scholarly journals A 10-GHZ Radio Continuum Survey of the Galactic Plane

1987 ◽  
Vol 115 ◽  
pp. 538-539
Author(s):  
T. Handa ◽  
Y. Sofue ◽  
N. Nakai ◽  
H. Hirabayashi ◽  
K. Akabane ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Noise Temperature ◽  
Radio Continuum ◽  
Beam Size ◽  
Calibration Source ◽  
Polarization Component ◽  
Radio Observatory ◽  
System Noise ◽  
Ngc 7027 ◽  
5 Ghz

A radio continuum survey of the galactic plane has been made with the 45-m telescope of the Nobeyama Radio Observatory at 10.55 GHz, which is the highest frequency among such surveys. The sensitivity of the telescope was Tb/S = 0.47 K/Jy and the HPBW was 2!6, which was a great advantage because of the same beam size of the Bonn 5-GHz survey (Altenhoff et al. 1978). The receiver was a cooled parametric amplifier. The instantaneous bandwidth was 500 MHz, and the system noise temperature was about 100 K. The calibration source was NGC 7027, which was assumed to be 6.6 Jy. One circular polarization component was observed. The observational parameters are summarized in Table I.

scholarly journals The Sgr B2 Region Seen at 43 GHZ

1987 ◽  
Vol 115 ◽  
pp. 158-160
Author(s):  
Hisashi Hirabayashi ◽  
Kenji Akabane ◽  
Masaki Morimoto ◽  
Yosiaki Sofue ◽  
Makato Inoue ◽  
...  
Keyword(s):  
Flux Density ◽  
Noise Temperature ◽  
Central Frequency ◽  
Radio Observatory ◽  
System Noise ◽  
Ngc 7027 ◽  
Pointing Accuracy ◽  
Half Power ◽  
5 Ghz ◽  
Better Than

The Sgr B2 region was mapped at 43 GHz (λ = 6.9 mm) with the 45m radio telescope of Nobeyama Radio Observatory. The observing parameters were: a) half power beamwidth 38″, b) pointing accuracy better than 10″, c) central frequency 43.0 GHz, d) bandwidth 500 MHz, and e) system noise temperature 400 K; and the observational aspects were: a) mapping with one polarization, b) liquid-nitrogen cooled load switching and c) reduction by NOD-2 programme. The obtained map is shown in Figure 1. Sgr B2 is resolved into several components which correspond to those by Martin and Downes (1972) and Downes et al. (1978). But the component at RA = 17h44m11.8s Dec. = −28°23′55″ at 1950 is not seen in Martin and Downes (1972) nor in the 5 GHz map of Downes et al. (1978), although the feature is seen in the 10.7 GHz map of Downes et al. (1978). The components derived from the map in Figure 1 by a morphological estimate are listed in Table 1. The total flux density of the region is 146J±30 Jy. The intensity calibration was made by observing NGC 7027.

scholarly journals CORNISH: A 5 GHz VLA survey of the Galactic plane

2009 ◽  
Vol 5 (H15) ◽  
pp. 781-781
Author(s):  
Cormac R. Purcell ◽  
Melvin G. Hoare ◽  
Keyword(s):  
Star Formation ◽  
Galactic Plane ◽  
Radio Continuum ◽  
High Mass ◽  
Mass Star ◽  
Multi Wavelength ◽  
Region 10 ◽  
5 Ghz ◽  
Infrared Survey ◽  
Key Questions

AbstractThe CORNISH (Co-Ordinated Radio ‘N’ Infrared Survey for High-mass star formation) project is the radio continuum part of a series of multi-wavelength surveys of the Galactic Plane that focus on the northern GLIMPSE-I region (10° < l <65°, |b| < 1°) observed by the SPITZER satellite in the mid-infrared (Churchwell et al. 2009). CORNISH has delivered a complementary 5 GHz arcsecond resolution, radio-continuum survey to address key questions in high-mass star formation as well as many other areas of astrophysics.

scholarly journals A 10-Ghz radio-continuum survey of the Galactic–plane region at the Nobeyama Radio Observatory - A complex region at ℓ = 22° − 25°

1985 ◽  
Vol 106 ◽  
pp. 323-324
Author(s):  
Y. Sofue ◽  
H. Hirabayashi ◽  
K. Akabane ◽  
M. Inoue ◽  
T. Handa ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Extensive Study ◽  
Radio Continuum ◽  
Plane Region ◽  
Radio Observatory ◽  
Complex Region ◽  
Preliminary Results

Preliminary results of a 10-GHz radio-continuum survey of the galactic-plane region using the 45-m telescope at NRO are presented. An extensive study of a complex region at 22° ≦ ℓ ≦ 25°, |b|≳1° has been made.

Deep Survey of the Radio Continuum Emission along the Southern Galactic Plane at 2·4 GHz

1995 ◽  
Vol 12 (1) ◽  
pp. 54-59 ◽  
Author(s):  
A. R. Duncan ◽  
R. T. Stewart ◽  
R. F. Haynes ◽  
K. L. Jones
Keyword(s):  
Large Scale ◽  
Galactic Plane ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Total Power ◽  
Latitude Range ◽  
Power Maps ◽  
Deep Survey ◽  
5 Ghz ◽  
Linear Polarisation

AbstractWe have just completed the observational stage of a 2·4 GHz survey of the Southern Galactic Plane, using the Parkes radiotelescope, between 238° ≤ l ≤ 365° and with a latitude range of at least |b| ≤ 5° (beamwidth ~9 arcmin). The survey details both continuum emission and linear polarisation down to rms noises of approximately 12 and 4 mJy/beam respectively. It is the most sensitive survey to date of the southern plane at this frequency and should nicely complement the Effelsberg northern plane surveys in addition to the recent southern surveys such as the 843 MHz MOST survey and the 5 GHz PMN survey. The total-power maps are now completed, and reduction of the polarisation data is still in progress. In addition to compact HII regions and extragalactic sources, we are detecting on our total-power images a considerable amount of large-scale structure, and a significant number of new SNR candidates and spur-like features.

22 GHz Observations with the Resurfaced Central 17 m of the Parkes Radio Telescope

1976 ◽  
Vol 3 (1) ◽  
pp. 61-63 ◽  
Author(s):  
J. L. Caswell ◽  
R. A. Batchelor ◽  
W. M. Goss ◽  
R. F. Haynes ◽  
S. H. Knowles ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Radio Telescope ◽  
Noise Temperature ◽  
Parametric Amplifier ◽  
Total System ◽  
High Frequencies ◽  
Second Stage ◽  
System Noise ◽  
Front End ◽  
5 Ghz

At the centre of the Parkes 64—m radio telescope a region of diameter 17 m has recently been resurfaced to improve its efficiency at high frequencies. The first measurements using this section have been made at 22 GHz, in observations of both continuum sources and water tfapour masers. For these observations the receiver front-end used a mixer cooled in liquid nitrogen, followed by a 5 GHz cryogenic parametric amplifier as a second stage. The option of switching against an offset horn was available and the total system noise temperature was ∽ 750 K.

Radio continuum of galaxies with H2O megamaser disks

2017 ◽  
Vol 13 (S336) ◽  
pp. 139-140
Author(s):  
F. Kamali ◽  
C. Henkel ◽  
A. Brunthaler ◽  
C. M. V. Impellizzeri ◽  
K. M. Menten ◽  
...  
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Active Galactic Nucleus ◽  
Position Angle ◽  
Radio Continuum ◽  
Supermassive Black Hole ◽  
5 Ghz

AbstractIn our attempt to investigate the basic active galactic nucleus (AGN) paradigm requiring a centrally located supermassive black hole (SMBH), a close to Keplerian accretion disk and a jet perpendicular to its plane, we have searched for radio continuum in galaxies with H2O megamasers in their disks. We observed 18 such galaxies with the Very Large Baseline Array in C band (5 GHz, ~2 mas resolution) and we detected 5 galaxies at 8 σ or higher levels. For those sources for which the maser data is available, the positions of masers and those of the 5 GHz radio continuum sources coincide within the uncertainties, and the radio continuum is perpendicular to the maser disk’s orientation within the position angle uncertainties.

Unified Definitions of Efficiencies and System Noise Temperature for Receiving Antenna Arrays

2010 ◽  
Vol 58 (6) ◽  
pp. 2121-2125 ◽  
Author(s):  
Karl F Warnick ◽  
Marianna V Ivashina ◽  
Rob Maaskant ◽  
Bert Woestenburg
Keyword(s):  
Antenna Arrays ◽  
Noise Temperature ◽  
System Noise ◽  
Receiving Antenna

scholarly journals A Novel Method for Estimating the Ambient Medium Density Around Distant Radio Sources from Their Observed Radio Spectra

2021 ◽  
Vol 922 (2) ◽  
pp. 197
Author(s):  
Anna Wójtowicz ◽  
Łukasz Stawarz ◽  
Jerzy Machalski ◽  
Luisa Ostorero
Keyword(s):  
Radio Emission ◽  
Ambient Medium ◽  
Radio Galaxies ◽  
Radiative Properties ◽  
Radio Continuum ◽  
Physical Parameters ◽  
Radio Sources ◽  
Data Set ◽  
Radio Structure ◽  
5 Ghz

Abstract The dynamical evolution and radiative properties of luminous radio galaxies and quasars of the FR II type, are well understood. As a result, through the use of detailed modeling of the observed radio emission of such sources, one can estimate various physical parameters of the systems, including the density of the ambient medium into which the radio structure evolves. This, however, requires rather comprehensive observational information, i.e., sampling the broadband radio continua of the targets at several frequencies, and imaging their radio structures with high resolution. Such observations are, on the other hand, not always available, especially for high-redshift objects. Here, we analyze the best-fit values of the source physical parameters, derived from extensive modeling of the largest currently available sample of FR II radio sources, for which good-quality multiwavelength radio flux measurements could be collected. In the analyzed data set, we notice a significant and nonobvious correlation between the spectral index of the nonthermal radio emission continuum, and density of the ambient medium. We derive the corresponding correlation parameters, and quantify the intrinsic scatter by means of Bayesian analysis. We propose that the discovered correlation could be used as a cosmological tool to estimate the density of ambient medium for large samples of distant radio galaxies. Our method does not require any detailed modeling of individual sources, and relies on limited observational information, namely, the slope of the radio continuum between the rest-frame frequencies 0.4 and 5 GHz, possibly combined with the total linear size of the radio structure.

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