New radio receiver opens wider window to radio universe

Date:
July 8, 2021
Source:
National Institutes of Natural Sciences
Summary:
Researchers have used the latest wireless technology to develop
a new radio receiver for astronomy. The receiver is capable of
capturing radio waves at frequencies over a range several times
wider than conventional ones, and can detect radio waves emitted
by many types of molecules in space at once. This is expected to
enable significant progresses in the study of the evolution of
the Universe and the mechanisms of star and planet formation.



FULL STORY ========================================================================== Researchers have used the latest wireless technology to develop a new
radio receiver for astronomy. The receiver is capable of capturing radio
waves at frequencies over a range several times wider than conventional
ones, and can detect radio waves emitted by many types of molecules in
space at once. This is expected to enable significant progresses in the
study of the evolution of the Universe and the mechanisms of star and
planet formation.


========================================================================== Interstellar molecular clouds of gas and dust provide the material
for stars and planets. Each type of molecule emits radio waves at characteristic frequencies and astronomers have detected emissions from
various molecules over a wide range of frequencies. By observing these
radio waves, we can learn about the physical properties and chemical composition of interstellar molecular clouds. This has been the motivation driving the development of a wideband receiving system.

In general, the range of radio frequencies that can be observed
simultaneously by a radio telescope is very limited. This is due to the characteristics of the components that make up a radio receiver. In this
new research, the team of researchers in Osaka Prefecture University
(OPU) and the National Astronomical Observatory of Japan (NAOJ) has
widened the bandwidth of various components, such as the horn that
brings radio waves into the receiver, the waveguide (metal tube) circuit
that propagates the radio waves, and the radio frequency converter. By combining these components into a receiver system, the team has achieved a range of simultaneously detectable frequencies several times larger than before. Furthermore, this receiver system was mounted on the OPU 1.85-
m radio telescope in NAOJ's Nobeyama Radio Observatory, and succeeded
in capturing radio waves from actual celestial objects. This shows that
the results of this research are extremely useful in actual astronomical observations.

"It was a very emotional moment for me to share the joy of receiving
radio waves from the Orion Nebula for the first time with the members of
the team, using the receiver we had built," comments Yasumasa Yamasaki,
an OPU graduate student and the lead author of the paper describing
the development of the wideband receiver components. "I feel that this achievement was made possible by the cooperation of many people involved
in the project." When compared to the receivers currently used in the
Atacama Large Millimeter/ submillimeter Array (ALMA), the breadth of frequencies that can be simultaneously observed with the new receivers
is striking. To cover the radio frequencies between 211 and 373 GHz,
ALMA uses two receivers, Band 6 and 7, but can use only one of them
at a given time. In addition, ALMA receivers can observe two strips
of frequency ranges with widths of 5.5 and 4 GHz using the Band 6 and
7 receivers, respectively. In contrast, the new wideband receiver can
cover all the frequencies with a single unit. In addition, especially
in the higher frequency band, the receiver can detect radio waves in a frequency range of 17 GHz at a time.

"It was a very valuable experience for me to be involved in the
development of this broadband receiver from the beginning to successful observation," says Sho Masui, a graduate student at OPU and the lead
author of the research paper reporting the development of the receiver
and the test observations. "Based on these experiences, I would like
to continue to devote further efforts to the advancement of astronomy
through instrument development." This wideband technology has made it
possible to observe the interstellar molecular clouds along the Milky
Way more efficiently using the 1.85-m radio telescope. In addition,
widening the receiver bandwidth is listed as one of the high priority
items in the ALMA Development Roadmap which aims to further improve the performance of ALMA. This achievement is expected to be applied to ALMA
and other large radio telescopes, and to make a significant contribution
to enhance our understanding of the evolution of the Universe.

========================================================================== Story Source: Materials provided by
National_Institutes_of_Natural_Sciences. Note: Content may be edited
for style and length.


========================================================================== Journal References:
1. Yasumasa Yamasaki, Sho Masui, Hideo Ogawa, Hiroshi Kondo, Takeru
Matsumoto, Masanari Okawa, Koki Yokoyama, Taisei Minami, Ryotaro
Konishi, Sana Kawashita, Ayu Konishi, Yuka Nakao, Shimpei Nishimoto,
Sho Yoneyama, Shota Ueda, Yutaka Hasegawa, Shinji Fujita, Atsushi
Nishimura, Takafumi Kojima, Keiko Kaneko, Ryo Sakai, Alvaro
Gonzalez, Yoshinori Uzawa, Toshikazu Onishi. Development of a new
wideband heterodyne receiver system for the Osaka 1.85 m
mm-submm telescope: Corrugated horn and optics covering the
210-375 GHz band. Publications of the Astronomical Society
of Japan, 2021; DOI: 10.1093/pasj/psab062
2. Sho Masui, Yasumasa Yamasaki, Hideo Ogawa, Hiroshi Kondo, Koki
Yokoyama,
Takeru Matsumoto, Taisei Minami, Masanari Okawa, Ryotaro Konishi,
Sana Kawashita, Ayu Konishi, Yuka Nakao, Shimpei Nishimoto,
Sho Yoneyama, Shota Ueda, Yutaka Hasegawa, Shinji Fujita,
Atsushi Nishimura, Takafumi Kojima, Kazunori Uemizu, Keiko
Kaneko, Ryo Sakai, Alvaro Gonzalez, Yoshinori Uzawa, Toshikazu
Onishi. Development of a new wideband heterodyne receiver system
for the Osaka 1.85 m mm-submm telescope: Receiver development and
the first light of simultaneous observations in 230 GHz and 345
GHz bands with an SIS-mixer with 4-21&#82. Publications of the
Astronomical Society of Japan, 2021; DOI: 10.1093/pasj/psab046 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/07/210708111502.htm

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