galaxy.”

From the emission from the dust, Venemans and his team were able to show that the galaxy is still forming stars at a rate that is 100 time higher than in our Milky Way. The team give credit to the IRAM upgrade that made the new discovery possible.

 

“Indeed, we would not have been able to detect this emission only a couple of years ago.” says team member Dr Pierre Cox, director of IRAM.

The astronomers are excited about the fact that this source is also visible from the southern hemisphere where the Atacama Large Millimeter/submillimeter Array (ALMA), which will be the world’s most advanced sub/millimeter telescope array, is currently 2 under construction in Chile. Observations with ALMA will enable a detailed study of the structure of this galaxy, including the way the gas and dust moves within it.

Dr Richard McMahon, a member of the team from the University of Cambridge in the UK is looking forward to when ALMA is fully operational later this year. “The current observations only provide a glimpse of what ALMA will be capable of when we use it to study the formation of the first generation of galaxies.”

Source: Max-Planck Institute for Astronomy

Image Credits: ESO/UKIDSS/SDSS)

Reference:

B. P. Venemans, R. G. McMahon, F. Walter, R. Decarli, P. Cox, R. Neri, P. Hewett, D. J. Mortlock, C. Simpson, & S. J. Warren (2012). Detection of atomic carbon [CII] 158 micron and dust emission from a
z=7.1 quasar host galaxy APJ Letters arXiv: 1203.5844v1

ResearchBlogging.org

Image Credit: Artist concept credit: ESA/AOES Medialab)

The understanding of the way in which supermassive black holes shape galaxies is quickly changing, considering that new data is helping astrophysicists to grasp ultra-fast outflows. There is apparently a correlation between central black holes in galaxies and the velocity of stars in the system. An international team at the Goddard Space Flight Center believes that they have identified a particular outflow model that forges a link between black holes and these velocities.

The current understanding is that supermassive black holes make up the center of most decent sized galaxies. Galatic systems that have additional large black holes seem to have bulges where there are faster-moving stars. There seems to be some sort of a feedback loop between star formation and the black hole. However, as of yet, there is no real solid correlation for why this is.

Recent data that was collected by the project, though, explains that ultra-fast outflows might be speeding up these processes. While they’re not as fast as particle jets, ultra-fast outflows are probably making quicker star formation systems. One can hope that the Astro-H X-ray telescope project will help people better understand these concepts when it is presumably launched in 2014. Until that time, the Goddard Center will continue to look into the physical models behind the outflows.

Reference:
Tombesi, F., Cappi, M., Reeves, J., & Braito, V. (2012). Evidence for ultrafast outflows in radio-quiet AGNs – III. Location and energetics Monthly Notices of the Royal Astronomical Society: Letters DOI: 10.1111/j.1745-3933.2012.01221.x

Tombesi, F., Cappi, M., Reeves, J., Palumbo, G., Braito, V., & Dadina, M. (2011). EVIDENCE FOR ULTRA-FAST OUTFLOWS IN RADIO-QUIET ACTIVE GALACTIC NUCLEI. II. DETAILED PHOTOIONIZATION MODELING OF Fe K-SHELL ABSORPTION LINES The Astrophysical Journal, 742 (1) DOI: 10.1088/0004-637X/742/1/44

Tombesi, F., Cappi, M., Reeves, J., Palumbo, G., Yaqoob, T., Braito, V., & Dadina, M. (2010). Evidence for ultra-fast outflows in radio-quiet AGNs Astronomy and Astrophysics, 521 DOI: 10.1051/0004-6361/200913440

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At the center of the Milky Way galaxy (encompasses our solar system) there is a black hole that features a mass of more than three million times that of the sun at its center. This black hole, known as Sagittarius A (SGR A for short), has been detected through various sources of radiation that stem from the direction of the center of the galaxy. However, SGR A has now been found to be grazing and vaporizing asteroids that pass near it according to recent data released from NASA’s Chandra X-ray Observatory. This discovery comes with the finding that there is a cloud of trillions of asteroids and comets hovering around the black hole. Such a finding redefines the current environmental criteria for an asteroid or comet to form in space.

SGR A has likely been consuming tremendous numbers of asteroids as of late as the black hole has been emanating x-ray radiation in larger quantities than usual. Black holes hold true to the notion that ‘what goes in must come out,’ so they often spit out high amounts of radiation as they consume stellar objects. The asteroids and comets from the nearby cloud that pass within approximately 100 million miles of SGR A are likely hopelessly shredded. The space rocks are destroyed due to the high tidal forces associated with the black hole’s mass which creates enormous friction. The asteroids and comets are ripped apart in a similar fashion by which Saturn forms its rings with the exception that these rocks burn up like a meteor. This discovery is just one more clue to the overall mystery of the Milky Way galaxy.

Image credit: universetoday.com