четверг, 4 июля 2019 г.

Fast Radio Burst Pinpointed to Distant Galaxy


Owens Valley Radio Observatory, together with w. m. keck observatory, is providing new clues in an ongoing cosmic mystery. Credit: Caltech/Ovro/G. Hallinan


Maunakea, Hawaii – Fast radio bursts (FRBs) are among the most enigmatic and powerful events in the cosmos. Around 80 of these events—intensely bright millisecond-long bursts of radio waves coming from beyond our galaxy—have been witnessed so far but their causes remain unknown.

In a rare feat, researchers at Caltech’s Owens Valley Radio Observatory (OVRO) have now caught a new burst, called FRB 190523, and, together with the W. M. Keck Observatory in Hawaii, have pinpointed its origins to a galaxy 7.9 billion light-years away. Identifying the galaxies from which these radio bursts erupt is a critical step toward solving the mystery of what triggers them.



Finding the host galaxies of FRBs is not easy. Before this new discovery, only one other burst, called FRB 121102, had been localized to a host galaxy. FRB 121102 was reported in 2014 and then later, in 2017, was pinpointed to a galaxy lying 3 billion light-years away. Recently, a second localized FRB was announced on June 27, 2019. Called FRB 180924, this burst was discovered by a team using the Australian Square Kilometer Array Pathfinder and traced to a galaxy about 4 billion light-years away.

FRB 121102 was easiest to find because it continues to burst every few weeks. Most FRBs, however—including the Australian and OVRO finds—just go off once, making the job of finding their host galaxies harder.


“Finding the locations of the one-off FRBs is challenging because it requires a radio telescope that can both discover these extremely short events and locate them with the resolving power of a mile-wide radio dish,” says Vikram Ravi, a new assistant professor of astronomy at Caltech who works with the radio telescopes at OVRO, which is situated east of the Sierra Nevada mountains in California.


The team then conducted follow-up observations using Keck Observatory’s Low Resolution Imaging Spectrometer (LRIS) to determine the properties of FRB 190523’s host galaxy.


The LRIS data revealed that the host galaxy for FRB 190523 is similar to our Milky Way. This is a surprise because the previously located FRB 121102 originates from a dwarf galaxy that is forming stars more than a hundred times faster than the Milky Way.


“This finding tells us that every galaxy, even a run-of-the-mill galaxy like our Milky Way, can generate an FRB,” says Ravi.


The discovery also suggests that a leading theory for what causes FRBs—the eruption of plasma from young, highly magnetic neutron stars, or magnetars—may need to be rethought.


“The theory that FRBs come from magnetars was developed in part because the earlier FRB 121102 came from an active star-forming environment, where young magnetars can be formed in the supernovae of massive stars,” says Ravi. “But the host galaxy of FRB 190523 is more mellow in comparison. “



The Deep Synoptic Array ten-antenna prototype (DSA-10) searches for fast radio bursts within a sky-area the size of 150 full moons (left). Within this area, the DSA-10 can locate these bursts with immense resolving power, isolating them to regions containing just one galaxy (middle). This feat was achieved for the fast radio burst called FRB 190523, detected by DSA-10 on May 23, 2019. The right panel shows the time profile of the burst above its radio spectrum. Credit: Caltech/OVRO/V. Ravi 


Ultimately, to solve the mystery of FRBs, astronomers hope to uncover more examples of their host galaxies.  


“With the full Deep Synoptic Array, we are going to find and localize FRBs every few days,” says Gregg Hallinan, the director of OVRO and a professor of astronomy at Caltech. “This is an exciting time for FRB discoveries.”


“We’re very excited about the new capabilities to find these enigmatic bursts and we look forward to continuing to provide the critical follow-up data that tell us how distant these objects are and what environments they live in,” says John O’Meara, chief scientist at Keck Observatory.


The researchers also say that FRBs can be used to study the amount and distribution of matter in our universe, which will tell us more about the environments in which galaxies form and evolve. As radio waves from FRBs head toward Earth, intervening matter causes some of the wavelengths to travel faster than others; the wavelengths become dispersed in the same way that a prism spreads apart light into a rainbow. The amount of dispersion tells astronomers exactly how much matter there is between the FRB sources and Earth. 


“Most matter in the universe is diffuse, hot, and outside of galaxies,” says Ravi. “This state of matter, although not ‘dark,’ is difficult to observe directly. However, its effects are clearly imprinted on every FRB, including the one we detected at such a great distance.” 



The Nature study, titled, “A fast radio burst localized to a massive galaxy,” was funded by NSF and Caltech. Other Caltech authors include: Morgan Catha, electronics engineer at OVRO; Larry D’Addario, system engineer; George Djorgovski, professor of astronomy; Richard Hobbs, software developer at OVRO; Jonathon Kocz, digital research engineer; Shri Kulkarni, the George Ellery Hale Professor of Astronomy and Planetary Science; Jun Shi, postdoctoral scholar; Harish Vedantham, a former postdoctoral scholar now at ASTRON, the Netherlands Institute for Radio Astronomy; Sandy Weinreb, visiting associate in astronomy; and David Woody, assistant director of OVRO.







About LRIS




The Low Resolution Imaging Spectrometer (LRIS) is a very versatile visible-wavelength imaging and spectroscopy instrument commissioned in 1993 and operating at the Cassegrain focus of Keck I. Since it has been commissioned it has seen two major upgrades to further enhance its capabilities: addition of a second, blue arm optimized for shorter wavelengths of light; and the installation of detectors that are much more sensitive at the longest (red)wavelengths. Each arm is optimized for the wavelengths it covers. This large range of wavelength coverage, combined with the instrument’s high sensitivity, allows the study of everything from comets (which have interesting features in the ultraviolet part of the spectrum), to the blue light from star formation, to the red light of very distant objects. LRIS also records the spectra of up to 50 objects simultaneously, especially useful for studies of clusters of galaxies in the most distant reaches, and earliest times, of the universe.  LRIS was used in observing distant supernovae by astronomers who received the Nobel Prize in Physics in2011 for research determining that the universe was speeding up in its expansion.




About W.M. Keck Observatory




The W. M. Keck Observatory telescopes are the most scientifically productive on Earth. The two, 10-meter optical/infrared telescopes atop Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors recognize and acknowledge the very significant cultural role that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.




Archive link


Dust storms swirl at the north pole of Mars


ESA — Mars Express Mission patch.


4 July 2019


ESA’s Mars Express has been keeping an eye on local and regional dust storms brewing at the north pole of the Red Planet over the last month, watching as they disperse towards the equator.



Spiral dust storm on Mars

Local and regional storms lasting for a few days or weeks and confined to a small area are common place on Mars, but at their most severe can engulf the entire planet, as experienced last year in a global storm that circled the planet for many months.


It is currently spring in the northern hemisphere of Mars, and water-ice clouds and small dust-lifting events are frequently observed along the edge of the seasonally retreating ice cap.


Many of the spacecraft at Mars return daily weather reports from orbit or from the surface, providing global and local impressions of the changing atmospheric conditions. ESA’s Mars Express observed at least eight different storms at the edge of the ice cap between 22 May and 10 June, which formed and dissipated very quickly, between one and three days.



Mars dust storm in motion

The two cameras onboard the spacecraft, the High Resolution Stereo Camera (HRSC) and the Visual Monitoring Camera (VMC), have been monitoring the storms over the last weeks. The image at the top of this page, taken by HRSC on 26 May, captures a spiral-shaped dust storm, its brown colour contrasting against the white ice of the north polar ice cap below.


Meanwhile the animated sequence (above) was compiled from images of a different storm captured by the VMC over a period of 70 minutes on 29 May. This particular storm started on 28 May and continued to around 1 June, moving towards the equator during that time.



Mars Express

The montage of images (below) shows three different storms developing on 22 May, on 26 May, and between 6 and 10 June. In the latter case, the cameras watched the storm evolve for several days as it moved in an equatorward direction.


At the same time, wispy patches of light-coloured clouds can be seen at the outer margin of the polar cap and also several thousand kilometres away, close to the volcanoes Elysium Mons and Olympus Mons.



Dust storm season on Mars

Together with the MARCI camera onboard NASA’s Mars Reconnaissance Orbiter, Mars Express observed that when the dust storms reached the large volcanoes, orographic clouds – water ice clouds driven by the influence of the volcano’s leeward slope on the air flow – that had previously been developing started to evaporate as a result of the air mass being heated by the influx of dust.



Mars dust storm

These regional dust storms only last a few days; the elevated dust is transported and spread out by global circulation into a thin haze in the lower atmosphere, around 20–40 km altitude. Some traces of dust and clouds remained in the volcanic province into mid-June.


Related links:


Mars Express: http://www.esa.int/Our_Activities/Space_Science/Mars_Express


MARCI: http://www.msss.com/msss_images/date/2019_06.html


HRSC at DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10364/548_read-400/#/gallery/657


HRSC data viewer: http://hrscview.fu-berlin.de/


Mars Webcam: https://www.flickr.com/photos/esa_marswebcam/


Images, Animation, Text, Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO/GCP/UPV/EHU Bilbao.


Best regards, Orbiter.chArchive link


In Your Stride We all know that sugar can give us a burst of…


In Your Stride


We all know that sugar can give us a burst of energy. But glucose – sugar in its basic molecular form – also sustains all the molecular, cellular, and whole-body processes that keep us going. How the body is making use of glucose is an important indicator of health, so researchers are interested in tracking this progress. However, current tools for observing glucose’s journey are limited to the first steps of its metabolism, meaning it’s hard to see what happens next. A new technique called STRIDE can image the full picture of glucose uptake and metabolism, even after it is broken down into component parts and being used by cells after six days (seen here in blue, permeated through a slice of mouse tissue). Imaging glucose metabolism could ultimately help give a clear view of how diseased organs are behaving, and help develop our understanding of the way cancers power their deadly development.


Written by Anthony Lewis



You can also follow BPoD on Instagram, Twitter and Facebook


Archive link


2019 July 4 In the Shadow of the Moon Image Credit &…


2019 July 4


In the Shadow of the Moon
Image Credit & Copyright: Yuri Beletsky (Carnegie Las Campanas Observatory, TWAN)


Explanation: On July 2 denizens of planet Earth could stand in the Moon’s dark umbral shadow during South America’s 2019 total solar eclipse. It first touched down in the Southern Pacific Ocean, east of New Zealand. Racing toward the east along a narrow track, the shadow of the Moon made landfall along the Chilean coast with the Sun low on the western horizon. Captured in the foreground here are long shadows still cast by direct sunlight though, in the final moments before totality began. While diffraction spikes are from the camera lens aperture, the almost totally eclipsed Sun briefly shone like a beautiful diamond ring in the clear, darkened sky.


∞ Source: apod.nasa.gov/apod/ap190704.html


ancientpeopleancientplaces: v. lasting marks poemWritten by The…


ancientpeopleancientplaces:



v. lasting marks poem


Written by The Silicon Tribesman. All rights reserved, 2019.



Source link


Spiraling Filaments Feed Young Galaxies


Artist’s impression of a growing galaxy shows gas spiraling in toward the center. new observations from the keck cosmic web imager provide the best evidence yet that cold gas spirals directly into growing galaxies via filamentous structures. much of the gas ends up being converted into stars. Image credit: Adam Makarenko/W. M. Keck Observatory


New data from W. M. Keck Observatory show gas directly spiraling into growing galaxies 


Maunakea, Hawaii – Galaxies grow by accumulating gas from their surroundings and converting it to stars, but the details of this process have remained murky. New observations, made using the Keck Cosmic Web Imager (KCWI) at W. M. Keck Observatory in Hawaii, now provide the clearest, most direct evidence yet that filaments of cool gas spiral into young galaxies, supplying the fuel for stars.

“For the first time, we are seeing filaments of gas directly spiral into a galaxy. It’s like a pipeline going straight in,” says Christopher Martin, a professor of physics at Caltech and lead author of a new paper appearing in the July 1 issue of the journal Nature Astronomy. “This pipeline of gas sustains star formation, explaining how galaxies can make stars on very fast timescales.”


For years, astronomers have debated exactly how gas makes its way to the center of galaxies. Does it heat up dramatically as it collides with the surrounding hot gas? Or does it stream in along thin dense filaments, remaining relatively cold? 


“Modern theory suggests that the answer is probably a mix of both, but proving the existence of these cold streams of gas had remained a major challenge until now,” says co-author Donal O’Sullivan (MS ’15), a PhD student in Martin’s group who built part of KCWI.


KCWI, designed and built at Caltech, is a state-of-the-art spectral imaging camera. Called an integral-field unit spectrograph, it allows astronomers to take images such that every pixel in the image contains a dispersed spectrum of light. Installed at Keck Observatory in early 2017, KCWI is the successor to the Cosmic Web Imager (CWI), an instrument that has operated at Palomar Observatory near San Diego since 2010. KCWI has eight times the spatial resolution and 10 times the sensitivity of CWI. 


“The main driver for building KCWI was understanding and characterizing the cosmic web, but the instrument is very flexible, and scientists have used it, among other things, to study the nature of dark matter, to investigate black holes, and to refine our understanding of star formation,” says co-author Mateusz (Matt) Matuszewski (MS ’02, PhD ’12), a senior instrument scientist at Caltech.


The question of how galaxies and stars form out of a network of wispy filaments in space—what is known as the cosmic web—has fascinated Martin since he was a graduate student. To find answers, he led the teams that built both CWI and KCWI. In 2017, Martin and his team used KCWI to acquire data on two active galaxies known as quasars, named UM 287 and CSO 38, but it was not the quasars themselves they wanted to study.


Nearby each of these two quasars is a giant nebula, larger than the Milky Way and visible thanks to the strong illumination of the quasars. By looking at light emitted by hydrogen in the nebulas—specifically an atomic emission line called hydrogen Lyman-alpha—they were able to map the velocity of the gas. From previous observations at Palomar, the team already knew there were signs of rotation in the nebulas, but the Keck Observatory data revealed much more.


“When we used Palomar’s CWI previously, we were able to see what looked like a rotating disk of gas, but we couldn’t make out any filaments,” says O’Sullivan. “Now, with the increase in sensitivity and resolution with KCWI, we have more sophisticated models and can see that these objects are being fed by gas flowing in from attached filaments, which is strong evidence that the cosmic web is connected to and fueling this disk.”


Martin and colleagues developed a mathematical model to explain the velocities they were seeing in the gas and tested it on UM287 and CSO38 as well as on a simulated galaxy.


“It took us more than a year to come up with the mathematical model to explain the radial flow of the gas,” says Martin. “Once we did, we were shocked by how well the model works.”


The findings provide the best evidence to date for the cold-flow model of galaxy formation, which basically states that cool gas can flow directly into forming galaxies, where it is converted into stars. Before this model came into popularity, researchers had proposed that galaxies pull in gas and heat it up to extremely high temperatures. From there, the gas was thought to gradually cool, providing a steady but slow supply of fuel for stars.


In 1996, research from Caltech’s Charles (Chuck) Steidel, the Lee A. DuBridge Professor of Astronomy and a co-author of the new study, threw this model into question. He and his colleagues showed that distant galaxies produce stars at a very high rate—too fast to be accounted for by the slow settling and cooling of hot gas that was a favored model for young galaxy fueling.


“Through the years, we’ve acquired more and more evidence for the cold-flow model,” says Martin. “We have nicknamed our new version of the model the ‘cold-flow inspiral,’ since we see the spiraling pattern in the gas.”


“These type of measurements are exactly the kind of science we want to do with KCWI,” says John O’Meara, Keck Observatory chief scientist. “We combine the power of Keck’s telescope size, powerful instrumentation, and an amazing astronomical site to push the boundaries of what’s possible to observe. It’s very exciting to see this result in particular, since directly observing inflows has been something of a missing link in our ability to test models of galaxy formation and evolution. I can’t wait to see what’s coming next.”


The new study, titled, “Multi-Filament Inflows Fuel Young Star Forming Galaxies,” was funded by the National Science Foundation (NSF), Keck Observatory, Caltech, and the European Research Council. The galaxy simulations were performed at NASA Advanced Supercomputing at NASA Ames Research Center. Other Caltech authors include former postdoc Erika Hamden, now at the University of Arizona; Patrick Morrissey, a visitor in space astrophysics who also works at JPL, which is managed by Caltech for NASA; and research scientist James D. (Don) Neill.





About KCWI

The Keck Cosmic Web Imager (KCWI) is designed to provide visible band, integral field spectroscopy with moderate to high spectral resolution formats and excellent sky-subtraction. The astronomical seeing and large aperture of the telescope will enable studies of the connection between galaxies and the gas in their dark matter halos, stellar relics, star clusters, and lensed galaxies. Support for this project was provided by Caltech, Gordon and Betty Moore Foundation, the Heising-Simons Foundation, Mt. Cuba Astronomical Foundation, NSF, and other Friends of Keck Observatory.



About W.M.Keck Observatory

The W. M. Keck Observatory telescopes are the most scientifically productive on Earth. The two, 10-meter optical/infrared telescopes atop Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors recognize and acknowledge the very significant cultural role that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.



Archive link


NASA’s First Rover on the Red Planet


NASA — Mars Pathfinder Mission patch.


July 3, 2019



This 8-image mosaic is of Sojourner, NASA’s first rover on Mars, and was acquired during the late afternoon on Sol 2, the second Martian day on the planet as part of an «insurance panorama.» Sojourner arrived aboard the Mars Pathfinder on July 4, 1997.


This color image was designed as «insurance» against camera failure upon deployment. However, the camera deployment was successful, leaving the insurance panorama to be downlinked to Earth several weeks later. Ironically enough, the insurance panorama contains some of the best quality image data because of the lossless data compression and relatively dust-free state of the camera and associated lander/rover hardware on Sol 2.


Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998.


Right now, NASA is taking steps to begin a new era of exploration. Working with U.S. companies and international partners, NASA will push the boundaries of human exploration forward to the Moon and on to Mars, establishing a permanent human presence on the Moon within the next decade.


Mars Pathfinder and Sojourner: http://www.nasa.gov/mission_pages/mars-pathfinder/


Image, Text, Credits: NASA/Yvette Smith/JPL.


Greetings, Orbiter.chArchive link


Crew Explores Space Biology, Radiation Exposure Before Independence Day


ISS — Expedition 60 Mission patch.


July 3, 2019


The Expedition 60 crew explored space biology and radiation exposure aboard the International Space Station today. The orbital residents also filmed a virtual reality experience and oversaw the deployment of a set microsatellites.


NASA astronaut Christina Koch tended plants and stored microalgae samples for a pair of biology studies investigating ways to support long-term missions farther away from Earth. The two-part VEG-04 study is researching space agriculture as a method to nourish future crews as NASA prepares to go to the Moon and beyond. Microalgae is being observed for the Photobioreactor experiment that aims to demonstrate a hybrid life support system.



Image above: Expedition 60 Flight Engineer Christina Koch of NASA playfully demonstrates how fluids behave in the weightless environment of microgravity aboard the International Space Station. Image Credit: NASA.


A series of seven CubeSats were deployed outside Japan’s Kibo laboratory module today. NASA Flight Engineer Nick Hague configured the seven microsatellites last week and installed them in a Kibo’s small satellite deployer. An international team of engineers and students designed the CubeSats for a variety of experiments and technology demonstrations.


Both astronauts teamed up in the afternoon for another filming session depicting life aboard the orbital outpost. The crew has been videotaping a cinematic, virtual reality experience on the station to share with audiences on Earth.



International Space Station (ISS). Animation Credit: NASA

Commander Alexey Ovchinin set up radiation detectors throughout the station’s Russian segment this morning. The Matroyshka experiment is observing the amount of radiation the station and the crew are exposed to on its flight path.


The orbiting trio will take a day off on July 4 and relax aboard the station. Back on Earth, a new set of Expedition 60 crewmates will fly from Russia on the U.S. Independence Day to their launch site at the Baikonur Cosmodrome in Kazakhstan. Astronauts Andrew Morgan and Luca Parmitano are in final preparations with cosmonaut Alexander Skvortsov for a July 20 liftoff to their new home in space. Their launch comes 50 years to the day NASA landed humans on the Moon for the first time.


Related links:


Expedition 60: https://www.nasa.gov/mission_pages/station/expeditions/expedition60/index.html


VEG-04: https://go.nasa.gov/2LwdoeG


Photobioreactor: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7426


Kibo laboratory module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory


Matroyshka: https://go.nasa.gov/2GcuT1J


Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.


Best regards, Orbiter.chArchive link


Featured

Полет на параплане с обрыва на мысу Куяльницкого лимана, соленого озера. Экстремальный развлекательный полет проводится для любителей. ...

Popular