scholarly journals COMMISSIONING OF THE RT-32 RADIO TELESCOPE: NEW OPPORTUNITIES FOR DOMESTIC RADIO ASTRONOMY AND SPACE NAVIGATION Transcript of scientific report at the meeting of the Presidium of NAS of Ukraine, November 27, 2020

2020 ◽  
pp. 69-75
Author(s):  
Vyacheslav V. Zakharenko ◽  
Keyword(s):  
Radio Telescope ◽  
Radio Astronomy ◽  
Scientific Cooperation ◽  
Simultaneous Observation ◽  
Space Navigation ◽  
Main Work ◽  
Highly Sensitive ◽  
Scientific Report ◽  
International Scientific Cooperation

In November 2020, the main work on the commissioning of the centimeter range radio telescope RT-32, equipped with highly sensitive receiving equipment, which allows simultaneous observation in the range of 6; 3 and 1.35 cm, was completed. This opens wide opportunities for international scientific cooperation in the field of radio astronomy and the return of Ukraine to the world's largest radio interferometric network with ultra-long bases, the European VLBI Network.

scholarly journals An in-depth investigation of 11 pulsars discovered by FAST

2020 ◽  
Vol 495 (3) ◽  
pp. 3515-3530 ◽  
Author(s):  
A D Cameron ◽  
D Li ◽  
G Hobbs ◽  
L Zhang ◽  
C C Miao ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Radio Astronomy ◽  
Lessons Learned ◽  
Polarization Angle ◽  
Next Generation ◽  
Highly Sensitive ◽  
Linearly Polarized ◽  
Drift Scan ◽  
One Year ◽  
The Way

ABSTRACT We present timing solutions and analyses of 11 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These pulsars were discovered using an ultrawide bandwidth receiver in drift-scan observations made during the commissioning phase of FAST, and were then confirmed and timed using the 64-m Parkes Radio Telescope. Each pulsar has been observed over a span of at least one year. Highlighted discoveries include PSR J0344−0901, which displays mode-changing behaviour and may belong to the class of so-called swooshing pulsars (alongside PSRs B0919+06 and B1859+07); PSR J0803−0942, whose emission is almost completely linearly polarized; and PSRs J1900−0134 and J1945+1211, whose well-defined polarization angle curves place stringent constraints on their emission geometry. We further discuss the detectability of these pulsars by earlier surveys, and highlight lessons learned from our work in carrying out confirmation and monitoring observations of pulsars discovered by a highly sensitive telescope, many of which may be applicable to next-generation pulsar surveys. This paper marks one of the first major releases of FAST-discovered pulsars, and paves the way for future discoveries anticipated from the Commensal Radio Astronomy FAST Survey.

scholarly journals RFI Survey for the Giant Metrewave Radio Telescope in India

1991 ◽  
Vol 112 ◽  
pp. 190-193
Author(s):  
G. Swarup ◽  
T.L. Venkatasubramani
Keyword(s):  
Radio Frequency ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Radio Frequency Interference ◽  
Frequency Range ◽  
Extragalactic Astronomy ◽  
Low Level ◽  
Highly Sensitive ◽  
Set Up

ABSTRACTA Giant Meterwave Radio Telescope (GMRT) is being set up at Khodad about 80 km north of Pune in India for operation in the frequency range of about 30 to 1500 MHz. It is to be completed by 1992 and is being designed to investigate many outstanding problems in the fields of galactic and extragalactic astronomy. We present here measurements of man-made radio frequency interference (RFI) conducted at the GMRT site in 1985 and 1988. It is seen that highly sensitive radio astronomy observations can still be made at selected bands in the above frequency range because of the relatively low level of RFI in India. However, this advantage may not remain for more than a decade or two.

scholarly journals A distinct negative leader propagation mode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
O. Scholten ◽  
B. M. Hare ◽  
J. Dwyer ◽  
N. Liu ◽  
C. Sterpka ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Electric Discharge ◽  
Radio Astronomy ◽  
Propagation Mode ◽  
Common Phenomenon ◽  
High Charge ◽  
Initial Stage ◽  
Lightning Initiation ◽  
The Common

AbstractThe common phenomenon of lightning still harbors many secrets such as what are the conditions for lightning initiation and what is driving the discharge to propagate over several tens of kilometers through the atmosphere forming conducting ionized channels called leaders. Since lightning is an electric discharge phenomenon, there are positively and negatively charged leaders. In this work we report on measurements made with the LOFAR radio telescope, an instrument primarily build for radio-astronomy observations. It is observed that a negative leader rather suddenly changes, for a few milliseconds, into a mode where it radiates 100 times more VHF power than typical negative leaders after which it spawns a large number of more typical negative leaders. This mode occurs during the initial stage, soon after initiation, of all lightning flashes we have mapped (about 25). For some flashes this mode occurs also well after initiation and we show one case where it is triggered twice, some 100 ms apart. We postulate that this is indicative of a small (order of 5 km$$^2$$ 2 ) high charge pocket. Lightning thus appears to be initiated exclusively in the vicinity of such a small but dense charge pocket.

scholarly journals Smallpox eradication, laboratory visits, and a touch of tourism: travel notes of a Canadian scientist in Brazil

2010 ◽  
Vol 17 (3) ◽  
pp. 777-790 ◽  
Author(s):  
Steven Palmer ◽  
Gilberto Hochman ◽  
Danieli Arbex
Keyword(s):  
World Health Organisation ◽  
Scientific Activity ◽  
World Health ◽  
Eradication Programme ◽  
Scientific Cooperation ◽  
The World ◽  
Eradication Campaign ◽  
The 1960S ◽  
International Scientific Cooperation

The paper presents and discusses the travel notes diary of Canadian scientist Robert J. Wilson when he visited Brazil in April 1967 during the Smallpox Eradication Programme run by the World Health Organisation. Wilson's report makes it possible to reflect on the smallpox eradication campaign in Brazil; on the Canada-Brazil cooperation to improve the quality of the smallpox vaccine; on his assessment by of scientists and Brazilian laboratories; on the effects of intersections between scientific activity and social and cultural activities; on the role played by specialist communities of experts role in international scientific cooperation projects; and on a Canadian traveller's concepts and prejudices about Brazil at the end of the 1960s.

scholarly journals INTERSTELLAR MEDIUM AND DECAMETER RADIO SPECTROSCOPY

2021 ◽  
Vol 26 (4) ◽  
pp. 314-325
Author(s):  
S. V. Stepkin ◽  
◽  
O. O. Konovalenko ◽  
Y. V. Vasylkivskyi ◽  
D. V. Mukha ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Low Frequency ◽  
Spectral Lines ◽  
Physical Parameters ◽  
Recombination Mechanism ◽  
Radio Recombination Lines ◽  
Radio Spectroscopy ◽  
Correlation Spectrum

Purpose: The analytical review of the main results of research in the new direction of the low-frequency radio astronomy, the interstellar medium radio spectroscopy at decameter waves, which had led to astrophysical discovery, recording of the radio recombination lines in absorption for highly excited states of interstellar carbon atoms (more than 600). Design/methodology/approach: The UTR-2 world-largest broadband radio telescope of decameter waves optimally connected with the digital correlation spectrum analyzers has been used. Continuous modernization of antenna system and devices allowed increasing the analysis band from 100 kHzto 24 MHz and a number of channels from 32 to 8192. The radio telescope and receiving equipment with appropriate software allowed to have a long efficient integration time enough for a large line series simultaneously with high resolution, noise immunity and relative sensitivity. Findings: A new type of interstellar spectral lines has been discovered and studied, the interstellar carbon radio recombination lines in absorption for the record high excited atoms with principal quantum numbers greater than 1000. The line parameters (intensity, shape, width, radial velocity) and their relation ship with the interstellar medium physical parameters have been determined. The temperature of line forming regions is about 100 K, the electron concentration up to 0.1 cm–3 and the size of a line forming region is about 10 pc. For the first time, radio recombination lines were observed in absorption. They have significant broadening and are amplified by the dielectronic-like recombination mechanism and are also the lowest frequency lines in atomic spectroscopy. Conclusions: The detected low-frequency carbon radio recombination lines and their observations have become a new highly effective tool for the cold partially ionized interstellar plasma diagnostics. Using them allows obtaining the information which is not available with the other astrophysical methods. For almost half a century of their research, a large amount of hardware-methodical and astrophysical results have been obtained including a record number of Galaxy objects, where there levant lines have been recorded. The domestic achievements have stimulated many theoretical and experimental studies in other countries, but the scientific achievements of Ukrainian scientists prove the best prospects for further development of this very important area of astronomical science. Key words: low-frequency radio astronomy; radio telescope; interstellar medium; radio recombination lines; carbon; hydrogen; spectral analyzer

scholarly journals Status of the Thai 40-m Radio Telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 346-347
Author(s):  
Phrudth Jaroenjittichai
Keyword(s):  
Radio Telescope ◽  
Radio Astronomy ◽  
Time Domain ◽  
Phased Array ◽  
Low Frequency ◽  
Great Leap ◽  
Great Leap Forward ◽  
Astronomical Research ◽  
L Band ◽  
K Band

AbstractSince the first light of the 2.4-m Thai National Telescope in 2013, Thailand foresees another great leap forward in astronomy. A project known as “Radio Astronomy Network and Geodesy for Development” (RANGD) by National Astronomical Research Institute of Thailand (NARIT) has been approved for year 2017-2021. A 40-m radio telescope has been planned to operate up to 115-GHz observation with prime-focus capability for low frequency and phased array feed receivers. The telescope’s first light is expected in late 2019 with a cryogenics K-band and L-band receivers. RFI environment at the site has been investigated and shown to be at reasonable level. A 13-m VGOS telescope is also included for geodetic applications. Early single-dish science will focus on time domain observations, such as pulsars and transients, outbursts and variability of maser and AGN sources.

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