NEBULA: Zhusta!

VIRGO: Massive Arecibo Study Subtracts The Galaxy; Reveals A Pristine Universe
http://www.forbes.com/...recibo-study-subtracts-the-galaxy-reveals-a-pristine-universe/#42def3e31d0d

There's a big problem with measuring CMB radiation: no matter where we look, there's intervening matter in the way. It's true that the hotter something is, the more energy
and light it radiates away. The Big Bang's leftover glow is so cold - just 2.725 K, with fluctuations on the scale of 10s or 100s of µK - that even the coldest interstellar
gas and dust can cause foreground contamination. Even when observed with the Planck satellite, the most advanced, sophisticated mapping tool every constructed for this
leftover glow, the foreground emissions from the Milky Way are still a terrible source of pollution and noise.

The smallest-scale features in light of very particular frequencies (between 22 and 90 GHz) are where some of the most intricate information about the pristine Universe lies.
The overdense regions (which correspond to blue, cold spots in the fancy image of the CMB) will someday grow into galaxies, clusters and even larger structures. But in order
to understand how this works in our Universe, we need a full-sky map, not merely a map of the sky except where the galactic plane is. The key, and the hard problem, is to
properly account for the full suite of the galactic foregrounds. After years of work by hundreds of people, we thought we had done it properly. Yet continued observations
showed that problems remained, and that the galactic subtraction was incomplete.

In particular, there were two key puzzles that needed to be solved:

Why are the magnetic field lines of the galaxy aligned with the orientation of neutral hydrogen? (Which is puzzling, because only charged particles, not neutral ones,
should be aligned with a magnetic field.)

And why is that neutral hydrogen associated with the polarization of the CMB? (Which is puzzling because the hydrogen is only hundreds of light years away, but the CMB is
billions of light years away, and they shouldn't affect each other.)

The answer is, of course, that these can't be the full story. The leftover glow from the Big Bang can't just randomly align with something happening in our own galaxy; there
has to be something additional in the galaxy responsible for it! And that means, unfortunately, that our previous calculations for what the Universe looked like behind
the Milky Way was flawed in a very fundamental way.

Thankfully, a new study by Gerrit Verschuur and Joan Schmelz using the Arecibo radio telescope was able to study the galactic plane in great detail, in an attempt to uncover
the cause of the radiation. By viewing a number of foreground, galactic sources at a variety of frequencies, they were able to compare what the radio data showed with what
the theory predicted. Quite clearly, there was a terrible fit, showing that the previously introduced model of the galaxy was missing a component.

But if you added in a population of free electrons at relatively warm temperatures (100-300 K), everything gets resolved. The magnetic field lines are aligned with galactic
hydrogen because there are free, charged particles influencing the neutral hydrogen. The neutral hydrogen isn't aligned with the polarization of the CMB; the free electrons
are aligned with the electromagnetic radiation's polarization, and they in turn interact with neutral hydrogen. And in the graph above, rather than a downward-sloping line,
there ought to be a straight, horizontal line that the data follows. You will notice the data doesn't follow it perfectly, and that's good! The leftover signal on top of
that - the up-and-down wiggles - ought to correspond to the actual fluctuations in the CMB: the Big Bang's leftover glow.

NASA Selects Mission to Study Black Holes, Cosmic X-ray Mysteries
https://www.nasa.gov/press-release/nasa-selects-mission-to-study-black-holes-cosmic-x-ray-mysteries

NASA has selected a science mission that will allow astronomers to explore, for the first time, the hidden details of some of the most extreme
and exotic astronomical objects, such as stellar and supermassive black holes, neutron stars and pulsars.

Objects such as black holes can heat surrounding gases to more than a million degrees. The high-energy X-ray radiation from this gas can be polarized –
vibrating in a particular direction. The Imaging X-ray Polarimetry Explorer (IXPE) mission will fly three space telescopes with cameras capable of
measuring the polarization of these cosmic X-rays, allowing scientists to answer fundamental questions about these turbulent and extreme environments
where gravitational, electric and magnetic fields are at their limits.

The mission, slated for launch in 2020, will cost $188 million. This figure includes the cost of the launch vehicle and post-launch operations and data
analysis. Principal Investigator Martin Weisskopf of NASA’s Marshall Space Flight Center in Huntsville, Alabama, will lead the mission. Ball Aerospace
in Broomfield, Colorado, will provide the spacecraft and mission integration. The Italian Space Agency will contribute the polarization sensitive X-ray
detectors, which were developed in Italy.

USRA | Arecibo Observatory casts new light on cosmic microwave background observed by WMAP and PLANCK spacecraft: Bringing scientists one step closer to understanding the small-scale structure in the cosmic microwave background
http://www.usra.edu/news/pr/2017/cosmicmicrowave/

Arecibo Observatory observations of galactic neutral hydrogen structure confirm the discovery of an unexpected contribution to the measurements of the cosmic microwave
background observed by the WMAP and Planck spacecraft. An accurate understanding of the foreground (galactic) sources of radiation observed by these two spacecraft is
essential for extracting information about the small-scale structure in the cosmic microwave background believed to be indicative of events in the early universe.

The new source of radiation in the 22 to 100 GHz range observed by WMAP and Planck appears to be emission from cold electrons (known as free-free emission). While
cosmologists have corrected for this type of radiation from hot electrons associated with galactic nebulae where the source temperatures are thousands of degrees,
the new model requires electron temperatures more like a few 100 K.

The spectrum of the small-scale features observed by WMAP and Planck in this frequency range is very nearly flat - a finding consistent with the sources being associated
with the Big Bang. At first glance it appears that the spectrum expected from the emission by cold galactic electrons, which exist throughout interstellar space, would
be far too steep to fit the data. However, if the sources of emission have a small angular size compared with the beam width used in the WMAP and Planck spacecraft, the
signals they record would be diluted. The beam widths increase with lower frequency, and the net result of this "beam dilution" is to produce an apparently flat spectrum
in the 22 to 100 GHz range.

The model invoking the emission from cold electrons not only gives the observed flat spectrum usually attributed to cosmic sources but also predicts values for the angular
scale and temperature for the emitting volumes. Those predictions can then be compared with observations of galactic structure revealed in the Galactic Arecibo L-Band Feed
Array (GALFA) HI survey.

"The interstellar medium is much more surprising and important than we have given it credit for," noted Dr. Joshua Peek, an astronomer at the Space Telescope Science
Institute and a co-investigator on the GALFA-HI survey. "Arecibo, with its combination of large area and high resolution, remains a spectacular and cutting edge tool
for comparing ISM maps to cosmological data sets."

The angular scales of the smallest features observed in neutral hydrogen maps made at Arecibo and the temperature of the apparently associated gas both match the model
calculations extremely well. So far only three well-studied areas have been analyzed in such detail, but more work is being planned.

"It was the agreement between the model predictions and the GALFA-HI observations that convinced me that we might be onto something," noted Dr. Joan Schmelz, Director,
Universities Space Research Association (USRA) at Arecibo Observatory and a coauthor on the paper. "We hope that these results help us understand the true cosmological
nature of Planck and WMAP data."

The data suggest that the structure and physics of diffuse interstellar matter, in particular of cold hydrogen gas and associated electrons, may be more complex than
heretofore considered. Such complexities need to be taken into account in order to produce better foreground masks for application to the high-frequency continuum
observations of Planck and WMAP in the quest for a cosmologically significant signal.

Working at Subaru Telescope 3. Instrumentation & Electronics
https://www.youtube.com/watch?v=shCMkZI9LuQ

USRA | The Mystery of Part-Time Pulsars
http://www.usra.edu/news/pr/2017/pulsar/

A new discovery has upended the widely held view that all pulsars are orderly ticking clocks of the universe.
A survey done at the Arecibo Observatory in Puerto Rico has fortuitously discovered two extremely strange pulsars
that undergo a "cosmic vanishing act." Sometimes they are there, and then for very long periods of time, they are not.

Recognizing the existence of this strange behavior was fortuitous in itself. It took great patience on the part of
a team of radio astronomers at Jodrell Bank in the UK led by Professor Andrew Lyne of the University of Manchester
to confirm the existence of these mostly invisible pulsars.

Intermittent pulsars are a rarely observed population of pulsars, which have two states -- one when they pulse like
normal pulsars (the ON state), and another when they mysteriously fail to work, producing no radio waves at all (the
OFF state). "They switch instantaneously between the states," notes Lyne. "They're ON and then they're gone,
disappearing without any apparent warning."

A 34-member pulsar study team, including Dr. Andrew Seymour, a USRA postdoc at Arecibo, used the 7-beam receiver to
conduct routine pulsar searches in what they call the PALFA (Pulsar Arecibo L-Band Feed Array) Survey. The two recently
discovered intermittent pulsars spend most of their time in the OFF state. Three other similar pulsars are also known,
but they are mostly ON.

VIRGO: no já se právě vylekala (pozitivně), že se chystá nějaký great oznámení, co se toho týče... :) no takže takhle taky dobrý :)

VIRGO: to je nádhera, i ta andromeda níže! krása prostě :)

VIRGO:
VIRGO: co to co to co to??