Simulation answers the questions about spirality of Milky-way's arms

Christopher W. Purcell, postdoctoral research associate in the Department of Physics and Astronomy in Pitt's School of Arts and Sciences, and his colleagues have reported their observations in a paper, on September 15. They have reported that the spirality is a result of  the impact of Sagittarius Dwarf  during the early stages of the universe.

Supercomputers are generally used by the astrophysicists to produce a small scale simulation of what might have happened to the particular body in it's earlier stages of life. Then they would speed up the time and observed the simulated model to make further predictions of what might have happened during the course of it's life. Finally the results will be tested, observing the present universe. I hope now you understood what these simulations have got to do in our present context.
In the simulations, Purcell ended up finding two interesting things. One about the stars of the Sagittarius dwarf and other about the dark matter present in the dwarf. Our earlier observations using infrared telescopes in 2003 reported that the Dwarf had collided with the Milky-way twice as of date. Purcell says that theirs is the first ever to find out the effects of this impact on our galaxy.
Purcell says, "When all the dark matter smacked into the Milky Way, 80 to 90 percent of it was stripped off,". He added that this was when the first impact took place. He explains the spirality of the arms of Milky-way galaxy as follows: our galaxy rotates faster towards its center than towards it's edges. As a result, the instabilities were stretched and ended up forming spiral arms. The simulations conclude that by the time the second impact took place, the dwarf had completely lost it's dark matter and thus leaving free all the stars in it which then were pulled apart by the Milky-way's gravitational force.
Interesting thing about this whole story is the researches found out that the galaxy will be subjected to another impact by the next 10 million years. When asked about this Purcell said, "Immediately on the opposite side of us, we can see this blob of stars crashing into the southern face of the disc from beneath. We can measure the velocities of these stars. We know that the dwarf galaxy is just about to smash the disc—in only another 10 million years.". Lol you might be laughing after listening the left over time but let me tell you, the thing here is how appreciable the works are !! Congrats to the team and stay glued, more news about this yet to come .


Ref: eurekalert
September 15, 2011.

Pranu :-)

1 more Low-mass Extra Solar Planet

The European astronomers finally ended up with discovering a low mass extra solar planet, which was named as HD 85512b. It is discovered using the HARPS ( High Accuracy Radial Velocity Planet Searcher), at the European Southern Observatory's (ESO) location in La Silla, Chile. This is in the constellation Vela and is found to orbit around a star at 36 million light years away from the Earth. This planet is about 3.6 times in mass to that of the Earth, completing it's orbit around it's star within 60 days. The scientists are using a method of reflectivity to find out the reflection of the energy by the surface of the planet and more the reflection would simply imply more possibility of the planet having cloudy atmosphere. Lisa Kaltenegger, an astronomer with Max Planck Institute for Astronomy, Heidelberg, Germany says, "If we are really, really lucky, this planet could be a habitat comparable to Earth. This is a very exciting planet because if it is rocky, it will be the second confirmed planet that is within the habitable zone of its star,". Best noticeable thing out of all is that the planet is expected to have a temperatures around 30 to 50 degrees centigrade, which is an awesome thing if you can really understand !! Future studies are promised to test the nature of the planet; rocky or gaseous or anything else and as usually, as it comes to these Extra solar planets, am quite curious about the further results. Well, I seriously wish it has a rocky surface !!


Ref: ib times
September 14, 2011.

Pranu :-) 

Australia @ Astrophysics with the new CAASTRO

The all new CAASTRO (Centre of Excellence for All-sky Astrophysics) is launched today in Australia. The centre will deal with the major unsolved questions of Astronomy. Professor Bryan Gaensler from the School of Physics at the University of Sydney is the Director of the CAASTRO. Today, on the occasion of the launch of this new centre, Bryan answered to some of the questions posed by the media.

The whole system would revolve around the concept that many of the questions related to Astronomy can be solved only when we look at the sky as the whole. This is what they meant by that "All-sky Astrophysics". Bryan says that they will study on 3 main areas: Evolution, Dynamic Expansion and Dark Part of the Universe. When asked about the instruments they are going to use as a part of this new mission, he said, "You have to have telescopes that have very high quality, crisp, detailed images like Hubble but which have much wider fields of view". Regarding the budget, he announced that they have a seven year budget (of just over $4 million a year).The University of Sydney, the Australian National University, the University of Melbourne, the University of Western Australia, Curtin University and Swinburne University of Technology are the places from which the researchers are going to take part in this Centre. Anyways , lets wait and see if the Australians are going to be the ones answering the prominent and ultimate questions of Astronomy.

Ref: The Conversation
September 12, 2011.

Pranu :-)

Kepler 19c...Fake or Real?

Kepler 19b, the Earth like planet is doubted to have an invisible world exerting force on it. But no visible evidence is yet found. Kepler's spacecraft traces the details of the planets those pass by. The same spacecraft has found the orbit of Kepler 19b around it's star delays by about 5 minutes. This made the world doubt if there is an other invisible world which is exerting force on this Kepler 19b. This is not all but astronomers named it as Kepler 19c. Astronomer Sarah Ballard of the Harvard-Smithsonian Center for Astrophysics says, "This invisible planet makes itself known by its influence on the planet we can see,". Once found, the things may turn out very crazy, as happened with the Neptune, which has been found by studying the unknown force acted upon the Uranus. Even the gravitational force exerted by this unknown world on the Kepler 19b is also very less, which is leaving us helpless in calculating the mass, at least. Co-author Daniel Fabrycky of the University of California, Santa Cruz says, "Kepler-19c has multiple personalities consistent with our data. For instance, it could be a rocky planet on a circular 5-day orbit, or a gas-giant planet on an oblong 100-day orbit,". I wish this is going to turn out into an amazing piece of study and anyways, Stay glued for more updates :)


Ref: Science 20
September 10, 2011

Pranu :-)

2 Days to go @ Supernova

Peter Nugent, the senior scientist at Lawrence Berkeley National Laboratory spotted an exploding star in the Pinwheel Galaxy. 2 days more to have the best view of the supernova SN 2011fe. Its going to be September 12 when the Supernova is going to reach the maximum explosion and star the night! Wondering what's behind this Supernova getting publicized so much? Well, I've picked up 2 very good reasons for this: one is its just 25 million light years away from us and the other, its earlier spotting. Nugent says," the supernova is getting brighter by the minute, and increasing in brightness by sixfold each night". One more good news for Amateurs is no fancy or NASAian telescopes are needed to observe this. A pair of high resolution binoculars or a 3 inch long normal telescope would actually suffice. The very first thing you have to do is spot the pinwheel galaxy and then the job is over, watch the spectacular explosion. Unable to spot the Pinwheel? No problem. Find out the Big Dipper's handle and focus to the last two stars, where to the north of these stars you can find the Pinwheel galaxy. Don't miss the spectacular show by VJ SN 2011fe. Happy Watching Amateurs :-)

Ref: Los Angeles Times
September 10,2011.

Pranu :-)

Universe @ Partiality ?

In the present scenario, we all believe that the universe is expanding and accelerating it's expansion equally in all the directions as seen from the Earth. But this has been almost proved wrong.Rong-Gen Cai and Zhong-Liang Tuo at the Key Laboratory of Frontiers in Theoretical Physics at the Chinese Academy of Sciences in Beijing have conducted experiments and gave conclusions after observing the movement of 557 supernovae visible through out the universe. They concluded that the movement is accelerating at greater speeds in the constellation of Vulpecula in the Northern hemisphere. This is not the end but at the same time, this is the most important thing one could ever think of. Lets wait and see for more experiments to reveal that the universe is partial about it's expansion and selects only a few directions for it's expansion. May be this is even gonna disprove the Cosmological principle.

Ref: Technology review
 September 7, 2011.

Pranu :)

hIGGS bOSON by this Christmas??

Researchers at LHC say on 1 September, 2011 that they are gonna find out if there are Higgs Bosons by this Christmas. LHC spokesman, Professor Guido Tonelli, has told BBC News that the machines are successfully running and thus the search would be completed before the expected date. Professor Tonelli says, "We could discover the Standard Model version of the Higgs Boson or exclude it earlier than expected. Could we discover it by Christmas? In principle, yes,"

Higgs particle, been announced about its presence in 1964 is not yet seen practically but on which most of the theory depends. Two proton beams are collided in this LHC and detectors are placed at the collision point to record these collisions. Generally the number of collisions are calculated in units called "inverse femtobarns". One inverse femtobarn is equal to around 70 million million (70 x 10¹²) collisions. Researchers at LHC are aiming to complete 5 inverse femtobarns out of which 2.5 have been completed as of date and expecting to complete the remaining by this Christmas. But again Richard Hawkings, who speaks for the LHC's Atlas experiment doubts that 5 inverse femtobarns may not be sufficient to complete the research.

Whatever, either of the two: discovery or elimination of these higgs boson would be completed by this Christmas. Lets wait to see if the result is yes or no but as every physicist, even I wish the answer would be yes as higgs boson particle has been the stand for many theories since ages !! I will keep updating the blog daily with the progress of this experiment and keep checking.

September, 03, 2011.
Ref: BBC news

Pranu :)

Two Blackholes in one NASA shot

NASA's Chandra X-ray Observatory has discovered a pair of super massive black holes on September 1,2011.It's found that this pair is about 160 million light years from the Earth in situated in a spiral galaxy NGC 3393, which looks very similar to the Milky way. Pepi Fabbiano of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge says, "If this galaxy weren’t so close, we’d have no chance of separating the two black holes the way we have, since this galaxy was right under our noses by cosmic standards, it makes us wonder how many of these black hole pairs we’ve been missing,” . Seems this pair of galaxies could be seen only with the help of X-rays as the galaxies are totally obstructed by dust.

Picture taken 2 days back by Chandra's X-Ray Observatory

Co-author Guido Risaliti of CfA and the National Institute for Astrophysics in Florence, Italy says, “Collisions and mergers are one of the most important ways for galaxies and black holes to grow, Finding a black hole pair in a spiral galaxy is an important clue in our quest to learn how this happens".

Sept 2, 2011.

Pranu :)

Impossible star in the Forbidden Zone

ESO’s Very Large Telescope (VLT)observed a star sparkling in the forbidden zone, amazing the Astronomers on September 1, 2011. Astronomers named it as SDSS J102915+172927. Its estimated to be about 13 billion years old.

  

Figure is a pie-diagram of the constituents of the star SDSS J102915+172927 and lack of the heavier elements as well as it's percentage of the total composition

 

Stars are dropped into 3 groups out of which one is Population 1. These stars contain metals which account for about 2 to 3 % of the star's composition. The second population 2 stars have 0.01 to 0.1 % of metals whereas the third type dubbed population 3 stars don't contain metals at all. One more thing about these stars is that due to their heavy mass, its predicted that they would have died at the beginning of the universe, itself. Population 3 stars can only be cooled by the hydrogen. Its also proved in recent studies that the death of these stars would have enriched the surrounding galactic medium with heavy   amounts of carbon and oxygen.

But this star, now discovered is found to be devoid of any heavier metals.So according to the above discussed facts, this star should be one of the population 3 stars. But the odd thing about this star is that it doesn't even contain any traces of the carbon and oxygen and this amazes the astronomers to a confusing extent. Because this means it didn't have anything reasonable to cool the star, as far as we know.

Caffau, lead author of the paper tells Astronomy Now Magazine tried to explain it this way: “One mechanism is cooling by dust, that leads to a much lower critical metallicity than cooling by fine structure lines of CII and OI,” and “Another mechanism is fragmentation. If a massive cloud collapsing to form a high mass stars breaks up a few small mass fragments, these can form low mass stars.” One more thing which made this star stand in the forbidden zone is that this star even lacks the lithium, which is supposed to be contained in along with the many other stars in that galaxy. So the methodology involved in the formation of this star is still a mystery and as with every strange thing happening in the universe, I hope this is gonna reveal some mysteries about the origin of the universe, as an astro-lover.

Ref: Astronomy Now magazine.
Sept 2nd, 2011.

Pranu :)