scholarly journals A 610-MHz Galactic Plane Pulsar Search with the Giant Meterwave Radio Telescope

2008 ◽  
Author(s):  
B. C. Joshi ◽  
M. A. McLaughlin ◽  
M. Kramer ◽  
A. G. Lyne ◽  
D. R. Lorimer ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Galactic Plane

scholarly journals A Study of Low density Ionized Gas in the Galactic Plane

2002 ◽  
Vol 199 ◽  
pp. 335-338
Author(s):  
D. Anish Roshi ◽  
K. R. Anantharamaiah
Keyword(s):  
Radio Telescope ◽  
Radial Distribution ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Hii Regions ◽  
Low Density ◽  
Ionized Gas ◽  
Star Forming ◽  
Star Forming Regions ◽  
Complete Survey

A complete survey of radio recombination lines (RRLs) near 327 MHz from the galactic plane (l = 330° − 0°-89°, b = 0°) was carried out using a section of the Ooty Radio Telescope (ORT) with an angular resolution of 2° × 2°. A subset of regions in the same area was observed using the whole telescope which has a beam of 2° × 6'. Hydrogen RRLs were detected in most of the positions that were observed. The lv diagram and radial distribution computed from the observed spectra and their comparison with other species in the galactic plane indicate that the low density gas detected in the survey is distributed similar to the star forming regions. For an assumed temperature of 7000 K, we estimate that the densities and sizes of the regions are in the range 1 — 10 cm−3 and 20 — 200 pc respectively. Our data suggests that the low density ionized gas is in the form of outer envelopes of normal HII regions.

scholarly journals 41. The spherical component of the galactic radio emission

1957 ◽  
Vol 4 ◽  
pp. 233-237
Author(s):  
J. E. Baldwin
Keyword(s):  
Radio Emission ◽  
Brightness Temperature ◽  
Radio Telescope ◽  
Galactic Plane ◽  
Wave Length ◽  
Spherical Component ◽  
Long Wave ◽  
Half Power ◽  
Right Ascension ◽  
Galactic Radio

As part of the programme of observations with the large Cambridge radio telescope, a survey of the integrated radio emission has been made using one of the four elements of the interferometer. At a wave-length of 3·7 metres this aerial has beam-widths to half-power points of 2° in right ascension and 15° in declination. The use of a long wave-length makes it possible to obtain accurate measurements of the brightness temperature of the sky in regions away from the galactic plane. It is with the radiation from these regions that this paper is primarily concerned.

scholarly journals H I Emission and Absorption in the Southern Galactic Plane Survey

2001 ◽  
Vol 18 (1) ◽  
pp. 84-90 ◽  
Author(s):  
N. M. McClure-Griffiths ◽  
John M. Dickey ◽  
B. M. Gaensler ◽  
A. J. Green ◽  
R. F. Haynes ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Radio Telescope ◽  
Large Scale ◽  
Galactic Plane ◽  
Pilot Project ◽  
Small Scale ◽  
Preliminary Results ◽  
Test Region ◽  
Scale Structures ◽  
Spatial Power Spectrum

AbstractWe present preliminary results from the Southern Galactic Plane Survey (SGPS) Test Region and Parkes data. As part of the pilot project for the Southern Galactic Plane Survey, observations of a Test Region (325·5° ≤l ≤ 333·5°; −0·5° ≤ b ≤ 3·5°) were completed in December 1998. Single-dish observations of the full survey region (253° ≤ l ≤ 358 ° |b| ≤ 1°) with the Parkes Radio Telescope were completed in March 2000. We present a sample of SGPS H I data, with particular attention to the smallest-and largest-scale structures seen in absorption and emission, respectively. On the large scale, we detect many prominent H I shells. On the small scale, we note extremely compact, cold clouds seen in H I self-absorption. We explore how these two classes of objects probe opposite ends of the H I spatial power spectrum.

scholarly journals Ammonia towards dust clumps in the giant molecular cloud associated with RCW 106

2012 ◽  
Vol 8 (S292) ◽  
pp. 50-50
Author(s):  
Vicki Lowe ◽  
Maria R. Cunningham ◽  
James S. Urquhart ◽  
Shinji Horiuchi
Keyword(s):  
Star Formation ◽  
Radio Telescope ◽  
Molecular Cloud ◽  
Galactic Plane ◽  
High Mass ◽  
Mass Star ◽  
Giant Molecular Clouds ◽  
Molecular Line ◽  
Star Forming ◽  
Star Formation Regions

AbstractHigh-mass stars are known to be born within giant molecular clouds (GMCs); However, the exact processes involved in forming a high-mass star are still not well understood. It is clear that high-mass stars do not form in isolation, and that the processes surrounding high-mass star formation may affect the environment of the entire molecular cloud. We are studying the GMC associated with RCW 106 (G333), which is one of the most active massive-star formation regions in the Galactic plane. This GMC, located at l = 333° b = − 0.5°, has been mapped in over 20 molecular line transitions with the Mopra radio telescope (83-110 GHz), in Australia, and with the Swedish-ESO Submillimeter Telescope (SEST) in the 1.2 mm cool dust continuum. The region is also within the Spitzer GLIMPSE infrared survey (3.6, 4.5, 5.8, and 8.0 μm) area. We have decomposed the dust continuum using a clump-finding algorithm (CLUMPFIND), and are using the multiple molecular line traditions from the Mopra radio telescope to classify the type and stage of star formation taking place therein. Having accurate physical temperatures of the star forming clumps is essential to constrain other parameters to within useful limits. To achieve this, we have obtained pointed NH3 observations from the Tidbinbilla 70-m radio telescope, in Australia, towards these clumps.

scholarly journals Distance Determinations from 21 cm Interstellar Absorption-line Measurements

1983 ◽  
Vol 103 ◽  
pp. 541-542 ◽  
Author(s):  
S.R. Pottasch ◽  
R. Gathier ◽  
W.M. Goss
Keyword(s):  
Absorption Line ◽  
Radio Telescope ◽  
Galactic Plane ◽  
Planetary Nebulae ◽  
Interstellar Absorption

HI observations at 21 cm have been made with the Westerbork Synthesis Radio Telescope in the direction of six planetary nebulae located in or near the galactic plane (N 7027, 2440, 6537, 6572, 7026, 7354).

scholarly journals A Survey of the Galactic Plane at 85 and 150 MHz

1968 ◽  
Vol 21 (2) ◽  
pp. 185 ◽  
Author(s):  
R Wielebinski ◽  
DH Smith ◽  
X Garzón Cárdenas
Keyword(s):  
Radio Telescope ◽  
Galactic Plane ◽  
Intense Emission

A survey has been made of the intense emission regions along the galactic plane from l = 600 to 2900 at frequencies of 85 and 150 MHz with the 210 ft radio telescope at Parkes. Aerial temperatures were accurately measured, essentially in terms of thermal standards, with a known baselevel. The spectrum and "steps" of the observed emission have been investigated.

scholarly journals Search for and study of pulsars with the Nançay Radio Telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 386-387
Author(s):  
Franck Octau ◽  
Grégory Desvignes ◽  
Ismaël Cognard ◽  
David Champion ◽  
Patrick Lazarus ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Radio Telescope ◽  
Galactic Plane ◽  
Strong Field ◽  
Sampling Time ◽  
Current Status ◽  
Black Widow ◽  
Gravitation Wave ◽  
Tests Of Gravity

AbstractSince the discovery of the first pulsar in 1967, over 2500 pulsars have been discovered. Pulsars enable a broad range of studies: from the study of the properties of the interstellar medium and of pulsar magnetospheres to tests of gravity in the strong-field regime and the characterisation of the cosmological gravitation wave background. These reasons are the main drive for searching for more pulsars. A blind pulsar survey, named SPAN512, was initiated with the Nançay Radio Telescope in 2012. Conducted at 1.4 GHz with a sampling time of 64μs and 500-kHz frequency channels, SPAN512 was designed to search for fast and distant pulsars in the Galactic plane. Here we describe the current status of the survey and present the latest discovery, PSR J2055+3829, a 2.08-ms pulsar in a black widow system.

scholarly journals The High Time Resolution Universe surveys for pulsars and fast transients

2012 ◽  
Vol 8 (S291) ◽  
pp. 29-34 ◽  
Author(s):  
Michael J. Keith
Keyword(s):  
Radio Telescope ◽  
Time Resolution ◽  
Gamma Ray ◽  
Galactic Plane ◽  
High Time ◽  
Frequency Resolution ◽  
High Time Resolution ◽  
Galactic Latitude ◽  
Millisecond Pulsars ◽  
Bank System

AbstractThe High Time Resolution Universe survey for pulsars and transients is the first truly all-sky pulsar survey, taking place at the Parkes Radio Telescope in Australia and the Effelsberg Radio Telescope in Germany. Utilising multibeam receivers with custom built all-digital recorders the survey targets the fastest millisecond pulsars and radio transients on timescales of 64 μs to a few seconds. The new multibeam digital filter-bank system at has a factor of eight improvement in frequency resolution over previous Parkes multibeam surveys, allowing us to probe further into the Galactic plane for short duration signals. The survey is split into low, mid and high Galactic latitude regions. The mid-latitude portion of the southern hemisphere survey is now completed, discovering 107 previously unknown pulsars, including 26 millisecond pulsars. To date, the total number of discoveries in the combined survey is 135 and 29 MSPs These discoveries include the first magnetar to be discovered by it's radio emission, unusual low-mass binaries, gamma-ray pulsars and pulsars suitable for pulsar timing array experiments.

scholarly journals Maser Source-Finding Methods in HOPS

2012 ◽  
Vol 29 (3) ◽  
pp. 262-268 ◽  
Author(s):  
A. J. Walsh ◽  
C. Purcell ◽  
S. Longmore ◽  
C. H. Jordan ◽  
V. Lowe
Keyword(s):  
Radio Telescope ◽  
Galactic Plane ◽  
Spectral Lines ◽  
Intrinsic Nature ◽  
Manual Method ◽  
Noise Characteristics ◽  
Peak Emission ◽  
Extended Emission ◽  
Water Maser

AbstractThe H2O Southern Galactic Plane Survey (HOPS) has observed 100 deg2 of the Galactic plane, using the Mopra radio telescope to search for emission from multiple spectral lines in the 12-mm band (19.5–27.5 GHz). Perhaps the most important of these spectral lines is the 22.2-GHz water-maser transition. We describe the methods used to identify water-maser candidates and subsequent confirmation of the sources. Our methods involve a simple determination of likely candidates by searching peak emission maps, utilising the intrinsic nature of water-maser emission, spatially unresolved and spectrally narrow-lined. We estimate completeness limits and compare our method with results from the duchamp source finder. We find that the two methods perform similarly. We conclude that the similarity in performance is due to the intrinsic limitation of the noise characteristics of the data. The advantages of our method are that it is slightly more efficient in eliminating spurious detections and is simple to implement. The disadvantage is that it is a manual method of finding sources and so is not practical on datasets much larger than HOPS, or for datasets with extended emission that needs to be characterised. We outline a two-stage method for the most efficient means of finding masers, using duchamp.

scholarly journals Pulsar Searches at Effelsberg — Past, Present & Future

2000 ◽  
Vol 177 ◽  
pp. 11-16
Author(s):  
D.R. Lorimer ◽  
M. Kramer
Keyword(s):  
Radio Telescope ◽  
Galactic Plane ◽  
Progress Report ◽  
Galactic Centre ◽  
Bright Future ◽  
The World ◽  
Highly Dispersed ◽  
Pulsar Searches

AbstractIt is fair to say that pulsar searches with the 100-m Effelsberg telescope have had something of a checkered history — after all, for many years, this was the largest radio telescope in the world never to have found a pulsar! This situation has, happily, changed. In this review we summarize recent discoveries of weak pulsars along the Galactic plane, give a progress report on a survey for highly dispersed pulsars in the Galactic centre and, in the spirit of this meeting, speculate on what should be a bright future for pulsar searches with this instrument.

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