And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.
Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.
Typical massive galaxy at z=1.1 (left: V, I (Hubble); right: CO 3-2 mm emission (IRAM); copyright MPE/IRAM)
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Galaxies long, long ago were very fecund; they gave birth to stars at a rate at least ten times what we see today.
Why? Was there more stuff around then, to make stars? Or were galaxies back then more efficient at star-making? Or something else??
Dr. Linda Tacconi, from Germany’s Max-Planck-Institut für extraterrestrische Physik, led an international team of astronomers to find out why … and the answer seems to be that young galaxies were stuffed to the gills with gas.
“We have been able, for the first time, to detect and image the cold molecular gas in normal star forming galaxies, which are representative of the typical massive galaxy populations shortly after the Big Bang,” said Dr Tacconi.
The challenging observations yield the first glimpse how galaxies, or more precisely the cold gas in these galaxies, looked a mere 3 to 5 billion years after the Big Bang (equivalent to a cosmological redshift z~2 to z~1). At this age, galaxies seem to have formed stars more or less continuously with at least ten times the rate seen in similar mass systems in the local Universe.
It is now reasonably well-established that galaxies formed from proto-galaxies, which themselves formed in local over-densities, dominated by cold dark matter – dark matter halos – where the newly neutral hydrogen and helium collected and cooled. Through collisions and mergers, and some on-going gas accretion, the proto-galaxies formed young galaxies, a few billion years after the Big Bang – in short, hierarchical formation. The Plateau de Bure millimetre interferometer in the southern French Alps. Copyright: IRAM
Detailed observations of the cold gas and its distribution and dynamics hold a key role in disentangling the complex mechanisms responsible for turning the first proto-galaxies into modern galaxies, such as the Milky-Way. A major study of distant, luminous star forming galaxies at the Plateau de Bure millimeter interferometer has now resulted in a breakthrough by having a direct look at the star formation “food”. The study took advantage of major recent advances in the sensitivity of the radiometers at the observatory to make the first systematic survey of cold gas properties (traced by a rotational line of the carbon monoxide molecule) of normal massive galaxies when the Universe was 40% (z=1.2) and 24% (z=2.3) of its current age. Previous observations were largely restricted to rare, very luminous objects, including galaxy mergers and quasars. The new study instead traces massive star forming galaxies representative of the ‘normal’, average galaxy population in this mass and redshift range.
“When we started the programme about a year ago”, says Dr. Tacconi, “we could not be sure that we would even detect anything. But the observations were successful beyond our most optimistic hopes. We have been able to demonstrate that massive normal galaxies at z~1.2 and z~2.3 had five to ten times more gas than what we see in the local Universe. Given that these galaxies were forming gas at a high rate over long periods of time, this means that gas must have been continuously replenished by accretion from the dark matter halos, in excellent agreement with recent theoretical work.”
Another important result of these observations is the first spatially resolved images of the cold gas distribution and motions in several of the galaxies. “This survey has opened the door for an entirely new avenue of studying the evolution of galaxies,” says Pierre Cox, the director of IRAM. “This is really exciting and there is much more to come.”
“These fascinating findings provide us with important clues and constraints for next-generation theoretical models that we will use to study the early phases of galaxy development in more detail,” says Andreas Burkert, specialist for star formation and the evolution of galaxies at Germany’s Excellence Cluster Universe. “Eventually these results will help to understand the origin and the development of our Milky Way.”
About the EGS 1305123 image: Spatially resolved optical and millimeter images of a typical massive galaxy at redshift z=1.1 (5.5 billion years after the Big Bang). The left image was taken with the Hubble Space Telescope in the V- and I-optical bands, as part of the AEGIS survey of distant galaxies. The right image is an overlay of the CO 3-2 emission observed with the PdBI (red/yellow colors) superposed on the I-image (grey). For the first time these observations clearly show that the molecular line emission and the optical light from massive stars trace a massive, rotating disk of diameter ~60,000 light years. This disk is similar in size and structure as seen in z~0 disk galaxies, such as the Milky Way. However, the mass of cold gas is in this disk is about an order of magnitude larger than in typical z~0 disk galaxies. This explains why high-z galaxies can form continuously at about ten times the rate of typical z~0 galaxies.
No word yet from the Phoenix Mars Lander and, really, mission managers don’t expect to hear from the lander. But that doesn’t mean they aren’t trying. Teams are currently attempting to make contact, with another — and final — series of attempts that may occur next month.
“We haven’t heard a peep since late 2008, when a dust storm combined with the onset of winter to end the mission,” said Mark Lemmon from Texas A&M University, who worked with Phoenix’s camera. “But if Phoenix did survive, a revived mission could uncover some of the climate processes in the area around Mars’ North Pole, where most of the water seems to be.”
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Last contact with Phoenix was back in October 2008, and the teams that worked with the lander are holding out hope that some of the electronics on board survived the severe Martian winter, which dwarfs anything seen on Earth (even the Snowmageddons and Snowpocalypses). Temperatures fall to minus-180 degrees for months at a time and carbon dioxide ice likely engulfed the Phoenix lander. Still, Lemmon said he is ready to help take more pictures and analyze more data if the Lander can be restored to life.
“Phoenix accomplished its mission,” he said, “and it was never designed to survive a Martian winter. In winter, heavy amounts of carbon dioxide frost may have accumulated on its solar panels and it is possible they broke off. Without those panels, which give Phoenix its energy source, it’s pretty much powerless. In addition, other parts may have failed in the extreme cold.”
Phoenix landing site, August, 2009. Credit: NASA/JPL/U of Arizona. Annotations by Phil Stooke
The Phoenix Lander, which landed on Mars May 25, 2008, was designed to dig for soil samples and buried ice near Mars’ North Pole. It also studied Mars’ polar weather.
Phoenix returned more than 30,000 images and made several chemical analyses of the soil above the Martian permafrost. Those analyses found carbonate minerals in the soil, showed that the composition of the soil is near that of Earth’s oceans rather than being acidic, and found perchlorates, which are present in soils in Chile’s Atacama desert on Earth, where they are used as food by some species of bacteria.
Recent images from the Mars Reconnaissance Orbiter show frost in the area around Phoenix’s landing site is now dissipating. Last month, the Mars Odyssey spacecraft, which orbits the planet, made 30 attempts to contact Lander. All failed.
Lemmon says the Lander mission was a success by any measurement.
“The soil samples it dug up show several possible energy sources, such as perchlorates,” he adds, “and that discovery will have a big impact on future plans to explore Mars. The weather information Phoenix returned will be very useful in understanding Mars’ climate, and the discovery of water-ice snowfall near the end of the mission is still amazing.”
The ESA has scheduled the launch of Cryosat-2 for February 25th aboard a Russian Dnepr rocket from the Baikonur Cosmodrome in Kazakhstan. This is the second attempt at launching the Earth-observing satellite that’s tasked with monitoring global ice thickness. The initial launch of Cryosat on October 8th, 2005 failed due to an anomaly of the launch sequence.
Other Earth-observing satellites have taken measurements of the ice thickness near the poles, but Cryosat-2 will be the first such satellite completely dedicated to monitoring ice thickness variations, and will keep tabs on the decline of sea ice, which in the Arctic has been shown to have shrunk 2.7% per decade since 1978.
Cryosat-2 will have a highly inclined polar orbit, and will reach 88 degrees north and south, so as to maximize the amount of observations of the Earth’s poles. The instruments aboard the satellite will be able to monitor the thickness changes in both sea ice and land ice with an accuracy of one centimeter. This will give scientists an unprecedented amount of data to work with to study how Arctic and Antarctic ice changes impact climate change, and vice versa.
The instrument aboard Cryosat-2 that will be measuring ice thickness is the SAR/Interferometric Radar Altimeter (SIRAL). This is a an altimeter and interferometer that operates in the Ku-band (13.575 GHz), and uses radar signals bounced off the ice to measure its thickness variations.
Cryosat-2 also has two other instruments to determine its position with a high amount of accuracy, the Doppler Orbit and Radio Positioning Integration by Satellite (DORIS) and Laser Retro-Reflector (LRR). DORIS detects and measures the Doppler shift of signals broadcast from a network of radio beacons spread around the world to give the velocity of the satellite relative to the Earth.
The LRR instrument will complement and help calibrate DORIS. The LRR is a small laser retroreflector that is attached to the underside of the satellite, and lasers from a network of tracking stations will be fired at the satellite. By measuring the interval between the firing of the laser and the return of the pulse, the position of the satellite can be measured very accurately.
The mission has a three-year lifespan, with a potential for a two-year extension. Cryosat-2 is currently nestled safely inside the Dnepr rocket’s protective fairing, and in the next nine days the satellite will be integrated into the rest of the launcher and moved out to the launch pad.
The proton has three parts, two up quarks and one down quark … and the gluons which these three quarks exchange, which is how the strong (nuclear) force works to keep them from getting out.
The proton’s world is a totally quantum one, and so it is described entirely by just a handful of numbers, characterizing its spin (a technical term, not to be confused with the everyday English word; the proton’s spin is 1/2), electric charge (+1 e, or 1.602176487(40)×10-19 C), isospin (also 1/2), and parity (+1). These properties are derived directly from those of the proton parts, the three quarks; for example, the up quark has an electric charge of +2/3 e, and the down -1/3 e, which sum to +1 e. Another example, color charge: the proton has a color charge of zero, but each of its constituent three quarks has a non-zero color charge – one is ‘blue’, one ‘red’, and one ‘green’ – which ‘sum’ to zero (of course, color charge has nothing whatsoever to do with the colors you and I see with our eyes!).
Murray Gell-Mann and George Zweig independently came up with the idea that the proton’s parts are quarks, in 1964 (though it wasn’t until several years later that good evidence for the existence of such parts was obtained). Gell-Mann was later awarded the Nobel Prize of Physics for this, and other work on fundamental particles (Zweig has yet to receive a Nobel).
The quantum theory which describes the strong interaction (or strong nuclear force) is quantum chromodynamics, QCD for short (named in part after the ‘colors’ of quarks), and this explains why the proton has the mass it does. You see, the up quark’s mass is about 2.4 MeV (mega-electron volts; particle physicists measure mass in MeV/c2), and the down’s about 4.8 MeV. Gluons, like photons, are massless, so the proton should have a mass of about 9.6 MeV (= 2 x 2.4 + 4.8), right? But it is, in fact, 938 MeV! QCD accounts for this enormous difference by the energy of the QCD vacuum inside the proton; basically, the self-energy of ceaseless interactions of quarks and gluons.
There is not one, not two, not even three gravity equations, but many!
The one most people know describes Newton’s universal law of gravitation:
F = Gm1m2/r2,
where F is the force due to gravity, between two masses (m1 and m2), which are a distance r apart; G is the gravitational constant.
From this is it straightforward to derive another, common, gravity equation, that which gives the acceleration due to gravity, g, here on the surface of the Earth:
g = GM/r2,
Where M is the mass of the Earth, r the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant.
With its publication in the early years of the last century, Einstein’s theory of general relativity (GR) became a much more accurate theory of gravity (the theory has been tested extensively, and has passed all tests, with flying colors, to date). In GR, the gravity equation usually refers to Einstein’s field equations (EFE), which are not at all straight-forward to write, let alone explain (so I’m going to write them … but not explain them!):
G?? = 8?G/c4 T??
G (without the subscripts) is the gravitational constant, and c is the speed of light.
where a is the acceleration a star feels, due to gravity under MOND (MOdified Newtonian Dynamics), an alternative theory of gravity, M is the mass of a galaxy, r the distance between the star in the outskirts of that galaxy and its center, G the gravitational constant, and a0 a new constant.
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Galaxy names come in a bewildering range of forms; from descriptive (e.g. Whirlpool Galaxy, Black Eye Galaxy, The Eyes), to ones that seem to relate to a constellation (e.g. Andromeda Galaxy, Hydra A, Leo I), to ones named after a person (e.g. Stephan’s Quintet, Malin I, Mayall’s Object), to letter+number combinations (e.g. the Messier catalog galaxies such as M33 and M87), to letters+number combinations (e.g. NGC 3115, DDO 185), to impossible-to-remember stings-with-dashes-dots-and-pluses like MCG-06-07-001, 4C37.11, and SDSS J002240.91+143110.4!
And sometimes a galaxy has LOTS of different names, such as M87, Virgo A, NGC 4486, Arp 152, 3C274, IRAS 12282+1240, WMAP J123051+1223 (there’s, like, about another 20!).
However, of the estimated 100 billion galaxies we could observe, with current astronomical facilities, only a few million have names, and most of those are unique (i.e. only one name per galaxy). Of course, almost all the single-name galaxies are little more than faint smudges in an optical or infrared image … and that gives a clue to where the names come from!
Most galaxy names come from the catalog, or catalogs, in which they appear. The catalogs have many sources, but most recent ones have been put together as a key output of a dedicated survey or mission, and the galaxy name reflects that. So, for example, SDSS stands for Sloan Digital Sky Survey (one of the most amazing optical/NIR galaxy surveys of all time), IRAS for InfraRed Astronomy Satellite, DDO for David Dunlap Observatory (where a catalogue of dwarf galaxies was put together), and 4C for 4th Cambridge survey (a radio survey). Some of the older catalogs, or lists, were put together from previously known galaxies, or objects (the Messier list is perhaps the most famous example).
Seeing double? Darn right you are. It’s been awhile since I’ve featured any of Jukka Metsavanio’s brilliant visualizations… and things have gotten even more incredible since. Step inside and prepare to get blown away by “Stereo Soul”…
As always, whenever we present a dimensional visualization it is done in two fashions. The first is called “Parallel Vision” and it is much like a magic eye puzzle. When you open the full size image and your eyes are the correct distance from the screen, the images will seem to merge and create a 3D effect. However, for some folks, this doesn’t work well – so Jukka has also created the “Cross Version”, where you simply cross your eyes and the images will merge, creating a central image which appears 3D. For some folks, this won’t work either… But I hope it does for you!
Now, let’s learn a little bit about IC1848, the “Soul Nebula”…
Located about 6,500 light-years away in the constellation Cassiopeia, this complex of emission nebulae contain a radio source called W5. The stellar winds and intense radiation from the region’s most massive stars have carved out a black “holes” in the nebula. However, unlike the black holes that signal the death of a star, these forming cavities push the gases together and trigger new star formation. Younger stars line the rims of the cavities, while older ones form clumps and knots.
Let’s give them a fly-by…
Parallel Vision
Cross Vision
Can’t see “Stereo Soul”? Then have a look at this…
And be sure to thank J.P. Metsavanio for sharing his incredible visions with us!
Here are some beautiful galaxy pics. You can even use these as desktop background wallpapers if you like. Just click on an image to see a larger version and then right-click and choose “Set as Desktop Background”.
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This is a picture of a cluster of stars in the nearby satellite galaxy, the Small Magellanic Cloud. These bright young stars are blasting out a bubble of gas and dust with their powerful stellar winds.
Nucleus of Galaxy Centaurus A
This is a Hubble Space Telescope image of the nearby galaxy Centaurus A. The supermassive black hole at the heart of Centaurus A is currently feeding on a smaller galaxy that recently collided. Cosmic collisions like this were common in the early Universe, but they happen less frequently now with more space in between galaxies.
Supernova 1994D in Galaxy NGC 4526
This is a photograph of the galaxy NGC 4526, captured by the Hubble Space Telescope. You can also see a bright star below the galaxy; it’s not a star at all, but a supernova that was imaged as part of this photograph.
Galaxy Cluster MACS J0717
This is an image of the galaxy cluster MACS J0717 captured by NASA’s Chandra X-Ray Observatory. The image from Chandra lets astronomers see where large clouds of hot gas are colliding together, heating up to millions of degrees.
Hubble-Uncovers-a-Baby-Galaxy
This is an artist’s impression of what a galaxy might have looked like in the early Universe, just a billion years after the Big Bang. Stars formed out of the primordial hydrogen left over from the Big Bang, grew large and then detonated as supernovae, seeding the Universe with heavier elements.
A Murchison meteorite specimen at the National Museum of Natural History in Washington DC.
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New analysis of the famous Murchison meteorite that crash-landed in Australia over 40 years ago shows the space rock contains millions of previously unidentified organic compounds. Researchers say the meteorite, which is over 4.65 billion old – and likely older than our Sun — offers evidence that the early solar system likely had a higher molecular diversity than Earth, and may offer clues to the origins of life on our planet.
Pair of grains from the Murchison meteorite.
Philippe Schmitt-Kopplin from the Institute for Ecological Chemistry in Neuherberg, Germany and his colleagues examined the carbon-rich meteorite with high-resolution structural spectroscopy and found signals representing more than 14,000 different elementary compositions, including 70 amino acids in a sample of the meteorite.
Schmitt-Kopplin said that given the ways in which organic molecules with the same composition can be arranged in space, the meteorite should contain several million different organic chemicals.
The Murchison meteorite landed near a town of the same name in 1969. Witnesses saw a bright fireball which separated into three fragments before disappearing, leaving a cloud of smoke. About 30 seconds later, a tremor was heard. Many specimens were found over an area larger than 13 square km, with individual masses up to 7 kg; one, weighing 680 g, broke through a barn roof and fell in some hay. The total collected mass exceeds 100 kg.
Earlier analysis of the space rock revealed the presence of a complex mixture of large and small organic chemicals.
The meteor probably passed through primordial clouds in the early solar system, picking up organic chemicals. The authors of the paper suggest that tracing the sequence of organic molecules in the meteorite may allow them to create a timeline for the formation and alteration of the molecules within it.
