A UK-led team of astronomers reports today (August 4th) in Nature that they have tracked down an elusive population of black holes growing rapidly hidden behind clouds of dust. Their results suggest that most black hole growth takes place in dusty galaxies, solving astronomer’s headaches, as until now, the cosmic x-ray background suggested the existence of more growing black holes than they could find.
Growing black holes, known as quasars, are some of the brightest objects in the Universe and are seen by the light emitted as gas and dust spiral into the black hole. Quasars are situated in the inner-most regions of galaxies and can consume the equivalent mass of between ten and a thousand stars in one year! Astronomers believe that all quasars are surrounded by a dusty ring which hides them from sight on Earth in about half of cases.
However, examining the cosmic x-ray background, which is made up primarily of the emissions from quasars, astronomers realised that there should be many more obscured quasars than currently known. Objects surrounded by dust are hard to see with visible light, so the astronomers looked at infrared wavelengths, which are less likely to be reflected away. Using NASA’s Spitzer Space Telescope’s First Look Data, they were able to find a new population of obscured quasars. The new quasars have no spectra that can be seen and are thought to be hidden behind the dust of the galaxy itself rather than just a dust ring. The presence of lots of dust in a galaxy indicates that stars are still forming there. The researchers found 21 examples of these lost quasars in a relatively small patch of sky. All of the objects were confirmed as quasars by the National Radio Astronomy Observatorys Very Large Array radio telescope, New Mexico, and the Particle Physics and Astronomy Research Councils William Hershel Telescope on La Palma.
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy