Yale Astronomer Discovers Upper Mass Limit For Black Holes

There appears to be an upper limit to how big the universe's most massive black holes can get, according to new research led by a Yale University astrophysicist.
Once considered rare and exotic objects, black holes are now known to exist throughout the universe, with the largest and most massive found at the centers of the largest galaxies. These "ultra-massive" black holes have been shown to have masses upwards of one billion times that of our own Sun.
Now, Priyamvada Natarajan, an associate professor of astronomy and physics at Yale University and a fellow at the Radcliffe Institute for Advanced Study, and Ezequiel Treister, a postdoctoral fellow at the University of Hawaii, have shown that even the biggest of these gravitational monsters can't keep growing forever.
Instead, they appear to curb their own growth - once they accumulate about 10 billion times the mass of the Sun.
These ultra-massive black holes, found at the centers of giant elliptical galaxies in huge galaxy clusters, are the biggest in the known universe. Even the large black hole at the center of our own Milky Way galaxy is thousands of times less massive than these behemoths.
But these gigantic black holes, which accumulate mass by sucking in matter from neighboring gas, dust and stars, seem unable to grow beyond this limit regardless of where - and when - they appear in the universe. "It's not just happening today," said Natarajan. "They shut off at every epoch in the universe."
The study, to appear in the Monthly Notices of the Royal Astronomical Society (MNRAS), represents the first time an upper mass limit has been derived for black holes. Natarajan and Treister used existing optical and X-ray data of these ultra-massive black holes to show that, in order for those various observations to be consistent, the black holes must essentially shut off at some point in their evolution.
One possible explanation put forth by Natarajan is that the black holes eventually reach the point when they radiate so much energy as they consume their surroundings that they end up interfering with the very gas supply that feeds them, which may interrupt nearby star formation.
The new findings have implications for the future study of galaxy formation, since many of the largest galaxies in the universe appear to co-evolve along with the black holes at their centers.
"Evidence has been mounting for the key role that black holes play in the process of galaxy formation," said Natarajan. "But it now appears that they are likely the prima donnas of this space opera."
The authors of the paper are Priyamvada Natarajan (Yale University and the Radcliffe Institute for Advanced Study) and Ezequiel Treister (European Southern Observatory, Chile and University of Hawaii).

NOAA-N Prime Satellite Launch At Feb 4 ,2009

The latest polar-orbiting operational environmental weather satellite developed by NASA for the National Oceanic and Atmospheric Administration, or NOAA, called NOAA-N Prime, arrived Tuesday by C-5A military cargo aircraft at Vandenberg Air Force Base, Calif., in preparation for a February 4, 2009 launch. NOAA-N Prime, built by Lockheed Martin, is similar to NOAA-N launched on May 20, 2005.
The satellite will be launched from the Western Range at Vandenberg AFB by a United Launch Alliance two-stage Delta II rocket managed by NASA's Launch Service Program at the Kennedy Space Center, Fla.
NOAA-N Prime is the latest satellite in the Advanced Television Infrared Observational Satellites -N series built by Lockheed Martin Space Systems Company.
NOAA-N Prime will provide a polar-orbiting platform to support environmental monitoring instruments for imaging and measuring the Earth's atmosphere, its surface and cloud cover, including Earth radiation, atmospheric ozone, aerosol distribution, sea surface temperature, and vertical temperature and water profiles in the troposphere and stratosphere.
The satellite will assist in measuring proton and electron fluxes at orbit altitude, collecting data from remote platforms and will assist the Search and Rescue Satellite-Aided Tracking system.
NOAA-N Prime will be prepared for launch in a NASA payload processing facility located on north Vandenberg AFB. On Nov. 5, the satellite will be removed from its shipping container and rotated from the horizontal to vertical position. Spacecraft systems testing and launch preparations will then begin, which will take about a month.
Meanwhile, at the launch pad, the rocket that will launch NOAA-N Prime is a Delta II 7320 manufactured and prepared for launch by the United Launch Alliance. The first stage is scheduled to be erected on Space Launch Complex 2 on Dec. 2.
The three strap-on solid rocket boosters will be raised and attached to the booster the following day. The second stage which burns hypergolic propellants will be hoisted atop the first stage on Dec. 4. The fairing which will surround the spacecraft will then be hoisted into the clean room of the mobile service tower.
The following week, as a leak check, the first stage will be loaded with liquid oxygen during a simulated countdown. The following day, a simulated flight test will be performed simulating the vehicle's post-liftoff flight events without fuel aboard. The electrical and mechanical systems of the entire Delta II will be exercised during this test.
In mid-January, the NOAA-N Prime spacecraft will be hoisted atop the Delta II at the launch pad. The following week, a final major test is then ready to be conducted, which will involve the Delta II and NOAA-N Prime working together.
This will be a combined minus count and plus count, simulating all events as they will occur on launch day, but without propellants aboard the vehicle. Finally during the last week of January, the fairing will be installed around the spacecraft.
NOAA manages the polar-orbiting operational environmental weather satellite program and establishes requirements, provides all funding and distributes environmental satellite data for the United States. NASA's Goddard Space Flight Center in Greenbelt, Md., procures and manages the development and launch of the NOAA satellites for NOAA on a cost reimbursable basis.

NASA Selects Astronomy Student Ambassadors

Forty-six undergraduate and graduate students have been selected to represent NASA in their local communities as recipients of the agency's International Year of Astronomy, or IYA, Student Ambassadors Program.
Two of the students were chosen to attend the opening ceremonies of an IYA event in Paris in January 2009. The students representing NASA at the ceremonies are Rebecca Holmes, a sophomore at the University of North Carolina Chapel Hill who is majoring in physics and astronomy, and Norberto Gonzalez, a junior at the University of Puerto Rico at Arecibo with a biology concentration.
The IYA Student Ambassadors Program is designed to encourage undergraduate and graduate students to participate in IYA activities and generate excitement about NASA's discoveries in astrophysics, planetary science and solar physics within their local communities and beyond. These students will serve as role models to others.
"NASA is a major partner in the United States' celebration of IYA activities," said Hashima Hasan, NASA's Astrophysics education and public outreach lead in Washington. "The Student Ambassadors Program is just one of many activities the agency has planned throughout the coming year."
The ambassadors were selected from more than 150 online applications. Applicants must be U.S. citizens, full-time students and participate in activities that align with NASA's IYA goals.

Universal Declaration Of Human Rights Flies Into Space

Paris, France (ESA) Nov 07, 2008 - "All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a sprit of brotherhood", states Article 1 of the Universal Declaration of Human Rights (UDHR). 60 years after its adoption by the United Nations General Assembly at the Palais de Chaillot in Paris on 10 December 1948, the Declaration is ready to ... more

Paris, France (SPX) Nov 05, 2008 - A robot rover designed by a Bremen university team has won an ESA contest to retrieve soil samples from a lunar-style terrestrial crater. Eight student teams fielded rovers during the event, their progress monitored by an advanced 3-D viewer already flight-tested in space and planned for eventual deployment on the Moon. Craters surrounding the Moon's poles are a top 21st Century science ta ... more

Microspace Contracts Additional NSS-7 Satellite

SES NEW SKIES announces that Microspace has contracted an additional 5.5 Mbps of capacity on the NSS-7 satellite at the orbital location of 338 degrees East.
Microspace signed a five year agreement to provide uplink and bandwidth on NSS-7 from the Washington Mediaport to Europe for "Next Generation Retail Digital Signage Applications."
Digital signage is a 1billion USD industry that's growing at a breakneck pace. This growth is due in part to its ability to deliver interactive, timely and informational advertising and entertainment content at points of sale.
Microspace's technology powers a significant number of North American digital signage networks. Current deployments represent signage in nearly 10,000 locations.
Joseph L. Amor III, Vice President and General Manager of Microspace, states: "Microspace has had a very good business relationship with SES NEW SKIES throughout the decade. Their service levels and satellite performance encourage us to continue doing business with them."
Microspace is contracted on multiple full and partial transponders across five satellites with SES: AMC-1, AMC-3, AMC-8, NSS-7 and NSS-806.
Andrew Ruszkowski, Vice President North American Sales at SES NEW SKIES, said: "NSS-7 at 338 degrees East is the world's leading video contribution satellite. Its extensive coverage of the Atlantic Ocean region makes it an ideal satellite for bringing content from the East Coast of the U.S. to Europe. We look forward to providing Microspace with reliable and high-performance satellite transmission capacity to grow their digital signage business in Europe."
NSS-7NSS-7 is a state-of-the-art, hybrid Ku- and C-band satellite located at 338 degrees East over the Atlantic Ocean, providing coverage of Europe, Africa, the Middle East, and the Americas.
The satellite is located at one of the hottest orbital locations for trans-Atlantic connectivity as well as internet connectivity from North America into Europe, the Middle East and Africa. The powerful, state-of-the-art spacecraft features 49 C-band transponders and 48 Ku-band transponders.