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Categories: Physics: Acoustics and Ultrasound, Space: Structures and Features

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As their name suggests, ultradiffuse galaxies, or UDGs, are dwarf galaxies whose stars are spread out over a vast region, resulting in extremely low surface brightness, making them very difficult to detect. An international team of astronomers reports it has used sophisticated simulations to detect a few 'quenched' UDGs in low-density environments in the universe. A quenched galaxy is one that does not form stars.

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Researchers have conducted the first demonstration of a faster and more accurate way to calibrate certain kinds of microphones. The technique, which uses lasers to measure the velocity at which a microphone's diaphragm vibrates, performs well enough to overtake one of the main calibration methods used.

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Researchers have uncovered the physical and chemical effects of the impact of a protostellar jet in the interior of the Orion Nebula. The observations show evidence of compression and heating produced by the shock front, and the destruction of dust grains, which cause a dramatic increase in the gas phase abundance of the atoms of iron, nickel, and other heavy elements in the Orion Nebula.

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Researchers have developed three designs for compact speaker systems that control the direction of sound more efficiently than previous models. For each speaker, the scientists were able to manipulate the timing and strength of the outgoing sound waves. They combined multiple speakers together into an array and used the constructive and destructive interference of sound waves to their advantage.

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While moving around within the gas in the interstellar medium, cosmic rays kickstart the background protons, which causes a collective plasma wave movement akin to ripples on a lake. The big question is how cosmic rays deposit their momentum into the background plasma. Plasma astrophysicists review recent developments within the field of studying the streaming instability triggered by cosmic rays, which likely have more impacts on galactic dynamics and the star formation cycle than previously known.

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While doctors have used low-intensity ultrasound as a medical imaging tool since the 1950s, experts are now using and extending models that help capture how high-intensity focused ultrasound (HIFU) can work on a cellular level.

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Astronomers calculate that the Oort Cloud may be home to more visiting objects than objects that belong to our solar system.

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Astronomers have succeeded in quantifying the proton and electron components of cosmic rays in a supernova remnant. At least 70% of the very-high-energy gamma rays emitted from cosmic rays are due to relativistic protons, according to the novel imaging analysis of radio, X-ray, and gamma-ray radiation. The acceleration site of protons, the main components of cosmic rays, has been a 100-year mystery in modern astrophysics.

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With wind generation one of the fastest-growing renewable energy sectors in the world, experts are using machine learning and other signal processing techniques to characterize annoying noise features from wind farms. Two new publications from the ongoing Wind Farm Noise Study take another step towards improving wind turbine noise assessment methods, guidelines and wind turbine design to make wind energy more acceptable to surrounding communities.

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Prediction models based on clinical characteristics and imaging findings may help reduce the false-positive rate in women with dense breasts who undergo supplemental breast cancer screening with MRI, according to a new study.

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A region of active star formation in the constellation Ophiuchus is giving astronomers new insights into the conditions in which our own solar system was born. In particular, a new study of the Ophiuchus star-forming complex shows how our solar system may have become enriched with short-lived radioactive elements.

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A different kind of design for absorbing vibrations could help better soundproof walls and make vehicles more streamlined, a new study shows.

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When we speak, we use our auditory and somatosensory systems to monitor the results of the movements of our tongue or lips. Since we cannot typically see our own faces and tongues while we speak, however, the potential role of visual feedback has remained less clear. Researchers explore how readily speakers will integrate visual information about their tongue movements during a speech motor learning task.

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A new study suggests that previously displaced gases can re-accrete onto galaxies, potentially slowing down the process of galaxy death caused by ram pressure stripping, and creating unique structures more resistant to its effects.

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Researchers have demonstrated a low-cost technique for retrieving nanowires from electronic devices that have reached the end of their utility and then using those nanowires in new devices. The work is a step toward more sustainable electronics.

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Engineers developed a soft, stretchy ultrasound patch that can be worn on the skin to monitor blood flow through vessels deep inside the body. Such a device can make it easier to detect cardiovascular problems, like blockages in the arteries that could lead to strokes or heart attacks.

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A new survey of our home galaxy, the Milky Way, combines the capabilities of the Very Large Array and the Effelsberg telescope in Germany to provide astronomers with valuable new insights into how stars much more massive than the Sun are formed.

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Astronomersand engineers are building a new kind of astronomical telescope. SuperBIT flies above 99.5% of the Earth's atmosphere, carried by a helium balloon the size of a football stadium. The telescope will make its operational debut next April and when deployed should obtain high-resolution images rivaling those of the Hubble Space Telescope.

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The final stage of cataclysmic explosions of dying massive stars, called supernovae, could pack an up to six times bigger punch on the surrounding interstellar gas with the help of cosmic rays, according to a new study.

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Engineers made a pneumatic RAM chip using microfluidic valves instead of electronic transistors. The valves remain sealed against a pressure differential even when disconnected from an air supply line, creating trapped pressure differentials that function as memories and maintain the states of a robot's actuators. Dense arrays of these valves can perform advanced operations and reduce the expensive, bulky, and power-consuming electronic hardware typically used to control pneumatic robots.