Their contributions were valuable to build one of the instruments of the space telescope to replace the Hubble and which could help detect biological signals on other worlds <. /> p>
Juan Rafael Martínez is a physicist at the National in Bogotá, did his thesis on stellar atmospheres at the Space Telescope Institute at Johns Hopkins. The master was made in the University of Leiden in the Netherlands, on early stages of star formation and doctorate right there in star formation in galaxies, while participating in the group of people who built and calibrated the instrument for the mid-infrared telescope James Webb Space, which is being assembled. In August 2012 he was sent to the United States, was at the end of the doctorate.
He returned to the United States, where it is 3 years at the Center for Astrophysics Harvard Smithsonian continuing research in the infrared, mainly doing research in star formation in colliding galaxies and star formation locally in the galaxy, using data from the Spitzer Space Telescope and Herschel.
There performed postdoctoral studies.
Her work has allowed increasing knowledge of star formation in galaxies, one of his areas of research.
Why look infrared?
For several reasons. Our eyes are limited to a range of light that can be seen with the naked eye and our optical telescopes and photographic plates seen our particular range of the spectrum. But if the distribution of energy in the universe look, how much energy comes in every color of the electromagnetic spectrum, including X-ray and radio, there are two large maximum energy. One is in the optical and other large maximum energy in which objects in the universe emit infrared and is almost half the energy of the universe comes in infrared and therefore have to explore the region. But it is also clear to much of the interstellar material in the optical prevents us from seeing beyond the star-forming regions that are completely buried in areas of dust and gas, the infrared through the clouds and allowed to study in more detail penetrating to loa deep where these clouds are forming new solar systems, new planets, etc.
A third reason is that infrared is enabling us to understand the formation of the first stars, the first galaxies in the history of the universe. In the very early universe’s first stars after a dark age in which hydrogen atoms were everywhere but had not made light sources like stars and galaxies formed. Sometime this happens and these galaxies began to shine in mainly ultraviolet light, which is light emitted by the young, massive stars; however as the universe is expanding, what happens is that these wavelengths expand and redden, become red, looking in the infrared is the only way we can see that original light of these galaxies. “
What about this look has come far?
“It has gone too far, as there are observations with Hubble and Spitzer have managed to see galaxies that were formed when the universe was very, very young, 13,000 million years ago. However it is not possible to check if indeed these galaxies are primeval galaxies because the way the starlight we see with current telescopes you may have contribution of older stars are distributed, they say, are not the first generation of stars, and Only when we look in the infrared that energy spectrum of these early stars can fully assess and then we have the confirmation that yes were the first galaxies. “
What have been your main achievements?
“My research has focused on studying what properties are globally star formation in galaxies. There are much more active galaxies form stars that our galaxy, which is on average one solar-like star every year. There are galaxies that formed 100 or 1000 type stars sunshine each year and is one of the questions of modern astrophysics is to understand how that process happens.
My work has focused on combining infrared observations and all the electromagnetic spectrum observed are interacting galaxies real because we believe that this process of interaction generates the physical, much interstellar material to be towards the galactic center and creates the conditions for star formation efficiency.
My job, and one of the recent achievements published, it is to study the actual observations combined with computer simulations of interacting galaxies and try to determine exactly what drives this process. And we have found that by colliding two galaxies efficiency of star formation increases the level we need to be increased to account for these rates of formation in very distant galaxies that are very efficient in star formation.
We published a study in the Astrophysical Journal in which we understand to some extent why the galaxies in the universe form stars intermediate as efficiently and has to do with the process of colliding galaxies.
My other great achievement has been my participation in the mission of the large telescope James Webb. I was able to shove his hands the instrument that will make those discoveries that will have a camera and a spectrograph that will unlock the secrets of star and planet formation in the nearby universe and of these early galaxies.
It was thanks to my doctoral work we calibrate the instrument, the spectrograph wavelength, we found that the spectroscopic properties of the instrument were expected to science it needs.
These have the major achievements in the race. “
What can you expect from the James Webb?
” You never know what to expect. These missions are designed with specific objectives, are more to convince those who will finance the mission. That is part of big questions we have, such as how the first galaxies were assembled, how planetary systems are formed like ours, how likely find life in them. James Webb will certainly have a major role in unravel, but the most exciting Space Telescope is something we do not know that we will provide. It has happened with the Hubble, the Spitzer, for example the accelerating expansion of the universe was a discovery that was not expected when they launched the Hubble but as they began to make measurements of increasingly distant supernovae were able to understand the universe is not only expanding but accelerating its expansion. It was a discovery for which it was designed. The same hope for the James Webb.
It will probably be the first instrument that will systematically characterize the atmospheres of extrasolar planets and will allow you to see if there are some items that can only explain biological processes and surely also the characterization of the first light sources in the universe. “
What regions near the solar system have intense star formation?
” We are in a relatively peripheral region of the galaxy. There are regions where the spiral arms are coupled with the central bar by the dynamics of the galaxy converges much gas there and material makes it particularly violent in star formation. One example is Cygnus X region, where conditions can be very similar to many regions of galaxies where stars form, but it is a very small region. A known and nearby object is the Orion Nebula, star-forming region is not extremely massive, but have formed there massive stars recently that are illuminating the nebula. “
The rate of star formation is much lower today …
“There was a time in the history of the universe to the cosmic star formation peaked and now that rate is declining and of the questions it is why: Why did that at a time the universe was given to form stars and why has declined. It is probably related to the time of assembly of galaxies collided very often and had a large amount of gas. “
Will it continue like this?
” That It depends somewhat on what the ultimate fate of the universe. The best cosmological models and settings suggest that the universe will continue to expand and become less dense and therefore the probability of these large galactic collections resurgence is apparently low. We bet that the universe will continue to decrease its rate of star formation. There are even those who believe in a heat death of the universe, a moment in which there are no more star formation because the material is very diffuse. But we do not have the last word and who knows if at some point we discovered that gravity will overtake the dark energy that makes the universe expand. But today it seems that tends to expand more. “
So is less frequent clash of galaxies?
” Right, galaxies are increasingly further each other. Still happen but at a slower rate than previously.
The Milky Way has a satellite galaxies, dwarf galaxies around 100,000 stars, the orbits eventually lead to a collision, which would be more than the Milky Way finished swallowing them. The biggest event would be the collision with Andromeda, but are isolated events, are not the norm. They were the norm in the cosmic noon, when collisions were more frequent.
What happens in a collision?
“From the point of view of the stars do not spend much. It is thought to be a catastrophe, but the probability that two stars touch in the collision is very low. The stars are separated by considerable distances. What may happen is that radiation is increased because there will be more density of stars, may be the closest not to 4 light years but half a light year, there will be more supernovas near wholesale star formation, but timescales billions of years, it’s not something to worry about. “
What would happen to the black holes in each galaxy?
” What we do with the simulations is to see how these processes and as galaxies collide, they come, they go close, the pull of gravity, again approaching and finally mixed. Each galaxy has a supermassive black hole at the center, they are also mixed into one that produces the active galactic nuclei, sucks all the material in the vicinity and produce much radiation that heats the interstellar dust that emits infrared light, or when we are looking at a galaxy in the infrared we are not only looking at the interstellar dust it is being heated by the star formation process but also in many cases by radiative processes the nearby black hole.
And it is difficult to separate how much of the emission of infrared light comes from each source. “
What triggers the star formation process?
” It’s a good question It is difficult to answer. We tend to believe that the process is the same. It also seems to depend on the mass of the stars. Interstellar gas and gravity, enough material needed to form what will be the fuel of this star and gravity does collapse, these conditions are very good in galactic collisions and in some regions of galaxies by the internal dynamics. But what happens when the star is formed? When very young will produce a feedback to the medium by its radiation, its light with high energy photons. The form can influence the formation of future stars, to form a mass will push the interstellar medium and that can have two opposite effects: either by pushing the middle it becomes more diffuse and makes it impossible for most stars or pressure forming, if there are other interstellar wind in the opposite direction you can do it is to compress the gas and produce more stars. It may be a chain drafting. That we are studying. It is an open question. “
more giant, massive? stars are
” One thing is the initial mass function, the stars form with a certain probability according to its mass, the most massive form with less probability than less massive. A star like the Sun is very likely to form and as Vega or Aldebaran is less likely, but these ones are the ones that dominate the process of radiation. When we look at regions of star formation we’re looking at is the light of these massive stars in number are less likely to find, but completely dominate energy. And he is looking at that kind of stars that determined the recent star formation. Because they are so massive, they consume their fuel faster and die on timescales of 10 million years, which is nothing in the life of a star like the sun. By looking at them means that the group was formed only 10 million years ago. ”
How is the agreement with the University of Laiden?
“The Astronomical Observatory of the University of Laiden is one of the oldest in the world, still in operation with a fabulous astronomical tradition that includes Lorentz, Oort and Kuiper today it is very active in research especially in star formation and galaxy, etc. Leaving the doctorate wanted to establish contact with an institution here and the most relevant was the U. of A. for its undergraduate. So in the last 3 years we have had teachers who come and dictate Laiden relatively advanced courses for Astronomy career that would otherwise inaccessible astronomy. And talks Explore dictate. “
Should there be more undergraduate Astronomy?
” There should be more astronomy, no doubt. We need more and more students may not necessarily, maybe the undergraduate grow in Antioquia, should eventually grow and perhaps other institutions, but I think that in Colombia we must also focus on providing opportunity to those students leaving the race either to astronomy research here, as there is a small gap between the training of university undergraduate and research. Do very well prepared students are not but go outside to investigate. It should grow that part first with the creation of a master, or more doctorates, while maintaining the numbers according to what our community and as a nation needs demand it, but obviously you have to focus a little research. When this occurs new teachers and new skilled people in different fields who are in Colombia would camp there for the student community to expand.
Colombia needs to invest more in Astronomy that not only produces beautiful pictures and beautiful stories but produces a lot of technology in astronomical instrumentation, is a source of social inspiration at all levels, not surprisingly Unesco and IAU have used it as an engine of development in developing nations because it not only produces science fascination and conscience of humanity to be part of something sublime and surely has a big impact on the way young people start to think of nations, the universe, etc.
And especially in Colombia because Now the eyes of the world are on Astronomy Colombia, next year we will be the largest gathering of the continent in Cartagena and Colombia today is the regional hub for the development of astronomy in the Andean region UAI initiative, and increasingly Astronomers international visitors. It is a propitious to give a boost to a science that can drive growth in other sciences and other aspects of development and innovation in the country “moment.
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