Mystery of Missing Galaxies

Small fluctuations in gravity measurements of gas at the edge of our own galaxy, lead scientists to suspect the existence of a previously unnoticed satellite galaxy near the Milky Way. This is written up in National Geeographic News and an official publication of the research is scheduled for the Astrophysical Journal.

This much smaller galaxy, may be invisible because of dark matter, and because it's non dark matter stars are quite dim, and it exists in a galactic plane hard for us to see, and because of clouds, gases, etc obscuring the penetration of telescopes: all reasons our close neighbor has not yet been noticed.  

The confirmation of this galaxy would be exciting since models of galactic formation in the aftermath of the big bang  predict a galaxy like ours should have many of these satellites, and yet, no one has found nearly enough to satisfy the mathematical calculations scientists are relying on. 

If the dwarf galaxy Dr. Chakrabarti is predicting is found:it will provide verification of scientists' predictions on the distribution of matter in the universe. This "missing satellite problem" she said, "is a fundamental problem in cosmology."  Should the galaxy NOT be found,  one alternative suggests  " there's some other oddity out there throwing off the calculations—perhaps an unexpected distribution pattern of the halo of dark matter thought to surround the Milky Way."

Culture at the Wall Street Journal

The Wall Street Journal, of December 29, 2010, has a book review on their opinion page. The review by Sam Sacks, discusses Heinrich Boll (1917-1985) and the reissue of some of Boll's novels: The Clown, 1963 and The Safety Net (1979).  Boll's theme according to Sacks, is that "German national pride is tainted by association with Nazism." This fact, that notice is taken of German citizens and their relation to nazism, 65 years after the war ended, and now noticed in the pages of the Wall Street Journal, noticed very mildly and with little inspiration or analysis, this fact, makes me wonder what kind of coverage this periodical gave to stories about the participation by industrialists during the last war. This fact, I assure you, belongs in a blog about weird news.

Why are poor people trying to help bankers avoid governmental restraint

Francis Fukuyama, a noted historian, raises the question of how accurate it is to consider America a plutocracy (rule of the wealthy) and whether the undeniable greater access to governmental power the wealthy have, is sufficient to explain the situation wherein many of the people hurt by the banking collapse in 2008, in fact seem to be supporting programs and policies that now benefit the banks and hurt themselves. That is his topic in an article in the American Interest, a resource I only just became familiar with, and which now I highly recommend. The ending is a bit disappointing in that he is forced to assess the situation as puzzling. It is still an enormous help to have someone outline the problems so nicely AND, his assessment of the role of economists themselves in these events is something I had not thought of at all. Fukuyama's article is entitle"Left Out," a multiple layered pun.

Mysterious source of some meteorites

Following are excerpts from a spaceref.com notice about an upcoming issue of  Meteoritics and Planetary Science. A car sized asteroid exploded over the Nubian desert in 2008. Now the evidence for the origin of this event in a celestial body which remains mysterious, is confirmed. What I don't understand though, in the article, is their putting all the fragments in one chamber to be analyzed. Wouldn't that mess up the signs they were analyzing? Anyway, fascinating look at what might be evidence of a proto-planet. (http://www.spaceref.com/news/viewpr.html?pid=32296)

Meteorite just one piece of an unknown celestial body
Source: Carnegie Institution
Posted Wednesday, December 15, 2010

...Now in a series of 20 papers for a special double issue of the journal Meteoritics and Planetary Science, published on December 15, researchers ...demonstrate the diversity of these [meteorite] fragments, with major implications for the meteorite's origin.

In the first round of research, Carnegie Geophysical scientist Doug Rumble, in collaboration with Muawia Shaddad of the University of Khartoum, examined one fragment of the asteroid, ... and determined that it fell into a very rare category of meteorite called ureilites. Ureilites have a very different composition from most other meteorites. It has been suggested that all members of this meteoric family might have originated from the same source, called the ureilite parent body, which could have been a proto-planet.

Now Rumble has expanded his work to examine 11 meteorite fragments, [from the same asteroid] focusing on the presence of oxygen isotopes. Isotopes are atoms of the same element that have extra neutrons in their nuclei.

Rumble explains: "Oxygen isotopes can be used to identify the meteorite's parent body and determine whether all the fragments indeed came from the same source. Each parent body of meteorites in the Solar System, including the Moon, Mars, and the large asteroid Vesta, has a distinctive signature of oxygen isotopes that can be recognized even when other factors, such as chemical composition and type of rock, are different."

...his team prepped tiny crumbs of these 11 meteorite fragments and loaded them into a reaction chamber where they were heated with a laser and underwent chemical reactions to release oxygen and then used another device, called a mass spectrometer, to measure the concentrations of these oxygen isotopes. Results showed that the full range of oxygen isotopes known to be present in ureilites were also present in the studied fragments.
"It was already known that the fragments in the Nubian Desert came from the same asteroid. Taking that into account, these new results demonstrate that the asteroid's source, the ureilite parent body, also had a diversity of oxygen isotopes," says Rumble.

The diversity of oxygen isotopes found in ureilites probably arises from the circumstances of the parent this body's formation. Rumble theorizes that the rock components of this parent body were heated to the point of melting and then cooled into crystals so quickly that the oxygen isotopes present could not come to an equilibrium distribution throughout....

"The exact cause of the problem is still unknown"

Here's a massive printing glitch, problems with paper feeds, that probably has happened to you.According to CNBC, U.S. government printing presses were unable to correctly feed new paper used to make $100 bills causing some notes to crease and create blank spaces on some of the bills. An unknown number of bills printed could be damaged so the entire batch of bills, 1.1 billion of them, will be unusable until someone figures out a way to sort the good ones from the bad. The exact cause of the problem is still unknown.


Above quote from zdnet which has nice pictures.

Is there an unknown companion to the Sun?

Is there a hidden companion to the sun? This idea sounds old-fashioned but now scientists think an object larger than Jupiter, may be orbiting on the edge of our solar system. This article is from Wired--I usually try to edit stuff out of these posts, so that it looks like fair use, but really, all the info seems distinct and important. Of course there are good reasons to visit the site that originated the news below. For one thing, a wonderful picture shows the Oort Cloud is outside the solar system, (what!!) so I may have really confused some stuff.
Check it out.

A century of comet data suggests a dark, Jupiter-sized object is lurking at the solar system’s outer edge and hurling chunks of ice and dust toward Earth.

“We’ve accumulated 10 years more data, double the comets we viewed to test this hypothesis,” said planetary scientist John Matese of the University of Louisiana. “Only now should we be able to falsify or verify that you could have a Jupiter-mass object out there.”

In 1999, Matese and colleague Daniel Whitmire suggested the sun has a hidden companion that boots icy bodies from the Oort Cloud, a spherical haze of comets at the solar system’s fringes, into the inner solar system where we can see them.

In a new analysis of observations dating back to 1898, Matese and Whitmire confirm their original idea: About 20 percent of the comets visible from Earth were sent by a dark, distant planet.

This idea was a reaction to an earlier notion that a dim brown dwarf or red dwarf star, ominously dubbedNemesis, has pummeled the Earth with deadly comet showers every 30 million years or so. Later research suggested that mass extinctions on Earth don’t line up with Nemesis’s predictions, so many astronomers now think the object doesn’t exist.

“But we began to ask, what kind of an object could you hope to infer from the present data that we are seeing?” Matese said. “What could possibly tickle [comets'] orbits and make them come very close to the sun so we could see them?”

Rather than a malevolent death star, a smaller and more benign companion called Tyche (Nemesis’s good sister in Greek mythology) could send comets streaming from the Oort Cloud toward Earth.

The cosmic snowballs that form the hearts of comets generally hang out in the Oort Cloud until their orbits are nudged by some outside force. This push could come from one of three things, Matese says. The constant gravitational pull of the Milky Way’s disk can drag comets out of their icy homes and into the inner solar system. A passing star can shake comets loose from the Oort Cloud as it zips by. Or a large companion like Nemesis or Tyche can pull comets out of their comfort zones.

Computational models show that comets in each of these scenarios, when their apparent origins are mapped in space, make a characteristic pattern in the sky.

“We looked at the patterns and asked, ‘Is there additional evidence of a pattern that might be associated with a passing star or with a bound object?’” Matese said.

After examining the orbits of more than 100 comets in the Minor Planet Center database, the researchers concluded that 80 percent of comets born in the Oort Cloud were pushed out by the galaxy’s gravity. The remaining 20 percent, however, needed a nudge from a distant object about 1.4 times the mass of Jupiter.

“Something smaller than Jovian mass wouldn’t be strong enough to do the deed,” Matese said. “Something more massive, like a brown dwarf, would give a much stronger signal than the 20 percent we assert.”

There’s one problem, however. The pattern only works for comets that come from the spherical outer Oort Cloud, which extends from about 0.3 to 0.8 light-years from the sun. Comets from the flatter, more donut-shaped inner Oort Cloud don’t create the same distinctive pattern.

“That’s troubling,” Matese said. “It requires an entirely new dynamical explanation for how inner Oort Cloud comets are made observable.”...

“I think this whole issue will be resolved in the next 5 to 10 years, because there’s surveys coming on line … that will dwarf the comet sample we have today,” he said. “Whether these types of asymmetries in the directions that comets are coming from actually do exist or not will definitely be hammered out by those surveys.”

We may not have to wait that long, Matese says. An object like Tyche could be seen directly by WISE, NASA’s infrared space telescope.
“We anticipate that this WISE is going to falsify or verify our conjecture,” he said. “We just have to be patient.”

Images: 1) Comet Sliding Spring, a visitor from the Oort Cloud, was captured by WISE in Jan. 2010. Credit: NASA/JPL-Caltech/UCLA 2) The layout of the solar system, including the Oort Cloud, on a logarithmic scale. Credit: NASA


S

Miniature galaxy with miniature black hole

The link here is to an article about what scientists are calling a galaxy within a galaxy. This phenomena (and perhaps it's location)  allows them to study features more common in the early universe. But I cannot relay it reliably, here are parts of the article, and you want to see the picture at the original article.

Following a study of what is in effect a miniature galaxy buried inside a normal-sized one - like a Russian doll - astronomers using a CSIRO telescope have concluded that massive black holes are more powerful than we thought.

An international team of astronomers led by Dr Manfred Pakull at the University of Strasbourg in France has discovered a 'microquasar' - a small black hole, weighing only as much as a star, that shoots jets of radio-emitting particles into space.

Called S26, the black hole sits inside a regular galaxy called NGC 7793, which is 13M light-years away in the Southern constellation of Sculptor.

Earlier this year Pakull and colleagues observed S26 with optical and X-ray telescopes...
Now they have made new observations with CSIRO's Compact Array radio telescope near Narrabri, NSW. These show that S26 is a near-perfect analogue of the much larger 'radio galaxies' and 'radio quasars'. ...

Powerful radio galaxies and quasars are almost extinct today, but they dominated the earlyUniverse, billions of years ago, like cosmic dinosaurs. They contain big black holes, billions of times more massive than the Sun, and shoot out huge radio jets that can stretch millions of light-years into space.

Astronomers have been working for decades to understand how these black holes form their giant jets, and how much of the black hole's energy those jets transmit to the gas they travel through. That gas is the raw material for forming stars, and the effects of jets on star-formation have been hotly debated.

"Measuring the power of black hole jets, and therefore their heating effect, is usually very difficult," said co-author Roberto Soria (University College London)...
"With this unusual object, a bonsai radio quasar in our own backyard, we have a unique opportunity to study the energetics of the jets."
Using their combined optical, X-ray and radio data, the scientists were able to determine how much of the jet's energy went into heating the gas around it, and how much went into making the jet glow at radio wavelengths.

They concluded that only about a thousandth of the energy went into creating the radio glow.

"This suggests that in bigger galaxies too the jets are about a thousand times more powerful than we'd estimate from their radio glow alone," said Dr Tasso Tzioumis of CSIRO Astronomy and Space Science.

"That means that black hole jets can be both more powerful and more efficient than we thought, and that their heating effect on the galaxies they live in can be stronger."
...
Publication: Roberto Soria, Manfred W. Pakull, Jess W. Broderick, Stephane Corbel, and Christian Motch. "Radio lobes and X-ray hotspots in the microquasar S26." In press in Monthly Notices of the Royal Astronomical Society. Available online on the MNRAS website and at http://arxiv.org/abs/1008.0394.