Pr-28-01.html PR Photo 35b/01 VLT spectrum of a MACHO. The Riddle of dark matter. The natureof dark matter is one of the fundamental puzzles in astrophysics today. http://www.eso.org/outreach/press-rel/pr-2001/pr-28-01.html
Extractions: ESO OUTREACH HOME INDEX HELP ... PRESS RELEASES Information from the European Southern Observatory Embargoed until Wednesday, December 5, 2001, 20:00 hrs CET (19 hrs UT) Summary An international team of astronomers has observed a Dark Matter object directly for the first time Images and spectra of a MACHO microlens - a nearby dwarf star that gravitationally focuses light from a star in another galaxy - were taken by the NASA/ESA Hubble Space Telescope (HST) and the European Southern Observatory's Very Large Telescope (VLT) The result is a strong confirmation of the theory that a large fraction of Dark Matter exists as small, faint stars in galaxies such as our Milky Way PR Photo 35a/01 : HST image of a MACHO. PR Photo 35b/01 : VLT spectrum of a MACHO. The nature of Dark Matter is one of the fundamental puzzles in astrophysics today. Observations of clusters of galaxies and the large scale structure of individual galaxies tell us that no more than a quarter of the total amount of matter in the Universe consists of normal atoms and molecules that make up the familiar world around us. Of this normal matter, no more than a quarter emits the radiation we see from stars and hot gas. So, a large fraction of the matter in our Universe is dark and of unknown composition For the past ten years, active search projects have been underway for possible candidate objects for Dark Matter. One of many possibilities is that the Dark Matter consists of weakly interacting, massive sub-atomic sized particles known as
October Astrophysics Conference In Maryland Please contact the hotels directly for reservations, and indicate that you arean attendee of the dark matter astrophysics conference at the University http://www.astro.umd.edu/october/bull2.1994.html
Extractions: The Conference will be held at the University Conference Center (formerly the Center of Adult Education) at the University of Maryland, College Park, MD. It will run for three days, Monday through Wednesday, October 10-12, 1994. This will be the fifth in a series of topical conferences that are arranged each autumn by scientists at the Goddard Space Flight Center and the University of Maryland. Each of the conferences is devoted to a single topic in astrophysics research, and is organized to elicit the free discussion of ideas. We anticipate that this year's conference, entitled Dark Matter, will be as successful as were the four previous conferences: After the First Three Minutes, Testing the AGN Paradigm, Back to the Galaxy, and The Evolution of X-Ray Binaries. The conference will be devoted to the discussion of new data and ideas associated with astrophysical evidence for Dark Matter on all scales. It will be organized into sessions that are 2 to 2-1/2 hours in duration. A typical session will include two or three formal invited talks (each about 30-minutes) and might also include a few 5 to 10-minute oral contributions selected by the session chair from the submitted poster abstracts. The chair will encourage free discussion of the session topic (if the privilege is not abused, any attendee might have one minute to present one viewgraph as part of the discussions). Short oral contributions are selected from abstracts that were received prior to the August 1 deadline indicated in Bulletin #1. Authors of papers selected for short presentations (AND ONLY THOSE AUTHORS) will be informed before October 1 if you are not contacted please do NOT call the conference organizers or the session chairs. Programme
Galaxy - Dark Matter Connection the MaxPlanck Institute for Astrophysics have developed a new technique to linkthe observed distribution of galaxies to the distribution of dark matter halos http://www.mpa-garching.mpg.de/HIGHLIGHT/2002/highlight0206_e.html
Extractions: Scientists at the Max-Planck Institute for Astrophysics have developed a new technique to link the observed distribution of galaxies to the distribution of dark matter halos. In the current cosmological framework the vast majority of matter is made up of some hitherto undetected particles. This cold dark matter matter, as it is generally called, is assumed to form dark matter halos inside of which galaxies form. Over the past decades scientist have developed a detailed understanding of the growth of such dark matter halos. In particular, accurate descriptions are nowadays available for the mass function of dark matter halos, which describes how many halos there are of given mass, as well as of their clustering properties (see Figure [1]). In recent years, large redshift surveys of galaxies have become available from which scientist have obtained similar statistical properties for the distributions of galaxies (see Figure [2]). Scientists at the Max-Planck Institute for Astrophysics have now developed a new technique to link the observed distribution of galaxies to the distribution of dark matter halos. Figure 1: The distribution of dark matter obtained from a large numerical simulation. Note how the dark matter is clustered into dark matter halos, which are connected by a large filamentary network. It is form simulations like these that astrophysicists have obtained a detailed understanding of the abundance and clustering of dark matter halos. This particular simulation is performed by the Virgo consortium, including scientists from the Max-Planck Institute for Astrophysics (see Jenkins et al. 1998, Astophysical Journal, 499, 20-40)
No Dark Matter Found In The Milky Way Galaxy One recent experimental report by Crézé et al. in Astronomy and Astrophysics hasconcluded that there is no dark matter in the disk of the Milky Way Galaxy. http://www.answersingenesis.org/home/area/magazines/tj/v13n1_milky-way.asp
Extractions: UPHOLDING THE AUTHORITY OF THE BIBLE FROM THE VERY FIRST VERSE SEARCH Contact Us Home Store Events ... Contact us Refuting Compromise A biblical and scientific refutation of Progressive Creationism (billions of years). Order your copy today. Bookstore and resource center Creation Magazine Subscribe Renew Search Archives: Upcoming Events Handsworth, Birmingham, United Kingdom Columbus, Ohio, United States Kununurra, WA, Australia Whitby, Yorkshire, United Kingdom ... Printer-friendly version by Michael Oard and Jonathan Sarfati First published in: Creation Ex Nihilo Technical Journal Many astronomers, because of their presuppositions, believe that 90 % of the mass of the universe is invisible matter, called dark matter. The dark matter is believed to exist in several forms: hot dark matter, 20 % of the total, and cold dark matter, 70 % of total. The dark matter could include neutrinos, burnt-out stars, smaller chunks of ordinary matter, or clouds of mysterious, exotic particles. Nature says Dark matter is also required to hold the galaxies together during all the supposed time the universe has existed: So naturally evolutionary astronomers have been conducting experiments to observe the gravitational effects of dark matter.
Dark Matter 32 No. 6. dark matter. Yorck Ramachers Oxford University, NAPL, Keble Road, OX13RH, UK. dark matter is among the hottest topics of research in astrophysics. http://www.europhysicsnews.com/full/12/article15/article15.html
Extractions: Oxford University, NAPL, Keble Road, OX1 3RH, UK D ark matter is among the hottest topics of research in astrophysics. Although the phenomenon has been noticed the first time almost seventy years ago by F. Zwicky, in recent times dark matter research entered a new era. Its existence is practically accepted due to independent and converging observations in astrophysics (see also the articles in this special issue by J.M. Lamarre and J.L. Puget and by P.D. Sackett). However, the actual composition of dark matter is yet to be determined. Dark matter as a puzzle inspires astrophysicists and particle physicists, amalgamating these research areas into the rather young discipline of astroparticle physics. To summarize roughly the present status, the overwhelming majority of mass in the universe neither emits nor absorbs light and nobody knows what it is made of. The exercise is clear: to reveal the nature of dark matter and its role in the universe. Mass and energy budget of the Universe
Extractions: We present new HI observations of the high-velocity cloud (HVC) that we resolved near the Local Group dwarf galaxy LGS 3. The cloud is rotating, with an implied mass that makes it dark matter-dominated no matter what its distance from the Milky Way is. Our new, high-sensitivity Arecibo observations demonstrate that the faint HI features that we previously described as tidal tails are indeed real and do connect to the main body of the HVC. Thus, these observations are consistent with our original hypothesis of a tidal interaction between the HVC and LGS 3. We suggest that the HVC may be one of the missing dark matter satellites in the Local Group that are seen in Cold Dark Matter numerical simulations but have not yet been identified observationally. References and citations for this submission:
[astro-ph/0404490] Integral And Light Dark Matter no ESA SP552 The nature of dark matter remains one of the outstandingquestions of modern astrophysics. The success of the Cold http://arxiv.org/abs/astro-ph/0404490
Astro News - Center For Astrophysics The dark matter from our Universe was finally observed! Astronomers have knownfor a long time that most of the mass of the Universe is dark matter. http://www.astro.up.pt/nd/astro_news/2001/1211uk.html
Extractions: The dark matter from our Universe was finally observed! Using HST and VLT, the astronomers were able to make the first direct observation of a dark matter object. Looking at a distant blue star in the Large Magellanic Cloud and using a gravitational micro-lens, it was possible to observe the object responsible for this effect: a dwarf star 600 light years from our Sun. Astronomers have known for a long time that most of the mass of the Universe is Dark Matter. According to the latest models, the Dark Matter can be found in one (or both) of these forms: WIMP's and MACHO's. WIMP's (Weakly Interactive Massive Particle) are highly massive sub-atomic particles, very different from the matter we know. One of their main features is a poor interaction with normal matter. Up: HST image where we can see the blue star and by its side the detected dwarf star (red object poited by the arrow). MACHO's (MAssive Compact Halo Objects) are small but very massive astronomical objects. They are made of the same atoms and molecules that make and surround us. MACHO's can be dwarf stars, dying stars (such as white dwarfs, neutrons stars, pulsars and black holes) and planets. Although they are completely different, both of the Dark Matter forms have one thing in common: they are extremely difficult to detect directly because they emit little or no light at all. The only evidence that we had of the existence of Dark Matter was it's gravitational influence on the dynamics of galaxies and galaxy clusters. Looking at our universe one can conclude that the matter we see is only a small portion of the needed matter to form the large scale structures that we can observe. More than three-quarters of all matter in the Universe should be Dark Matter.
Hot On The Gas Trail Of Ordinary Dark Matter Service Professor in Astronomy Astrophysics at the University of Chicago. FUSEhas great potential to shed light on this important dark matter problem. http://www.spacedaily.com/news/darkmatter-00d.html
Extractions: Chicago - August 3, 2000 - Astronomers analyzing data from the Far Ultraviolet Spectrographic Explorer satellite have found the interstellar signposts that may lead them to the direct detection of ordinary dark matter in the universe, one of the major quests of modern astronomy. They also have eliminated the possibility that one leading suspect molecular hydrogen accounts for any significant portion of dark matter, the composition of which remains a big mystery. Various lines of evidence have led astronomers to believe that 90 ercent of ordinary matter in the universe, matter made of neutrons and protons, is dark, invisible to them. Now it seems likely, on theoretical grounds, that a significant portion of dark matter may consist of million-degree gas. "We have the equipment to test this theory, one way or the other," York said. "The hot gas is the last great hope. If that doesn't turn out right, then we'll have to start over again." These results, which are based on three months of observations targeting 20 objects outside the galaxy, appear in a special issue of the Astrophysical Journal Letters. The FUSE science team, led by Johns Hopkins University's Warren Moos, includes York at Chicago and other astronomers at Johns Hopkins; University of California, Berkeley; University of Colorado; University of Wisconsin, Madison; Harvard University; NASA's Goddard Space Flight Center, Canada, France, and elsewhere.
Searching For Dark Matter Using Gravitational Lensing range of expertise cosmology, astrophysics, statistics, data analysis and instrumenttechnology needed for the research. The nature of dark matter is one http://www.spacedaily.com/news/darkmatter-00c1.html
Extractions: Numerical simulation showing the distribution of dark matter in a large volume of the universe. The box shown spans a distance of about 1 billion light-years. The structures are displayed so that the brighter regions have a higher density (that is, more dark matter) than the darker regions. The dark matter is concentrated into a web-like distribution of filaments that intersect at dense nodes where great clusters of galaxies are expected to form and become visible. At the rear of the cube (to the left), three blue disks represent three distant galaxies. The yellow lines that cross the box represent light rays from those galaxies propagating through the universe. In the absence of intervening matter, the light would travel on straight lines but in the presence of matter, the paths of the rays are evidently deflected by the gravitational effects of the clumpy matter (the breaks in the yellow lines illustrate the light passing behind a clump of dark matter). The light from a distant galaxy rarely encounters a clump of mass to strongly bend the light and cause an easily seen distortion. Instead the individual light rays suffer a series of small deflections such that an observer located at the front of the box (to the right), sees that the images of all the galaxies in some small patch of the sky, near to one of our test galaxies say, are all very slightly elongated in a common direction determined by the distribution of dark matter along that particular line of sight. This gravitational distortion is expected to be very small and requires a careful statistical treatment on many patches over the sky but has now been measured by the French team. Numerical simulation by S. Colombi
Discovery Of H2 In Space Explains Dark Matter And Redshift The halo culture that has grown up around the dark matter problem might In most papersin astrophysics, the word hydrogen is mentioned without distinguishing http://www.newtonphysics.on.ca/hydrogen/
Extractions: Explains Dark Matter and Redshift by Paul Marmet In papers published about a decade ago, the author and colleagues predicted the widespread presence of hydrogen in the molecular (H ) form in space ( Marmet and Reber 1989 Marmet 1990a,b ). Although hydrogen in the atomic form is easily detected through radioastronomy, the molecular form is difficult to detect. We showed that the presence of this missing mass would explain the anomalous rotational motion observed in galaxies, which is otherwise explained by exotic hypotheses, such as swarms of invisible brown or white dwarfs, or weird atomic particles called WIMPs or axions, and "quark nuggets." We also showed that the presence of large amounts of the hard-to-detect molecular hydrogen in interstellar space could provide an alternative explanation to the Big Bang theory, by explaining the observed redshift as a result of the delayed propagation of light through space, caused by the collision of photons with interstellar matter. The more commonly held view explains the observed shift in frequency of the spectral lines detected from distant galaxies as arising from a Doppler shift (a shift in the frequency of a wave caused by the relative motion of the emitting object and the observer). The downshift in the frequency, toward the red end of the spectrum, is taken to mean that distant galaxies are receding from us, thus implying an expanding universe.
Dark Matter Determining whether dark matter exists, and in what quantity, aresome of the most challenging problems in modern astrophysics. http://www.claudette.shalfleet.net/astrophysics/darkmatter.htm
Extractions: Dark Matter is classified as nonluminous material that cannot be directly detected by observing any form of electromagnetic radiation, but whose existence, distributed throughout the universe, is suggested by certain theoretical considerations. Determining whether dark matter exists, and in what quantity, are some of the most challenging problems in modern astrophysics. Three principal theoretical considerations suggest that dark matter exists. The first is based on the rotation rate of galaxies. Galaxies near the Milky Way appear to be rotating faster than would be expected from the amount of visible matter that appears to be in these galaxies. Many astronomers believe there is enough evidence to conclude that up to 90 per cent of the matter in a typical galaxy is invisible. The third theoretical consideration that suggests that dark matter exists is based on the inflationary big bang model. Of the three types of consideration suggesting the existence of dark matter, this is the most controversial. According to the idea of cosmic inflation, the universe went through a period of extremely rapid expansion when very young. However, if the inflationary big bang model is correct, then the cosmological constant describing the expansion of the universe is close to 1. In order for this constant to be near 1, the total mass of the universe must be more than 100 times the amount of visible mass that appears to exist.
CosPA2003 Symposium Coffee Break. 1045-1230 dark Energy and dark matter (III). -Lunch-. Lunch-.1300-1445 Neutrino Astrophysics and Cosmology (I). -Coffee Break-. http://www.cospa.ntu.edu.tw/cospa2003/
Extractions: Last updated: Sat, 12/20/2003 5:25 Keynote Speech CMB Cosmology Dark Energy and Dark Matter New Physics ... List of Participants contents Generalities Taida CosPA Center will organize the 2003 International Symposium on Cosmology and Particle Astrophysics, CosPA 2003, the second meeting in the series, which was rescheduled from early May this year (due to the SARS epidemic in part of Asia) to November 13-15. It is hoped that the symposium will serve as the forum for researchers to exchange ideas in the forefronts of cosmology and particle astrophysics. The proceedings will be published. Our primary goal is to bring together scientists to engage serious discussions on the following topics, with
Astrophysics Group - West Astrophysics Group West, AstrophysicsGroupWest@groups.msn.com, MoreConfirmation of dark matter? NASA/STScI. These are Hubble images http://groups.msn.com/AstrophysicsGroupWest/moreconfirmationofdarkmatter.msnw
Extractions: var nEditorialCatId = 297; MSN Home My MSN Hotmail Shopping ... Money Web Search: var zflag_nid="346"; var zflag_cid="27"; var zflag_sid="4"; var zflag_width="728"; var zflag_height="90"; var zflag_sz="14"; Groups Groups Home My Groups Language ... Help Astrophysics Group - West AstrophysicsGroupWest@groups.msn.com What's New Join Now HOME PAGE Become A Member of Our Site ... Tools More Confirmation of Dark Matter? NASA/STScI These are Hubble images of three of the most distant supernovae known. By tracking these exploding stars, astronomers can trace the expansion rate of the universe and determine how it is affected by "dark matter." A Closer Look At Space Observations strongly suggest a strange, repulsive dark force dominating the whole universe. It may prove to be the primary element of space itself, and its accelerating the recession of the galaxies away from each other, faster and faster. It is theorized that around 70 percent of our universe may be made up of this "dark energy." And most of whats left is being called "dark matter." The very tiny amount of what remains is what we are familiar with, galaxies of suns, visible energy, planets, and you and me. Adam Riess of the Space Telescope Science Institute has been quoted as saying that, "We still have almost no clue what it is." It is called "dark energy" and "dark matter" because, even though we notice what we feel are the effects of this mysterious force and unknown material, we are unable to see it.
Astrophysics Group - West Astrophysics Group West, astrophysicsgroupwest@groups.msn.com, MoreConfirmation of dark matter? NASA/STScI. These are Hubble images http://groups.msn.com/astrophysicsgroupwest/moreconfirmationofdarkmatter.msnw
Extractions: var nEditorialCatId = 297; MSN Home My MSN Hotmail Shopping ... Money Web Search: var zflag_nid="346"; var zflag_cid="27"; var zflag_sid="4"; var zflag_width="728"; var zflag_height="90"; var zflag_sz="14"; Groups Groups Home My Groups Language ... Help Astrophysics Group - West astrophysicsgroupwest@groups.msn.com What's New Join Now HOME PAGE Become A Member of Our Site ... Tools More Confirmation of Dark Matter? NASA/STScI These are Hubble images of three of the most distant supernovae known. By tracking these exploding stars, astronomers can trace the expansion rate of the universe and determine how it is affected by "dark matter." A Closer Look At Space Observations strongly suggest a strange, repulsive dark force dominating the whole universe. It may prove to be the primary element of space itself, and its accelerating the recession of the galaxies away from each other, faster and faster. It is theorized that around 70 percent of our universe may be made up of this "dark energy." And most of whats left is being called "dark matter." The very tiny amount of what remains is what we are familiar with, galaxies of suns, visible energy, planets, and you and me. Adam Riess of the Space Telescope Science Institute has been quoted as saying that, "We still have almost no clue what it is." It is called "dark energy" and "dark matter" because, even though we notice what we feel are the effects of this mysterious force and unknown material, we are unable to see it.
Nat L Academies Press, Astronomy And Astrophysics In The New SEARCH THIS BOOK 8 chapter(s) found with a hit on dark matter. Front matter,ixxvi. 1 Report of the Panel on High-Energy Astrophysics from Space, 17-64. http://www.nap.edu/nap-cgi/chaphits.cgi?term=dark matter&isbn=0309070376
Extractions: Aztec, Albuquerque Convention Center Max Tegmark (University of Pennsylvania) I summarize the latest constraints on dark matter and dark energy from the cosmic microwave background, large-scale structure, lensing, LyA forest clustering, etc, focusing on the following questions: By postulating complicated unseen matter with sufficiently many free parameters, one can fit almost any observational data, so how can we test the underlying physics in a model-independent way? What current and upcoming cosmological constraints can be robustly connected with dark matter properties that can be probed experimentally? Eric Gawiser (Physics Dept., U.C. San Diego) The Hot Big Bang plus inflation is the standard model of the early universe. I will present a new cosmological model which uses the observed cosmic dark energy as initial conditions for an inflationary phase which mimics a Hot Big Bang. This inflationary phase (dubbed rejuvenation) will be produced if the effective cosmological constant increases with time. The universe undergoes superexponential expansion until it resumes radiation domination, leaving it identical to a Hot Big Bang in all measurable respects but avoiding an initial singularity. This process can produce adiabatic density perturbations as favored by recent observations of Cosmic Microwave Background anisotropy, although a blue tilt to the primordial power spectrum is predicted.
Session V16 - Theoretical Astrophysics And Cosmology. Session V16 Theoretical Astrophysics and Cosmology. MIXED session, Tuesday morning,May 02 202C, LBCC. V16.005 The Large-Scale US dark matter Axion Search. http://www.eps.org/aps/meet/APR00/baps/abs/S8150.html
Extractions: 202C, LBCC S.O. Nelson, H.R. Weller, R.S. Canon, E.C. Schreiber, K. Saburov, S. Gaff, E.A. Wulf (Duke University and TUNL), J.H. Kelley, D.R. Tilley (North Carolina State University and TUNL), R.M. Prior, M. Spraker (North Georgia State University and TUNL) Uwe Greife (Department of Physics, Colorado School of Mines), LUNA Collaboration, NABONA Collaboration M. Joffre (Univ. of Chicago), P. Fischer (Univ. of Michigan), J. Frieman (Univ. of Chicago/ Fermilab), T. McKay (Univ. of Michigan), J.J. Mohr (Univ. of Chicago), R.C. Nichol (CMU), D. Johnston (Univ. of Chicago), E. Sheldon (Univ. of Michigan), C. Cantaloupo, G. Griffin, J. Peterson, A.K. Romer (CMU) We present results from a weak lensing survey of an X-ray luminosity-limited sample of 18 nearby (z There is some observational evidence for an excess angular correlation between the distribution of galaxies and much more distant QSOs. It was suggested that such a correlation can be explained by weak gravitational lensing of the QSO image by intermediate galaxies. However there is a considerable quantitative disagreement between observations and theoretical predictions.
San Pedro Workshop Page dark matter AND GRAVITATIONAL LENSING THE SECOND PRINCETON PUC WORKSHOP ON ASTROPHYSICS.to be held in San Pedro de Atacama, Chile, on July 19-22, 2000. http://www.astro.puc.cl/~workshop/2000/
Extractions: This meeting intends to bring together Chilean and foreign astronomers working in Chile, plus a small number of participants from abroad (up to a total of about 45 people), with some 15 experts from around the world to discuss recent advances in the study of dark matter and on how to attack the problem under the new view angle made accessible by the most recent observational developments. TOPICS The talks will focus on the study of dark matter via the gravitational lensing effect and will expose the most recent developments in areas including: Galactic microlensing Galaxy-galaxy lensing Mass-to-light ratios of clusters and single galaxies Distribution of dark matter in galaxy halos Weak lensing by Large Scale Structures Lens models and quasar time delays Use of future instrumentation for the study of dark matter (ALMA, NGST)
