Scientists from the Max Plank Institute for Radio Astronomy in Bonn Germany using NASA’s Fermi Gamma Ray Space Telescope and the world’s largest radio telescope array have solidified a theoretical link between radio jets coming from the center of active galaxies and gamma ray bursts. This is a fine demonstration and use of new technology combined with an innovative use of existing technology.

Active galaxies are extremely bright galaxies which emitted oppositely directed jets of charged particles from their centers traveling near the speed of light.  Some, called Blazars, are especially bright because their jets are orientated along our line of sight.  These jets glow brightly in the radio part of the spectrum and in the 90’s it was hinted with the Chandra X-ray Observatory that they might emit in the higher energy parts of the spectrum as well. Astronomers believe these jets arise from matter that is falling into the central massive black holes of the galaxies, but the exact processes behind them is not well understood; which makes them the object of much study.

Now the Fermi telescope uses it’s Large Area Telescope, LAT, to scan the entire sky every 3 hours getting snapshots of the gamma ray bursts throughout the sky and monitor flares. Gamma ray bursts are the highest energy form of light below cosmic rays, and the origins of these gamma ray bursts is still undetermined; the objective of Fermi is to help clarify these origins. 

The new study was part of the MOJAVE program, which is a long-term study of the jets form active galaxies using primarily the VLBA. The VLBA is the National Science Foundation’s Very Long Baseline Array, a set of 10 radio telescopes located from Hawaii to the Virgin Islands and operated by the National Radio Astronomy Observatory in New Mexico.  Signals from these 10 different telescopes are combined and the array acts like a single enormous radio dish more than 8,500 kilometers across. The VLBA can resolve details about a million times smaller than Fermi and50 times smaller than any optical telescope.

Astronomers combined data from the VLBA and LAT. Active galaxies detected in the LAT’s first few months of operations generally possess brighter and more compact radio jets than galaxies the LAT did not see. Moreover, an active galaxy’s radio jets tend to be brighter in the months following any gamma-ray flares observed by the LAT.  A correlation was also found between active galaxies with the brightest gamma ray emission and those with the fastest jets.

The scientists were also able to use this data to study a phenomenon known as Doppler boosting. Doppler boosting makes radio-emitting blobs look brighter and appear to move faster than the speed of light due to the angle at which it is viewed and the fact the speed of the particles is close to the speed of light.  The VLBA data shows that the bigger the Doppler boost seen in a radio jet, the more likely it is that Fermi recorded it as a gamma ray source. Also, many objects found by Fermi to be extreme in gamma rays are broadcasting strong bursts of radio emission at the same time. 

All of this data points to the conclusion that the portion of an active galaxy’s radio jet closest to the galaxy’s center is also the source of the gamma rays.  These findings show us a very interesting and before unknown link between two “sides” of one object and possibly one process. This may bring astronomers one-step closer to solving two very large mysteries: the processes behind the jets and the exact processes or origins of gamma ray bursts. It could turn out to be quite nice and convenient if both questions could have the same answer, or an answer that comes from the same place. This new finding is also a demonstration of the use of the new technology of Fermi the space telescope that was designed just to study gamma ray bursts, a first of its kind, and the technology behind the VLBA, using standard radio telescopes in a new way to improve their usefulness. 

The largest mirror ever to be launched into space now has a set launch date.  The European Space Agency’s Herschel Space Observatory and Planck Satellite are set to launch into space May 6^th. . Together these two pieces of equipment should be bringing in lots of new and exciting information about our own solar system and distant galaxies.

Sir Frederick William Herschel was a German born British astronomer from the 18^th and 19^th century. He was most famous for discovering the planet Uranus and discovering infrared radiation.  The Herschel Space Observatory will be the first to cover the full far infrared and sub-millimeter telescope.  The large mirror measures in at 3.5 meters; it’s a novel and advanced concept using 12 silicon carbide petals brazed together into a single piece. It is one of the major technological highlights of the mission.  Herschel will be investigating a large array of astronomical objects including: galaxy formation in the early universe and galaxy evolution, star formation and its interaction with the interstellar medium, chemical composition of atmospheres and surfaces of solar system bodies, and molecular chemistry across the universe.  Sounds like it has it work cut out.

The Planck Satellite will be going up with Herschel Observatory.  The satellite is named after the famous German physicist Max Planck who is considered the founder of quantum theory.  The satellite was designed to observe the anisotropies of the cosmic microwave background radiation, or CMB, over the entire sky using high angular resolution.  The mission is meant to improve upon the data collected from the well-known WMAP mission and will be used to test theories of the early universe and the origin of cosmic structure. 

Herschel and Planck will start their journey in space on board an Ariane 5 departing from Europe’s Spaceport in Kourou, French Guiana. Final preparations for the launch are now being made such as fueling the two satellites and filling Herschel’s cryostat (a vessel used to maintain cryogenic temperatures) with helium.  Once launched the two satellites will separate and be put into separate orbits around the second lagrangian point of the earth-sun system, a distance of about 1.5 million km’s from Earth.  Both satellites are part of the European Space Agency’s Horizons 2000 Scientific Programme, which consisted of about 15 satellite or telescope projects over the last 20 years including such other projects as Cluster, Huygens, XMM-Newton, and others.

The launch of these two satellites/observatories is exciting. They are new and advanced pieces of technology aimed at answering some large questions in astronomy today.  And are a fine example of astronomy goals and projects outside of the US.  So for now we just have to keep our fingers crossed and hold our breath for a successful launch and problem free start up. 

Observational astronomers, engineers, and telescope experts are always working hard to better their observational equipment.  Even with all of our advanced technology when looking at things at such great astronomical distances we are still limited. However, recently astronomers in Germany made a break through with a new technique for improving resolution power of telescopes, allowing us to see previously unseen objects or resolve new details of known objects.

A team of astronomers, led by Stefan Kraus and Gerd Weigelt from the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany, used European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI) to obtain the sharpest image of the young double star Theta 1 Orionis C in the Orion Trapezium Cluster.  The Theta 1 system is a massive binary system of young stars in the Orion star-forming region. In previous images of the system, even with the Hubble Space Telescope, the telescopes were not able to resolve the two separate stars in the system, which are only separated by a distance of about 20 milliarcseconds.  The team was also able to derive the properties of the system including the masses of the two stars, about 38 and 9 solar masses, and also an accurate measure of the distance to the system, about 1350 light years.

The increase in resolution power came from using the technique of interferometry.  This method allows one to combine light collected from several telescopes, making what is like a “virtual” telescope with a resolving power equal to that of a ground based telescope with a 200 meter mirror or a space based telescope with a 130 meter mirror.  The Very Large Telescope now allows European astronomers to reconstruct images from the interferometric infrared data with the use of its near infrared beam combination instrument AMBER.  This gives the astronomers a resolving power of about 2 milliarcseconds.

Early imaging interferometry was almost exclusively done with long wavelength radio telescopes because the longer the wavelength of incoming radiation the easier it is to measure the phase information of data. Examples of radio interferometers are the Very Large Array, or VLA, and The Multi-Element Radio Linked Interferometer Network, or MERLIN. As the speeds of correlators and associated technologies have improved, the minimum radiation wavelength observable by interferometry has decreased. Now this is the first time astronomers have been able to use this technique with the shorter wavelength of infrared.

So far this technique with the VLIT has only been used to study Theta 1 in the Orion region.  The results obtained will be important for studying the Orion region and for theoretical models of massive star formation, as Theta 1 is a particularly massive and young star in an active star forming region.  Beyond the Orion data this method for observing promises to yield new discoveries and information about many different objects and topics. It is quite exciting innovation bringing us closer to new information without the need for necessarily spending much more time and money on new equipment. 

It has been observed for some time now that most large galaxies have super massive black holes at their center. It is generally believed that all galaxies have a central black, but some have thought for a while now that large galaxies may have more than one central black hole.  However, until very recently a binary black hole system had never been observed.  Astronomers from the National Optical Astronomy Observatory, NOAO, in Tucson AZ have found what they believe is the first binary system of two massive black holes.

The astronomers from NOAO used data from the Sloan Digital Sky Survey, SDSS, to look at quasars billions of light years away. More than 100,000 quasars are known while the astronomers for this study looked at 17,500 quasars from SDSS data.  A quasar is a quasi-stellar radio source; a powerfully energetic and distant galaxy with an active nuclei. They are hundreds of times brighter than our own galaxy and powered by matter falling into the black hole, or accreting, and as the matter falls in it heats up dramatically causing a luminous glow.

Astronomers are able to use “see” the central black hole by looking for a particular signature in the radiation coming from the in falling matter.  Now with two central black holes they would be too close together to actually distinguish their own accretion disks however there should be a characteristic dual signature in the emission lines.  It was this distinct signature that NOAO astronomers were looking for, and believe they have found.

Once the signature was detected the scientists had to rule out the possibility that it was coming from two separate galaxies in the same line of sight superimposed on each other. It took some work but they were able to determine that the emissions were coming form the same distance with only one possible host galaxies.  The double set of broad emission lines is pretty conclusive evidence that what was being seen is a binary black hole system. The smaller of the two black holes is estimated at about 20 million solar masses while the larger one is about 50 times bigger, as determined by their orbital velocities. 

This is an exciting discovery as it is the first of its kind. Further study can be used to research theories on galaxy mergers, super massive black hole evolution, and theories on gravity and relativity. It is theorized that galaxy mergers happen frequently and if each galaxy had a central black hole a merger would create a binary like this one. This theory also predicts that the two black holes will eventually merge themselves, evidence of which should, if theory is correct, be observable within the next few years. Also this is an ideal place to study theories of gravity and relativity, as the gravitational pull from a massive black hole binary system would be so strong gravitational effects not normally observable would be present.  It should be quite interesting to see what research and information comes from further study of this system.