Are We Inside a ‘Galactic Transport System’?

Wormhole simulation - Credits Davide and Paolo Salucci.

Wormhole simulation – Credits Davide and Paolo Salucci.

In theory, the Milky Way could be a “galactic transport system”

Based on the latest evidence and theories our galaxy could be a huge wormhole (or space-time tunnel such as the one depicted in the recent film Interstellar) and, if that were true, it would be “stable and navigable”. This is the hypothesis put forward in a study published in Annals of Physics and conducted with the participation of SISSA in Trieste [citation below]. Read More →

Cosmic Battle and the Future of the Universe

Cosmologists use galaxies observed by the Sloan Digital Sky Survey to study the nature of dark energy – CREDIT: Sloan Digital Sky Survey

Cosmologists use galaxies observed by the Sloan Digital Sky Survey to study the nature of dark energy – CREDIT: Sloan Digital Sky Survey

New research offers a novel insight into the nature of dark matter and dark energy and what the future of our universe might be. Researchers in Portsmouth and Rome have found hints that dark matter, the cosmic scaffolding on which our universe is built, is being slowly erased, swallowed up by dark energy. A cosmic battle of sorts.

Read More →

What White Dwarfs Can Tell Us About the Universe

Birth of a white dwarf (bright spot at the center) in the Dumbbell Nebula./ Credit: Telescopio Joan Oro - Observatori Astronomic del Montsec

Birth of a white dwarf (bright spot at the center) in the Dumbbell Nebula./ Credit: Telescopio Joan Oro – Observatori Astronomic del Montsec

Researchers from Europe and the U.S. have ruled out a multitude of possible parameters for dark photons – a type of dark matter and energy – with the help of white dwarfs. In some aspects, the shining of these dying stars gives more information on dark forces than is provided by earth-based laboratories. The journal ‘Physical Review D’ has published the study [citation below]. Read More →

A Closer Look at Galaxy Cluster Abell 520

Data from NASA’s Chandra X-ray Observatory show the hot gas in the colliding clusters colored in green. The gas provides evidence that a collision took place. Optical data from NASA’s Hubble Space Telescope and the Canada-France-Hawaii Telescope (CFHT) in Hawaii are shown in red, green, and blue. Starlight from galaxies within the clusters, derived from observations by the CFHT and smoothed to show the location of most of the galaxies, is colored orange.

The blue-colored areas pinpoint the location of most of the mass in the cluster, which is dominated by dark matter. Dark matter is an invisible substance that makes up most of the universe’s mass. The dark-matter map was derived from the Hubble observations, by detecting how light from distant objects is distorted by the cluster galaxies, an effect called gravitational lensing. The blend of blue and green in the center of the image reveals that a clump of dark matter (which can be seen by mousing over the image) resides near most of the hot gas, where very few galaxies are found.

This finding confirms previous observations of a dark-matter core in the cluster announced in 2007. The result could present a challenge to basic theories of dark matter, which predict that galaxies should be anchored to dark matter, even during the shock of a powerful collision.

Source: NASA

Image Credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University)

Meet I Zw 18: A Dwarf Galaxy

The Center of Astrophysics of the University of Porto recently came up with an analysis that seriously calls into question the current model of galactic formation. Polychronis Papaderos represented the CAUP, and with his Swedish colleague Göran Östlin, Papderos examined data from the Hubble Space Telescope to better understand the I Zw 18 dwarf galaxy. That particular object has received a lot of attention, and it is one of the few places where star-forming activity can be readily observed.

I Zw 18 region. (Credit: Image courtesy of Centro de Astrofísica da

For a long time, astrophysicists have simply assumed that stars were emitting light from gas structures. These structures occupied the same region as the stars that were emitting the light. The research suggests that galaxies that undergo active starbursts don’t follow this rule. Instead, nebula gases might actually be emitting around half of the total light in question. Since star mass is often calculated from the galaxy’s total luminosity, the idea that nebular emissions account for so much light means that many of these calculations could be totally off. One could also surmise that since I Zw 18 is young, the galaxy is acting the way many objects did shortly after the Big Bang. Many of the stars there have been around for less than 1 billion years. It will be interesting to watch this galaxy in the years ahead.

Reference:

Papaderos, P., & Östlin, G. (2012). I Zw 18 as morphological paradigm for rapidly assembling high-galaxies Astronomy & Astrophysics, 537 DOI: 10.1051/0004-6361/201117551

Izotov, Y., Chaffee, F., Foltz, C., Thuan, T., Green, R., Papaderos, P., Fricke, K., & Guseva, N. (2001). A Spectroscopic Study of Component C and the Extended Emission around I Zw 18 The Astrophysical Journal, 560 (1), 222-235 DOI: 10.1086/322494

Image Credit: Hubble

ResearchBlogging.org