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  • April 12, 2012
  • 10:49 PM
  • 2,630 views

Disassociate Galaxy Clusters

by The Astronomist in The Astronomist.

A dissociative galaxy cluster is a cluster of galaxies that just can't keep it together any longer. This may sound like an unnecessary anthropomorphication of galaxies, but it is actually a description of galaxy clusters which have collided and experienced stratification of their constituent parts. In the standard and successful model of cosmology the largest scale structures in the universe, like super clusters of thousands of galaxies, form via the merger of filamentary structures compose........ Read more »

Dawson, W., Wittman, D., Jee, M., Gee, P., Hughes, J., Tyson, J., Schmidt, S., Thorman, P., Bradač, M., Miyazaki, S.... (2012) DISCOVERY OF A DISSOCIATIVE GALAXY CLUSTER MERGER WITH LARGE PHYSICAL SEPARATION. The Astrophysical Journal, 747(2). DOI: 10.1088/2041-8205/747/2/L42  

Jee, M., Mahdavi, A., Hoekstra, H., Babul, A., Dalcanton, J., Carroll, P., & Capak, P. (2012) A STUDY OF THE DARK CORE IN A520 WITH THE : THE MYSTERY DEEPENS . The Astrophysical Journal, 747(2), 96. DOI: 10.1088/0004-637X/747/2/96  

Markevitch, M., Gonzalez, A., Clowe, D., Vikhlinin, A., Forman, W., Jones, C., Murray, S., & Tucker, W. (2004) Direct Constraints on the Dark Matter Self‐Interaction Cross Section from the Merging Galaxy Cluster 1E 0657−56. The Astrophysical Journal, 606(2), 819-824. DOI: 10.1086/383178  

  • December 12, 2011
  • 04:10 PM
  • 6,176 views

The First Quantum Computer

by The Astronomist in The Astronomist.

In a nondescript office park outside Vancouver with views of snow capped mountains in the distance is a mirrored business park where very special work is being done. The company is D-Wave, the quantum computing company. D-Wave's mission is to build a computer which will solve humanity's grandest challenges.D-Wave aims to develop the first quantum computer in the world, perhaps they already have. The advent of quantum computers would be a sea change in the world that would allow for breaking of c........ Read more »

Harris, R., Johansson, J., Berkley, A., Johnson, M., Lanting, T., Han, S., Bunyk, P., Ladizinsky, E., Oh, T., Perminov, I.... (2010) Experimental demonstration of a robust and scalable flux qubit. Physical Review B, 81(13). DOI: 10.1103/PhysRevB.81.134510  

Harris, R., Johnson, M., Han, S., Berkley, A., Johansson, J., Bunyk, P., Ladizinsky, E., Govorkov, S., Thom, M., Uchaikin, S.... (2008) Probing Noise in Flux Qubits via Macroscopic Resonant Tunneling. Physical Review Letters, 101(11). DOI: 10.1103/PhysRevLett.101.117003  

  • March 26, 2011
  • 12:01 AM
  • 2,343 views

Naming the Unknown #1

by The Astronomist in The Astronomist.

Naming the Unknown is a new series where I highlight interesting papers in astrophysics. Research papers which I find compelling or of general interest will be spotlighted. The title 'Naming the Unknown' comes from accusation that cosmologists have simply begun to come up with names for those things which are not understood; yet, I do not think that anyone would claim that science is at times anything other than coming up with names for the unknown. Scientists define the unknown in terms of the ........ Read more »

  • December 20, 2010
  • 04:26 PM
  • 2,222 views

Two stars merge on camera

by Professor Astronomy in Professor Astronomy

No, it's not the latest celebrity scandal.  But a group of astronomers think they may have seen two stars in space spiral together, combine in a rare type of stellar eruption, and combine to make a single star.

Our story begins with a type of event called a nova (plural: novae).   Novae are typically thought to be nuclear explosions on the surface of white dwarf stars.  White dwarfs are the remains of stars that have used all of their nuclear fuel.  If a white dwarf can........ Read more »

R. Tylenda, M. Hajduk, T. Kamiński, A. Udalski, I. Soszyński, M. K. Szymański, M. Kubiak, G. Pietrzyński, R. Poleski, Ł. Wyrzykowski.... (2010) V1309 Scorpii: merger of a contact binary. Astronomy . arXiv: 1012.0163v1

  • December 16, 2010
  • 09:56 PM
  • 3,161 views

Supermassive Black Holes

by The Astronomist in The Astronomist.

A black hole is a massive object with such powerful gravity that not even light may escape from it. Black holes only have three unique properties which are mass, charge, and spin. At one time black holes were a speculative phenomena, but astronomers now understand that black holes are a relatively common and important occurrence in our Universe, unfortunately the public and science fiction still seems to be in dark. There are a lot of misconceptions about black holes:If the Sun was replaced........ Read more »

Gebhardt, K., Bender, R., Bower, G., Dressler, A., Faber, S., Filippenko, A., Green, R., Grillmair, C., Ho, L., Kormendy, J.... (2000) A Relationship between Nuclear Black Hole Mass and Galaxy Velocity Dispersion. The Astrophysical Journal, 539(1). DOI: 10.1086/312840  

Genzel, R., Schödel, R., Ott, T., Eckart, A., Alexander, T., Lacombe, F., Rouan, D., & Aschenbach, B. (2003) Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre. Nature, 425(6961), 934-937. DOI: 10.1038/nature02065  

Ghez, A., Salim, S., Weinberg, N., Lu, J., Do, T., Dunn, J., Matthews, K., Morris, M., Yelda, S., Becklin, E.... (2008) Measuring Distance and Properties of the Milky Way’s Central Supermassive Black Hole with Stellar Orbits. The Astrophysical Journal, 689(2), 1044-1062. DOI: 10.1086/592738  

  • October 30, 2010
  • 11:05 PM
  • 3,126 views

Very precise pulsar measurements

by The Astronomist in The Astronomist.

A neutron star is made of neutrons, right? Astrophysicists ponder this question and forge theory after theory, but the only thing they conclude with certainty is that a neutron star by any other name would still be made of the densest form of matter know to exist in our Universe. Under certain conditions a star which has exhausted all of its fuel and is sufficiently massive will not be able to support its own weight with pressure support (as in a regular star) or with electron degeneracy support........ Read more »

Demorest PB, Pennucci T, Ransom SM, Roberts MS, & Hessels JW. (2010) A two-solar-mass neutron star measured using Shapiro delay. Nature, 467(7319), 1081-3. PMID: 20981094  

D. J. Champion, G. B. Hobbs, R. N. Manchester, R. T. Edwards, D. C. Backer, M. Bailes, N. D. R. Bhat, S. Burke-Spolaor, W. Coles, P. B. Demorest.... (2010) Measuring the mass of solar system planets using pulsar timing. ApJ. arXiv: 1008.3607v1

  • October 25, 2010
  • 09:04 AM
  • 1,474 views

Meteorite tea, and the failures of genius

by Lab Lemming in Lounge of the Lab Lemming

In the early 1970’s, Io, the innermost large moon of Jupiter, was somewhat of an enigma. Unlike Europa and Ganymede, it did not exhibit water ice adsorption bands it its IR spectra. Its density suggested that it was a rock and metal planet, but the surface reflectance was unlike anything known to science. This problem was addressed brilliantly in a Science paper by Fanale, Johnson, and Matson,... Read more »

Fanale, F., Johnson, T., & Matson, D. (1974) Io: A Surface Evaporite Deposit?. Science, 186(4167), 922-925. DOI: 10.1126/science.186.4167.922  

  • October 16, 2010
  • 10:37 PM
  • 2,897 views

The Goldilocks Planet

by The Astronomist in The Astronomist.

Once upon a time there was a planet named Earth. It orbited exactly one astronomical unity away from a G2V type star. Billions of years went by and Earth found that it lived right in the habitable zone where liquid water was maintained on it surface and life spontaneously arose. Pretty soon life on Earth became restless, questioned its own existence, and looked for life on Gliese 581. Earthlings found many planets and exclaimed, 'Gliese 581 b is too hot, Gilese 581 c is slightly too hot, Glies........ Read more »

Steven S. Vogt, R. Paul Butler, Eugenio J. Rivera, Nader Haghighipour, Gregory W. Henry, . (2010) The Lick-Carnegie Exoplanet Survey: A 3.1 M_Earth Planet in the Habitable Zone of the Nearby M3V Star Gliese 581. ApJ accepted. info:/arXiv: 1009.5733v1

  • October 15, 2010
  • 05:12 PM
  • 2,055 views

Gliese 581 g: The Goldilocks that isn’t?

by sarah in One Small Step

The discovery of planet Gliese 581 g, an exoplanet just 3 times the mass of our Earth  and located in its host star’s Habitable Zone, was one of the biggest science headlines of the year. The news broke, typically, somewhere between my observing proposal deadline and box number 15: “all the crap that didn’t fit [...]... Read more »

Steven S. Vogt, R. Paul Butler, Eugenio J. Rivera, Nader Haghighipour, Gregory W. Henry, & Michael H. Williamson. (2010) The Lick-Carnegie Exoplanet Survey: A 3.1 M_Earth Planet in the Habitable Zone of the Nearby M3V Star Gliese 581. ApJ accepted. arXiv: 1009.5733v1

  • September 13, 2010
  • 07:38 PM
  • 3,419 views

Magnetic Fields in Cosmology

by The Astronomist in The Astronomist.

The existence of magnetic fields on cosmologically large scales is an unsolved problem in astrophysics. Theory favors a universe that did not begin with any magnetic fields present and classical magnetohydrodynamics restricts the spontaneous emergence of a magnetic state under the influence of ideal forces. In a paper entitled Twisting Space-Time: Relativistic Origin of Seed Magnetic Field and Vorticity appearing Physical Review letters Swadesh Mahajan and Zensho Yoshida propose a universal magn........ Read more »

Beck, R., Brandenburg, A., Moss, D., Shukurov, A., & Sokoloff, D. (1996) GALACTIC MAGNETISM: Recent Developments and Perspectives. Annual Review of Astronomy and Astrophysics, 34(1), 155-206. DOI: 10.1146/annurev.astro.34.1.155  

  • September 10, 2010
  • 12:07 AM
  • 1,915 views

Paper: Detection of a "Superbolide" on Jupiter

by Jason Perry in The Gish Bar Times

A paper was published today online in the Astrophysical Journal Letters on the June 3 fireball on Jupiter.  The impact produced a bright flash that was seen all the way from Earth by two amateur astronomers: Christopher Go in Cebu, Philippines and Anthony Wesley in Murrumbateman, Australia.  We discussed the impact at the time as not one but two detections of this impact were confirmed.  This new paper is titled, "First Earth-based Detection of a Superbolide on Jupiter," by Ricar........ Read more »

R. Hueso, A. Wesley, C. Go, S. Perez-Hoyos, M. H. Wong, L. N. Fletcher, A. Sanchez-Lavega, M. B. E. Boslough, I. de Pater, G. S. Orton.... (2010) First Earth-based Detection of a Superbolide on Jupiter. The Astrophysical Journal Letters, 721(2). info:/10.1088/2041-8205/721/2/L129

  • September 7, 2010
  • 09:26 AM
  • 2,309 views

Exoplanets at a discount

by sarah in One Small Step

Astronomers have many ways of spotting exoplanets round far away stars – but getting a direct look at them, especially with ground-based telescopes, remains a difficult job. With a planet emitting very little light of its own, and appearing to us essentially on top of the host star, its radiation is completely drowned in the [...]... Read more »

Sascha P. Quanz, Michael R. Meyer, Matthew Kenworthy, Julien H. V. Girard, Markus Kasper, Anne-Marie Lagrange, Daniel Apai, Anthony Boccaletti, Mickael Bonnefoy, Gael Chauvin.... (2010) First Results From VLT NACO Apodizing Phase Plate: 4-micron Images of the Exoplanet beta Pictoris b. ApJ Letters. arXiv: 1009.0538v1

A.-M. Lagrange, M. Bonnefoy, G. Chauvin, D. Apai, D. Ehrenreich, A. Boccaletti, D. Gratadour, D. Rouan, D. Mouillet, S. Lacour.... (2010) A giant planet imaged in the disk of the young star Beta Pictoris. Science, 329(5987), 57-59. arXiv: 1006.3314v1

Matthew A. Kenworthy, Sascha P. Quanz, Michael R. Meyer, Markus E. Kasper, Rainer Lenzen, Johanan L. Codona, Julien H. V. Girard, & Philip M. Hinz. (2010) An apodizing phase plate coronagraph for VLT/NACO. Proc. SPIE. arXiv: 1007.3448v1

  • August 29, 2010
  • 11:36 AM
  • 2,666 views

the birth of a supermassive monster, revisited

by Greg Fish in weird things

We know that black holes can grow to become absolutely enormous in size, tipping the scales at billions and billions of times the mass of our sun. The numbers involved make the gravitational monsters in question very hard to visualize, and pose a big mystery. Did they form from the remnants of the first stars [...]... Read more »

  • August 24, 2010
  • 08:00 PM
  • 1,512 views

This Week in the Universe: August 17th – August 23rd

by S.C. Kavassalis in The Language of Bad Physics

What have people been talking about this week in high energy physics, astrophysics, gravitation, general relativity and quantum gravity?... Read more »

Lo Curto, G., Mayor, M., Benz, W., Bouchy, F., Lovis, C., Moutou, C., Naef, D., Pepe, F., Queloz, D., Santos, N.... (2010) The HARPS search for southern extra-solar planets XXVII. Astronomy and Astrophysics. info:other/10.1051/0004-6361/200913523

D. J. Champion, G. B. Hobbs, R. N. Manchester, R. T. Edwards, D. C. Backer, M. Bailes, N. D. R. Bhat, S. Burke-Spolaor, W. Coles, P. B. Demorest.... (2010) Measuring the mass of solar system planets using pulsar timing. Astrophysical Journal. arXiv: 1008.3607v1

Berné O, Marcelino N, & Cernicharo J. (2010) Waves on the surface of the Orion molecular cloud. Nature, 466(7309), 947-9. PMID: 20725034  

Ephraim Fischbach,, Peter A. Sturrock,, Jere H. Jenkins,, Daniel Javorsek II,, John B. Buncher,, & John T. Gruenwald. (2010) Evidence for Solar Influences on Nuclear Decay Rates . Fifth Meeting on CPT and Lorentz Symmetry. info:/1007.3318

P. E. Koehler, F. Bečvář, M. Krtička, J. A. Harvey, & K. H. Guber. (2010) Anomalous fluctuations of s-wave reduced neutron widths of $^{192,194}$Pt resonances. Phys. Rev. Lett. , 105(7). arXiv: 1007.3675v1

Palenzuela, C., Lehner, L., & Liebling, S. (2010) Dual Jets from Binary Black Holes. Science, 329(5994), 927-930. DOI: 10.1126/science.1191766  

  • August 3, 2010
  • 06:28 PM
  • 2,123 views

New limit on neutrino mass… from cosmology, not particle physics

by Kelly Oakes in Basic Space

Physicists at University College London have found a new upper limit on the mass of a neutrino – one of the tightest constraints yet from either particle physics or cosmology. Neutrinos are elementary particles that travel close to the speed of light, but are very difficult to detect because they are not electrically charged. In [...]... Read more »

  • August 2, 2010
  • 07:02 AM
  • 2,297 views

Massive star formation not so different after all?

by sarah in One Small Step

In my previous post on the Zooniverse Project IX I’m involved in, I talked about the importance of star formation in the Universe and some of the difficulties we face in studying it. Some big unanswered question particularly remain in our understanding of how massive stars form. Fittingly, the latest edition of Nature has a [...]... Read more »

Kraus S, Hofmann KH, Menten KM, Schertl D, Weigelt G, Wyrowski F, Meilland A, Perraut K, Petrov R, Robbe-Dubois S.... (2010) A hot compact dust disk around a massive young stellar object. Nature, 466(7304), 339-42. PMID: 20631793  

  • July 30, 2010
  • 08:42 AM
  • 1,189 views

Not the bang they were looking for

by Niall in we are all in the gutter

A satellite detects a bright burst of gamma-rays. Within minutes telescopes swing in to action expecting to see a massive star being torn apart by a cataclysmic explosion in a far-flung corner of the universe. But that wasn't what they found........... Read more »

Rachel A. Osten, Olivier Godet, Stephen Drake, Jack Tueller, Jay Cummings, Hans Krimm, John Pye, Valentin Pal'shin, Sergei Golenetskii, Fabio Reale.... (2010) The Mouse that Roared: A Superflare from the dMe Flare Star EV Lac detected by Swift and Konus-Wind. Accepted for publication in the Astrophysical Journal. arXiv: 1007.5300v1

  • July 29, 2010
  • 04:51 PM
  • 3,276 views

Hubble Bubble

by The Astronomist in The Astronomist.

The Copernican principle holds that humans are not privileged observers of the Universe. Copernicus stated that the Earth is not at the center of the solar system or at any particularly special position in the heavens. Modern cosmology has extended this idea to reason that the earth does not occupy any unique position in the Universe. Modern philosophy of science pushes the principle even further to conclude that every observer (even if they be they little green men) should reason as if they wer........ Read more »

Adam Moss, James P. Zibin, & Douglas Scott. (2010) Precision Cosmology Defeats Void Models for Acceleration. arXiv preprint. arXiv: 1007.3725v1

  • July 26, 2010
  • 10:23 PM
  • 2,077 views

This Week in the Universe: July 20th – July 26th

by S.C. Kavassalis in The Language of Bad Physics

What have people been talking about this week in high energy physics, astrophysics, gravitation, general relativity and quantum gravity?... Read more »

Paul A Crowther, Olivier Schnurr, Raphael Hirschi, Norhasliza Yusof, Richard J Parker, Simon P Goodwin, & Hasan Abu Kassim. (2010) The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit. Monthly Notices of the Royal Astronomical Society. arXiv: 1007.3284v1

Seth Lloyd, Lorenzo Maccone, Raul Garcia-Patron, Vittorio Giovannetti, & Yutaka Shikano. (2010) The quantum mechanics of time travel through post-selected teleportation. arXiv. arXiv: 1007.2615v2

  • July 22, 2010
  • 04:16 PM
  • 2,290 views

Mapping the cosmos: Can a new technique help us learn more about dark energy?

by Kelly Oakes in Basic Space

In a paper published in Nature today, physicists detail a new method of looking at faraway galaxies that may help shed light on dark energy. In order to learn more about dark energy – the mysterious force that is believed to be responsible for the ever increasing rate of expansion of the Universe – astronomers [...]... Read more »

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