scholarly journals An Imaging Survey of Northern Galactic Hα Emission with Arcminute Resolution

1998 ◽  
Vol 15 (1) ◽  
pp. 147-148 ◽  
Author(s):  
Brian Dennison ◽  
John H. Simonetti ◽  
Gregory A. Topasna
Keyword(s):  
Galactic Plane ◽  
Background Radiation ◽  
Emission Measure ◽  
High Sensitivity ◽  
Interference Filter ◽  
Low Noise ◽  
High Quantum Efficiency ◽  
Star Forming ◽  
Microwave Background Radiation ◽  
Line Imaging

AbstractWe present preliminary results from a high-resolution, high-sensitivity imaging survey of the northern galactic Hα emission. The survey is carried out using the Spectral Line Imaging Camera (SLIC) which incorporates a fast (f/1·2) lens attached to a cryogenic CCD in combination with a narrowband interference filter. The pixel size is 1·6 arcminutes and the diameter of each field is 10°. The fast optics, narrow bandpass (1·7 nm) filter, and high quantum-efficiency, low-noise CCD yield a high brightness sensitivity to Hα emission on arcminute scales. This gives an equivalent sensitivity to emission measure structure below 1 pc cm−6. Some faint features detected include a supershell connected with the star forming region W4 extending 7° above the galactic plane, and filaments possibly related to galactic loops II and III. In addition, we have carried out deep observations of fields in which anisotropies in the cosmic microwave background radiation have been detected. Our observations place stringent limits upon the contribution to the apparent microwave fluctuations from free–free emission in the galactic foreground.

scholarly journals GASTON: Galactic Star Formation with NIKA2. Evidence for the mass growth of star-forming clumps

2021 ◽  
Author(s):  
A J Rigby ◽  
N Peretto ◽  
R Adam ◽  
P Ade ◽  
M Anderson ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Galactic Plane ◽  
High Sensitivity ◽  
High Mass ◽  
Evolutionary Stage ◽  
Mass Star ◽  
Mass Growth ◽  
Star Forming ◽  
Compact Source

Abstract Determining the mechanism by which high-mass stars are formed is essential for our understanding of the energy budget and chemical evolution of galaxies. By using the New IRAM KIDs Array 2 (NIKA2) camera on the Institut de Radio Astronomie Millimétrique (IRAM) 30-m telescope, we have conducted high-sensitivity and large-scale mapping of a fraction of the Galactic plane in order to search for signatures of the transition between the high- and low-mass star-forming modes. Here, we present the first results from the Galactic Star Formation with NIKA2 (GASTON) project, a Large Programme at the IRAM 30-m telescope which is mapping ≈2 deg2 of the inner Galactic plane (GP), centred on ℓ = 23${_{.}^{\circ}}$9, b = 0${_{.}^{\circ}}$05, as well as targets in Taurus and Ophiuchus in 1.15 and 2.00 mm continuum wavebands. In this paper we present the first of the GASTON GP data taken, and present initial science results. We conduct an extraction of structures from the 1.15 mm maps using a dendrogram analysis and, by comparison to the compact source catalogues from Herschel survey data, we identify a population of 321 previously-undetected clumps. Approximately 80 per cent of these new clumps are 70 μm-quiet, and may be considered as starless candidates. We find that this new population of clumps are less massive and cooler, on average, than clumps that have already been identified. Further, by classifying the full sample of clumps based upon their infrared-bright fraction – an indicator of evolutionary stage – we find evidence for clump mass growth, supporting models of clump-fed high-mass star formation.

The TopHat Cosmic Microwave Background Anisotropy Experiment

2005 ◽  
Vol 201 ◽  
pp. 65-70
Author(s):  
Robert F. Silverberg ◽  
Keyword(s):  
Cosmic Microwave Background ◽  
Large Scale ◽  
Background Radiation ◽  
High Sensitivity ◽  
Microwave Background ◽  
Long Duration ◽  
Cosmic Microwave Background Anisotropy ◽  
Microwave Background Radiation ◽  
The Universe ◽  
Large Scale Structure Formation

We have developed a balloon-borne experiment to measure the Cosmic Microwave Background Radiation anisotropy on angular scales from ˜50° down to ˜20′. The instrument observes at frequencies between 150 and 690 GHz and will be flown on an Antarctic circumpolar long duration flight. To greatly improve the experiment performance, the front-end of the experiment is mounted on the top of the balloon. With high sensitivity, broad sky coverage, and well-characterized systematic errors, the results of this experiment can be used to strongly constrain cosmological models and probe the early stages of large-scale structure formation in the Universe.

scholarly journals An Hα Survey of the Galactic Plane

1998 ◽  
Vol 179 ◽  
pp. 179-181
Author(s):  
Q.A. Parker ◽  
S. Phillipps
Keyword(s):  
Galactic Plane ◽  
Narrow Band ◽  
Interference Filter ◽  
Low Noise ◽  
Magellanic Clouds ◽  
Coverage Depth ◽  
Ionized Gas ◽  
Fine Grain ◽  
The Galaxy ◽  
Very High

We describe a major new Anglo-Australian proposal for a U.K. Schmidt Telescope (UKST) Hα survey of the Southern Galactic plane, Magellanic clouds and selected regions. The agreed survey will use a new 12 × 12 inch monolithic Hα interference filter of very high specification in combination with Tech Pan film. Tech Pan offers significant advantages for this work due to an inherent sensitivity at Hα and its extremely fine grain, high resolution, exceptional DQE, excellent imaging and low noise (e.g., Parker et al. 1994). The combination of Tech Pan and a narrow band Hα filter will provide a survey of unprecendented area coverage, depth and resolution, superior to any previous optical survey of ionized gas in the galaxy. It should to lead to exciting new discoveries and avenues of research.

scholarly journals A UKST Hα Survey of the Galactic Plane

1997 ◽  
Vol 14 (1) ◽  
pp. 123-124 ◽  
Author(s):  
Q. A. Parker ◽  
Q. S. Phillipps
Keyword(s):  
High Resolution ◽  
Galactic Plane ◽  
Interference Filter ◽  
Low Noise ◽  
Magellanic Clouds ◽  
Area Coverage ◽  
Coverage Depth ◽  
Fine Grain ◽  
The Galaxy ◽  
Peak Sensitivity

AbstractWe describe a major Anglo-Australian project to undertake a UKST Ha survey of the Southern Galactic plane, Magellanic clouds and selected regions. The survey will use a new 12 × 12 inch monolithic Hα interference filter of high specification and Tech Pan film which offers significant advantages over other emulsions due to its peak sensitivity at Ha and its extremely fine grain, high resolution, exceptional DQE, excellent imaging and low noise. A survey of unprecedented area coverage, depth and resolution should result, superior to any previous optical survey of ionised gas in the galaxy. It is certain to lead to exciting new discoveries and new avenues of research.

scholarly journals An Imaging Survey of the Galactic H-Alpha Emission with Arcminute Resolution

1998 ◽  
Vol 179 ◽  
pp. 182-183 ◽  
Author(s):  
B. Dennison ◽  
J.H. Simonetti ◽  
G.A. Topasna ◽  
C. Kelleher
Keyword(s):  
Emission Measure ◽  
Virginia Tech ◽  
Low Noise ◽  
Objective Lens ◽  
Interference Filters ◽  
Alpha Emission ◽  
Imaging Camera ◽  
Hα Emission ◽  
Line Imaging ◽  
Filter Wheel

We are presently carrying out a northern hemisphere survey of the Galactic Hα emission. Our instrument, the Virginia Tech Spectral Line Imaging Camera (SLIC) utilizes a fast objective lens (f/1.2) with a cryogenically-cooled TK 512×512 CCD. A filter wheel in front of the lens allows us to select interference filters, including a narrowband Hα filter and a broader bandpass continuum filter in a line free part of the spectrum. The fast optics in combination with the low noise CCD result in sub-Rayleigh sensitivity at confusion limited levels. (1 Rayleigh = 106/4π photons cm–2 s–1 sr–1.) This corresponds to an emission measure sensitivity of ≈ 1 pc cm–6. Parameters of our system are given in Table 1.

High Sensitivity Observations of the Microwave Background Radiation

1987 ◽  
pp. 55-58
Author(s):  
R. D. Davies ◽  
A. N. Lasenby
Keyword(s):  
Background Radiation ◽  
High Sensitivity ◽  
Microwave Background ◽  
Microwave Background Radiation

DASI: The Degree Angular Scale Interferometer

2005 ◽  
Vol 201 ◽  
pp. 33-42
Author(s):  
E. M. Leitch ◽  
J. E. Carlstrom ◽  
G. Davidson ◽  
M. Dragovan ◽  
N. W. Halverson ◽  
...  
Keyword(s):  
Background Radiation ◽  
Austral Summer ◽  
High Sensitivity ◽  
Current Status ◽  
Research Station ◽  
South Pole ◽  
Microwave Background ◽  
Angular Scale ◽  
Microwave Background Radiation ◽  
The University

We describe the design and current status of the Degree Angular Scale Interferometer (DASI), a compact cm-wave interferometer operating at the Amundsen-Scott South Pole research station. With 20-cm diameter primary antenna elements operating over the frequency range 26 − 36 GHz, DASI is optimized to measure the power spectrum of the cosmic microwave background radiation (CMBR) over the multipole range 140 − 920, (corresponding to scales of 25′ − 2°.6), as well as make high-sensitivity maps of the microwave sky. The telescope was built at the University of Chicago and deployed at the South Pole during the 1999-2000 austral summer.

scholarly journals The 1-Megapixel pnCCD detector for the Small Quantum Systems Instrument at the European XFEL: system and operation aspects

2021 ◽  
Vol 28 (2) ◽  
pp. 576-587
Author(s):  
Markus Kuster ◽  
Karim Ahmed ◽  
Kai-Erik Ballak ◽  
Cyril Danilevski ◽  
Marko Ekmedžić ◽  
...  
Keyword(s):  
Quantum System ◽  
Quantum Efficiency ◽  
Imaging Techniques ◽  
High Sensitivity ◽  
Low Noise ◽  
Nano Particles ◽  
Single Photons ◽  
High Quantum Efficiency ◽  
High Quantum ◽  
Small Quantum

The X-ray free-electron lasers that became available during the last decade, like the European XFEL (EuXFEL), place high demands on their instrumentation. Especially at low photon energies below 1 keV, detectors with high sensitivity, and consequently low noise and high quantum efficiency, are required to enable facility users to fully exploit the scientific potential of the photon source. A 1-Megapixel pnCCD detector with a 1024 × 1024 pixel format has been installed and commissioned for imaging applications at the Nano-Sized Quantum System (NQS) station of the Small Quantum System (SQS) instrument at EuXFEL. The instrument is currently operating in the energy range between 0.5 and 3 keV and the NQS station is designed for investigations of the interaction of intense FEL pulses with clusters, nano-particles and small bio-molecules, by combining photo-ion and photo-electron spectroscopy with coherent diffraction imaging techniques. The core of the imaging detector is a pn-type charge coupled device (pnCCD) with a pixel pitch of 75 µm × 75 µm. Depending on the experimental scenario, the pnCCD enables imaging of single photons thanks to its very low electronic noise of 3 e− and high quantum efficiency. Here an overview on the EuXFEL pnCCD detector and the results from the commissioning and first user operation at the SQS experiment in June 2019 are presented. The detailed descriptions of the detector design and capabilities, its implementation at EuXFEL both mechanically and from the controls side as well as important data correction steps aim to provide useful background for users planning and analyzing experiments at EuXFEL and may serve as a benchmark for comparing and planning future endstations at other FELs.

scholarly journals Background and First Results from the New AAO/UKST Hα Survey

1998 ◽  
Vol 15 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Quentin A. Parker ◽  
Steven Phillipps
Keyword(s):  
Galactic Plane ◽  
Interference Filter ◽  
Low Noise ◽  
Area Coverage ◽  
Coverage Depth ◽  
Fine Grain ◽  
Sensitivity Peak ◽  
The Galaxy ◽  
First Results ◽  
The Uk

AbstractThe UK Schmidt Telescope (UKST) of the Anglo-Australian Observatory (AAO) has just embarked on a new Hα survey of the Southern Galactic Plane, Magellanic Clouds and selected regions using a specially designed, high-specification, monolithic, interference filter. It is probably the largest of its kind for astronomy. It is being used in combination with Kodak Tech Pan film-based emulsion. This emulsion not only has a useful sensitivity peak at Hα but also possesses extremely fine grain and an exceptionally high DQE for the hypersensitised product (∼10%). This leads to excellent imaging, sensitivity and low noise. It is clear that CCDs cannot yet match the wide-area coverage, uniformity and resolution of the UKST/Tech Pan combination for undertaking such a survey. The survey will initially include about 233 Galactic Plane and 40 Magellanic Cloud fields on 4-degree centres and will take about 3 years to complete. Some preliminary images from the new survey are presented and compared with the best previously available from the UKST. Examples of the first survey discoveries, new resolved Galactic planetary nebulae, are also given. This survey will have an unprecedented combination of area coverage, depth and resolution, superior to those of any previous optical survey of ionised gas in the Galaxy. Many new discoveries and research avenues are expected.

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