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FOR A E ST T R U O No. 47 • 2013 T I N T O O S M M A Newsletter from the N N I I Y Y Institute for Astronomy U ‘ i n i i a ve w Na¯ Kilo Ho¯ku¯ University of Hawai‘i rsit f Ha THE ONES WHO LOOK TO THE STARS y o Black Holes Were Abundant among Earliest Stars By comparing infrared and X-ray background signals across the same stretch of sky, an international team of astronomers, including IfA Director Günther Hasinger, has discovered evidence of a significant number of black holes that accompanied the first stars in the Universe. Using data from NASA’s Chandra X-ray Observatory and NASA’s Spitzer Space Telescope, which observes in the infrared, the team concluded one of every five sources contributing to the infrared signal is a black hole. “Our results indicate black holes are responsible for at least 20 percent of the cosmic infrared background, which indicates intense activity from black holes feeding on gas during the epoch of the first stars,” said Alexander Kashlinsky, an astrophysicist at NASA’s Goddard Space Flight Center. The cosmic infrared background (CIB) is the collective light from an epoch when structure first emerged in the Universe. Astronomers think it arose from clusters of massive Art by Karen Teramura suns in the Universe’s first stellar generations, as well The Cosmic Microwave Background (shown on left), as black holes, which produce vast amounts of energy the earliest light we can see, is from the hot, dense as they accumulate gas. Universe after the Big Bang. This was followed by the Join us for our upcoming Dark Ages, when there were no sources to produce light. Even the most powerful telescopes cannot see the Ma¯noa special event with Later, the first stars and black holes formed. While we most distant stars and black holes as individual former astronaut Ed Lu. can't see these individually, their collective light is seen sources. But their Please see Black Holes, pg 2 For ticket information, see in the cosmic infrared and X-ray backgrounds. Upcoming Events on page 7. Martian Meteorite Contains RNA Precursor Researchers from the University of Hawai‘i NASA DNA,” said James Stephenson, a UHNAI postdoctoral Astrobiology Institute (UHNAI) have discovered high fellow. concentrations of boron in a Martian meteorite. When RNA may have been the first molecule to store present in its oxidized form (borate), boron may have information and pass it on to the next generation, a What’s Inside played a key role in the formation of RNA, one of the mechanism crucial for evolution. Although life has building blocks for life. Video Universe pg 3 now evolved a sophisticated mechanism to synthesize The Antarctic Search for Meteorites team found RNA, the first RNA molecules must have been made Zahid ARCS Award pg 3 the Martian meteorite used in this study in Antarctica without such help. One of the most difficult steps in during its 2009–2010 field season. The minerals it making RNA nonbiologically is the formation of the HI STAR pg 4 contains, as well as its chemical composition, clearly RNA sugar component, ribose. Previous laboratory Comet ISON pg 5 show that it is of Martian origin. Using the ion tests have shown that without borate the chemicals microprobe in the W. M. Keck Cosmochemistry available on the early Earth fail to build ribose. Are We Alone? pg 6 Laboratory at UH, the team was able to analyze veins However, in the presence of borate, ribose is of Martian clay in the meteorite. After ruling out spontaneously produced and stabilized. Ed Lu’s talk pg 7 contamination from Earth, they determined boron This work was born from the uniquely From the Director pg 8 abundances in these clays are over ten times higher interdisciplinary environment of UHNAI. The lead than in any previously measured meteorite. authors on the paper, Stephenson, an evolutionary “Borates may have been important for the origin of biologist, and Lydia Hallis, a cosmochemist who is also The University of Hawai‘i life on Earth because they can stabilize ribose, a a UHNAI postdoctoral fellow, first came up with the is an Equal Opportunity/ crucial component of RNA. In early life, RNA is idea over an after-work beer. “Given that boron has Affirmative Action Institution. thought to have been the informational precursor to been implicated Please see Martian Meteorite, pg 2 Black Holes Continued from page 1 combined glow, traveling across billions of light-years, observations, lead researcher Nico Cappelluti (National allows astronomers to begin deciphering the relative Institute of Astrophysics, Bologna, Italy, and University contributions of the first generation of stars and black of Maryland, Baltimore County), produced X-ray maps holes in the young cosmos. This was at a time when with all of the known sources removed in three dwarf galaxies assembled, merged, and grew into wavelength bands. The result, paralleling the Spitzer majestic objects like our own Milky Way galaxy. “We studies, was a faint, diffuse X-ray glow that constitutes wanted to understand the nature of the sources in this the cosmic X-ray background (CXB). era in more detail, so I suggested examining Chandra Comparing these maps allowed the team to data to explore the possibility of X-ray emission determine whether the irregularities of both backgrounds associated with the lumpy glow of the CIB,” said fluctuated independently or in concert. Their detailed Hasinger. study indicates fluctuations at the lowest X-ray energies The work began in 2005, when Kashlinsky and his are consistent with those in the infrared maps. “This colleagues studying Spitzer observations first saw hints measurement took us some five years to complete and of a remnant glow. The glow became more obvious in the results came as a great surprise to us,” said further Spitzer studies by the same team in 2007 and Cappelluti. 2012. The 2012 investigation examined a region known The process is similar to standing in Los Angeles as the Extended Groth Strip, a single well-studied slice of while looking for signs of fireworks in New York. The sky in the constellation Bootes. In all cases, when the individual pyrotechnics would be too faint to see, but scientists carefully subtracted all known stars and removing all intervening light sources would allow the galaxies from the data, what remained was a faint, detection of some unresolved light. Detecting smoke irregular glow. There is no direct evidence this glow is would strengthen the conclusion that at least part of this extremely distant, but telltale characteristics lead signal came from fireworks. In the case of the CIB and researchers to conclude it represents the CIB. CXB maps, portions of both infrared and X-ray light seem In 2007, Chandra took especially deep exposures of to come from the same regions of the sky. The team the Extended Groth Strip as part of a multiwavelength reports black holes are the only plausible sources that survey. Along a strip of sky slightly larger than the full can produce both energies at the intensities required. moon, the deepest Chandra observations overlap with Regular star-forming galaxies, even those that vigorously the deepest Spitzer observations. Using Chandra form stars, cannot do this. Martian Meteorite from page 1 in the emergence of life, I had assumed that it was well characterized in meteorites,” said Stephenson. “Dis- cussing this with Dr. Hallis, I found out that it was barely studied. I was shocked and excited. She then informed me that both the samples and the specialized machinery needed to analyze them were available at UH.” On our planet, borate-enriched salt, sediment and clay deposits are relatively common, but such deposits Above: Thin section have never previously been found on an extraterrestrial of the Martian body. This new research suggests that when life was meteorite MIL getting started on Earth, borate could also have been 090030 analyzed by concentrated in deposits on Mars. the UHNAI The significance goes beyond an interest in the red researchers. planet, as Hallis explains: “Earth and Mars used to have Right: Electron much more in common than they do today. Over time, microscope image Mars has lost a lot of its atmosphere and surface water, showing the but ancient meteorites preserve delicate clays from The presence of ancient borate-enriched clays on 700-million-year-old wetter periods in Mars’ history. The Martian clay we Mars implies that these clays may also have been Martian clay veins studied is thought to be up to 700 million years old. The present on the early Earth. Borate-enriched clays such as containing boron recycling of the Earth’s crust via plate tectonics has left the one studied here may have represented chemical (100 µm = one tenth no evidence of clays this old on our planet; hence havens in which one of life's key molecular building of a millimeter). Martian clays could provide essential information regarding environmental conditions on the early Earth.” blocks could form. 2 This map shows the flows of galaxies in the Universe. The galaxies (white spheres) are like dead branches in a sea. Currents carry them from an island (galaxy cluster) to the closest larger island of galaxies, the Great Attractor region. Red and yellow colors show the islands, and dark A Video Map of Motions in the Nearby Universe blue shows the voids The Universe is a dynamic place, as the video, total matter of our Universe and is the main cause of that galaxies avoid by following the currents. Cosmography of the Local Universe, demonstrates.

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