Metzger, B. D., Margalit, B. & Sironi, L. Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves. Mon. Not. R. Astron. Soc. 485, 4091–4106 (2019).
Cordes, J. M. & Lazio, T. J. W. NE2001. I. A new model for the galactic distribution of free electrons and its fluctuations. Preprint at https://arxiv.org/abs/astro-ph/0207156 (2002).
16.
Yao, J. M., Manchester, R. N. & Wang, N. A new electron-density model for estimation of pulsar and FRB distances. Astrophys. J. 835, 29 (2017).
Kothes, R., Sun, X., Gaensler, B. & Reich, W. A radio continuum and polarization study of SNR G57.2+0.8 associated with magnetar SGR 1935+2154. Astrophys. J. 852, 54 (2018).
Zhou, P. et al. Revisiting the distance, environment and supernova properties of SNR G57.2+0.8 that hosts SGR 1935+2154. Preprint at https://arxiv.org/abs/2005.03517 (2020).
22.
Mereghetti, S. et al. INTEGRAL IBIS and SPI-ACS detection of a hard X-ray counterpart of the radio burst from SGR 1935+2154. Astron. Telegr. 13685 (2020).
23.
Ridnaia, A. et al. Konus-Wind observation of hard X-ray counterpart of the radio burst from SGR 1935+2154. Astron. Telegr. 13688 (2020).
24.
Zhang, S. N. et al. Insight-HXMT X-ray and hard X-ray detection of the double peaks of the fast radio burst from SGR 1935+2154. Astron. Telegr. 13696 (2020).
25.
Zhang, S. N. et al. Geocentric time correction for Insight-HXMT detection of the X-ray counterpart of the FRB by CHIME and STARE2 from SGR 1935+2154. Astron. Telegr. 13704 (2020).
26.
Tendulkar, S. P., Kaspi, V. M. & Patel, C. Radio nondetection of the SGR 1806–20 giant flare and implications for fast radio bursts. Astrophys. J. 827, 59 (2016).
von Kienlin, A. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs. GCN Circ. 26163 (2019).
29.
Ambrosi, E., D’Elia, V., Kennea, J. A. & Palmer, D. Trigger 933276: Swift detection of further activity from SGR 1935+2154. GCN Circ. 26169 (2019).
30.
Palmer, D. Trigger 933285: Swift detection of the brightest burst so far from SGR 1935+2154. GCN Circ. 26171 (2019).
31.
Pearlman, A. B., Majid, W. A., Prince, T. A., Kocz, J. & Horiuchi, S. Pulse morphology of the Galactic Center magnetar PSR J1745–2900. Astrophys. J. 866, 160 (2018).
Burgay, M. et al. Search for FRB and FRB-like single pulses in Parkes magnetar data. In Pulsar Astrophysics: the Next Fifty Years (eds Weltevrede, P. et al.) 319–321 (2018).
34.
Bera, A. & Chengalur, J. N. Super-giant pulses from the Crab pulsar: energy distribution and occurrence rate. Mon. Not. R. Astron. Soc. 490, L12–L16 (2019).
Pol, N., Lam, M. T., McLaughlin, M. A., Lazio, T. J. W. & Cordes, J. M. Estimates of fast radio burst dispersion measures from cosmological simulations. Astrophys. J. 886, 135 (2019).
Kumar, P., Lu, W. & Bhattacharya, M. Fast radio burst source properties and curvature radiation model. Mon. Not. R. Astron. Soc. 468, 2726–2739 (2017).
Bhandari, S. et al. The Survey for Pulsars and Extragalactic Radio Bursts—II. New FRB discoveries and their follow-up. Mon. Not. R. Astron. Soc. 475, 1427–1446 (2018).
Gajjar, V. et al. Highest frequency detection of FRB 121102 at 4–8 GHz using the Breakthrough Listen digital backend at the Green Bank Telescope. Astrophys. J. 863, 2 (2018).
Ng, C. et al. CHIME FRB: an application of FFT beamforming for a radio telescope. In Proc. XXXII General Assembly and Scientific Symp. Intl Union of Radio Science (URSI GASS) J33-2 (2017).
52.
Masui, K. W. et al. Algorithms for FFT beamforming radio interferometers. Astrophys. J. 879, 16 (2019).
Berger, P. et al. Holographic beam mapping of the CHIME pathfinder array. In Ground-based and Airborne Telescopes VI (eds Hall, H. J., Gilmozzi, R. & Marshall, H. K.) 99060D (SPIE, 2016).
56.
Bandura, K. et al. Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder. In Ground-based and Airborne Telescopes V (eds Stepp, L. M., Gilmozzi, R. & Hall, H. J.) 914522 (SPIE, 2014).
57.
Bandura, K. et al. ICE: a scalable, low-cost FPGA-based telescope signal processing and networking system. J. Astron. Instrum. 5, 1641005 (2016).
Sobey, C. et al. Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3D Galactic halo magnetic field. Mon. Not. R. Astron. Soc. 484, 3646–3664 (2019).
Ester, M., Kriegel, H.-P., Sander, J. & Xu, X. A density-based algorithm for discovering clusters in large spatial databases with noise. In Proc. Second Intl Conf. Knowledge Discovery and Data Mining, KDD’96 (eds Simoudis, E., Han, J. & Fayyad, U.) 226–231 (AAAI, 1996).
62.
Arnaud, K. A. Xspec: the first ten years. In Astronomical Data Analysis Software and Systems V (eds Jacoby, G. & Barnes, J.) 17 (ASP, 1996).
63.
Karachentsev, I. D. & Kaisina, E. I. Star formation properties in the local volume galaxies via Hα and far-ultraviolet fluxes. Astron. J. 146, 46 (2013).
NASA’s Voyager 1 spacecraft is depicted in this artist’s concept traveling through interstellar space, or the space between stars, which it entered in 2012. Credit: NASA/JPL-Caltech
For the first time since November, NASA’s Voyager 1 spacecraft is returning usable data about the health and status of its onboard engineering systems. The next step is to enable the spacecraft to begin returning science data again. The probe and its twin, Voyager 2, are the only spacecraft to ever fly in interstellar space (the space between stars).
Voyager 1 stopped sending readable science and engineering data back to Earth on Nov. 14, 2023, even though mission controllers could tell the spacecraft was still receiving their commands and otherwise operating normally. In March, the Voyager engineering team at NASA’s Jet Propulsion Laboratory in Southern California confirmed that the issue was tied to one of the spacecraft’s three onboard computers, called the flight data subsystem (FDS). The FDS is responsible for packaging the science and engineering data before it’s sent to Earth.
The team discovered that a single chip responsible for storing a portion of the FDS memory—including some of the FDS computer’s software code—isn’t working. The loss of that code rendered the science and engineering data unusable. Unable to repair the chip, the team decided to place the affected code elsewhere in the FDS memory. But no single location is large enough to hold the section of code in its entirety.
So they devised a plan to divide affected the code into sections and store those sections in different places in the FDS. To make this plan work, they also needed to adjust those code sections to ensure, for example, that they all still function as a whole. Any references to the location of that code in other parts of the FDS memory needed to be updated as well.
After receiving data about the health and status of Voyager 1 for the first time in five months, members of the Voyager flight team celebrate in a conference room at NASA’s Jet Propulsion Laboratory on April 20. Credit: NASA/JPL-Caltech
The team started by singling out the code responsible for packaging the spacecraft’s engineering data. They sent it to its new location in the FDS memory on April 18. A radio signal takes about 22.5 hours to reach Voyager 1, which is over 15 billion miles (24 billion kilometers) from Earth, and another 22.5 hours for a signal to come back to Earth. When the mission flight team heard back from the spacecraft on April 20, they saw that the modification had worked: For the first time in five months, they have been able to check the health and status of the spacecraft.
During the coming weeks, the team will relocate and adjust the other affected portions of the FDS software. These include the portions that will start returning science data.
Voyager 2 continues to operate normally. Launched over 46 years ago, the twin Voyager spacecraft are the longest-running and most distant spacecraft in history. Before the start of their interstellar exploration, both probes flew by Saturn and Jupiter, and Voyager 2 flew by Uranus and Neptune.
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Osoyoos commuters can celebrate Earth Day as the Town joins in on a national commuter challenge known as “Leg Day,” entering a chance to win sustainable transportation prizes.
The challenge, from Earth Day Canada, is to record 10 sustainable commutes taken without a car.
“Cars are one of the biggest contributors to gas emissions in Canada,” reads an Earth Day Canada statement. “That’s why, Earth Day Canada is launching the national Earth Day is Leg Day Challenge.”
So far, over 42.000 people have participated in the Leg Day challenge.
Participants could win an iGo electric bike, public transportation for a year, or a gym membership.
The Town of Osoyoos put out a message Monday promoting joining the national program.
For more information on the Leg Day challenge click here.
Verticillium wilt is a problem for a lot of crops in Manitoba, including canola, sunflowers and alfalfa.
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In potatoes, the fungus Verticillium dahlia is the main cause of potato early die complex. In a 2021 interview with the Co-operator, Mario Tenuta, University of Manitoba soil scientist and main investigator with the Canadian Potato Early Dying Network, suggested the condition can cause yield loss of five to 20 per cent. Other research from the U.S. puts that number as high as 50 per cent.
It also becomes a marketing issue when stunted spuds fall short of processor preferences.
Verticillium in potatoes can significantly reduce yield and, being soil-borne, is difficult to manage.
Preliminary research results suggest earlier planting of risk-prone fields could reduce losses, in part due to colder soil temperatures earlier in the season.
Unlike other potato fungal issues that can be addressed with foliar fungicide, verticillium hides in the soil.
“Commonly we use soil fumigation and that’s very expensive,” said Julie Pasche, plant pathologist with North Dakota State University.
There are options. In 2017, labels expanded for the fungicide Aprovia, Syngenta’s broad-spectrum answer for leaf spots or powdery mildews in various horticulture crops. In-furrow verticillium suppression for potatoes was added to the label.
There has also been interest in biofumigation. Mustard has been tagged as a potential companion crop for potatoes, thanks to its production of glucosinolate and the pathogen- and pest-inhibiting substance isothiocyanate.
Last fall, producers heard that a new, sterile mustard variety specifically designed for biofumigation had been cleared for sale in Canada, although seed supplies for 2024 are expected to be slim. AAC Guard was specifically noted for its effectiveness against verticillium wilt.
Timing is everything
Researchers at NDSU want to study the advantage of natural plant growth patterns.
“What we’d like to look at are other things we can do differently, like verticillium fertility management and water management, as well as some other areas and how they may be affected by planting date,” Pasche said.
The idea is to find a chink in the fungus’s life cycle.
Verticillium infects roots in the spring. From there, it colonizes the plant, moving through the root vascular tissue and into the stem. This is the cause of in-season vegetative wilting, Pasche noted.
As it progresses, plant cells die, leaving behind tell-tale black dots on dead tissue. Magnification of those dots reveals what look like dark bunches of grapes — tiny spheres containing melanized hyphae, a resting form of the fungus called microsclerotia.
The dark colour comes from melanin, the same pigment found in human skin. This pigmentation protects the microsclerotia from ultraviolet light.
