Cosmologists produce new maps of dark matter dynamics | UoP News
http://uopnews.port.ac.uk/2017/07/25/cosmologists-produce-new-maps-of-dark-matter-dynamics/

New maps of dark matter dynamics in the Universe have been produced by a team of international cosmologists.

Using advanced computer modelling techniques, the research team has translated the distribution of galaxies into detailed maps of matter
streams and velocities for the first time. The research was carried out by leading cosmologists from the UK, France and Germany.

The researchers used legacy survey data obtained during 2000 – 2008 from the Sloan Digital Sky Survey (SDSS), a major three-dimensional
survey of the Universe. The survey has deep multi-colour images of one fifth of the sky and spectra for more than 900,000 galaxies.

The new dark matter maps cover the Northern Sky up to a distance of 600 megaparsecs, which is the equivalent of looking back about two
billion years. The researchers used a set of phase-space analysis tools and built on research from 2015, which reconstructed the initial
conditions of the nearby Universe.

The Story of a Boring Encounter with a Black Hole
http://aasnova.org/2017/07/24/the-story-of-a-boring-encounter-with-a-black-hole/

Remember the excitement three years ago before the gas cloud G2’s encounter with the supermassive black hole at the center of our galaxy, Sgr A*?
Did you notice that not much was said about it after the fact? That’s because not much happened — and a new study suggests that this isn’t surprising.

G2, an object initially thought to be a gas cloud, was expected to make its closest approach to the 4.6-million-solar-mass Sgr A* in 2014. At the pericenter
of its orbit, G2 was predicted to pass as close as 36 light-hours from the black hole. This close brush with such a massive black hole was predicted to tear
G2 apart, causing much of its material to accrete onto Sgr A*. It was thought that this process would temporarily increase the accretion rate onto the black
hole relative to its normal background accretion rate, causing Sgr A*’s luminosity to increase for a time.

Instead, Sgr A* showed a distinct lack of fireworks, with very minimal change to its brightness after G2’s closest approach. This “cosmic fizzle” has raised
questions about the nature of G2: was it really a gas cloud? What else might it have been instead? Now, a team of scientists led by Brian Morsony (University
of Maryland and University of Wisconsin-Madison) have run a series of simulations of the encounter to try to address these questions.

Dark matter is likely ‘cold,’ not ‘fuzzy,’ scientists report after new simulations | UW News
http://www.washington.edu/...atter-is-likely-cold-not-fuzzy-scientists-report-after-new-simulations/

Dark matter is the aptly named unseen material that makes up the bulk of matter in our universe. But what dark matter is made of is a matter of debate.

Scientists have never directly detected dark matter. But over decades, they have proposed a variety of theories about what type of material — from new
particles to primordial black holes — could comprise dark matter and explain its many effects on normal matter. In a paper published July 20 in the journal
Physical Review Letters, an international team of cosmologists uses data from the intergalactic medium — the vast, largely empty space between galaxies —
to narrow down what dark matter could be.

The team’s findings cast doubt on a relatively new theory called “fuzzy dark matter,” and instead lend credence to a different model called “cold dark matter.”
Their results could inform ongoing efforts to detect dark matter directly, especially if researchers have a clear idea of what sorts of properties they should
be seeking.

Mapping Dark Mattersu201727 | www.cfa.harvard.edu/
https://www.cfa.harvard.edu/news/su201727

Galaxies generally reside at the centers of vast clumps of dark matter called haloes because they surround the clusters of galaxies. Gravitational lensing
of more distant galaxies by dark matter haloes offers a particularly unique and powerful probe of the detailed distribution of dark matter. So-called strong
gravitational lensing creates highly distorted, magnified and occasionally multiple images of a single source; so-called weak lensing results in modestly yet
systematically deformed shapes of background galaxies that can also provide robust constraints on the distribution of dark matter within the clusters.

CfA astronomers Annalisa Pillepich and Lars Hernquist and their colleagues compared gravitationally distorted Hubble images of the galaxy cluster Abell 2744
and two other clusters with the results of computer simulations of dark matter haloes. They found, in agreement with key predictions in the conventional dark
matter picture, that the detailed galaxy substructures depend on the dark matter halo distribution, and that the total mass and the light trace each other.
They also found a few discrepancies: the radial distribution of the dark matter is different from that predicted by the simulations, and the effects of tidal
stripping and friction in galaxies are smaller than expected, but they suggest these issues might be resolved with more precise simulations. Overall, however,
the standard model of dark matter does an excellent and reassuring job of describing galaxy clustering.

Hubble’s Hunting Dog Galaxy
https://www.nasa.gov/image-feature/goddard/2017/hubbles-hunting-dog-galaxy

Tucked away in the small northern constellation of Canes Venatici (The Hunting Dogs) is the galaxy NGC 4242, shown here as seen by the NASA/ESA
Hubble Space Telescope. The galaxy lies some 30 million light-years from us. At this distance from Earth, actually not all that far on a cosmic scale,
NGC 4242 is visible to anyone armed with even a basic telescope, as British astronomer William Herschel found when he discovered the galaxy in 1788.

Study teams comb through NASA’s wish list for new telescope – Spaceflight Now
https://spaceflightnow.com/2017/07/21/study-teams-comb-through-nasas-wish-list-for-a-new-telescope/

Scientists outlining four concepts for a powerful new space telescope that could launch in the 2030s this week said improvements in optics, detectors and access to huge new
rockets like NASA’s Space Launch System could revolutionize the way astronomers observe potentially habitable planets, black holes, and the earliest galaxies in the universe.

It is likely NASA will only be able to afford one of the four proposed flagship observatories, and the space agency will take the advice of an independent review by the National
Research Council in 2020 on which type of telescope should receive highest priority.

New Type Ia supernova discovered using gravitational lensing
https://phys.org/news/2017-07-ia-supernova-gravitational-lensing.html

Using gravitational lensing, an international team of astronomers has detected a new Type Ia supernova. The newly discovered lensed supernova was
found behind the galaxy cluster known as MOO J1014+0038. The findings were detailed in a paper published July 14 on the arXiv pre-print repository.

Recently, a team of researchers led by David Rubin of the Space Telescope Science Institute in Baltimore, Maryland, have used one such massive galaxy
cluster to reveal the presence of a new type Ia supernova. This type of supernovae can be found in binary systems in which one of the stars is a white
dwarf. Type Ia supernovae are important for the scientific community as they offer essential clues into evolution of stars and galaxies.

Rubin's team monitored 12 massive galaxy clusters with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) as part of the Supernova Cosmology
Project "See Change" program. These observations were complemented by an analysis of images available in the Massive and Distant Clusters of WISE Survey.

Hunting Molecules with the MWA - ICRAR
https://www.icrar.org/hunting-molecules/

Astronomers have used an Australian radio telescope to observe molecular signatures from stars, gas and
dust in our galaxy, which could lead to the detection of complex molecules that are precursors to life.

Using the Murchison Widefield Array (MWA), a radio telescope located in the Murchison region of Western
Australia, the team successfully detected two molecules called the mercapto radical (SH) and nitric oxide (NO).