scholarly journals Structure of W3(OH) from Very High Spectral Resolution Observations of 5 Centimeter OH Masers

2007 ◽  
Vol 668 (1) ◽  
pp. 331-347 ◽  
Author(s):  
Vincent L. Fish ◽  
Lorant O. Sjouwerman
Keyword(s):  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Very High

Mercury's Na exosphere as seen with very high spectral resolution from the ground, and from space with MESSENGER

2020 ◽  
Author(s):  
Nelly Mouawad ◽  
Judy Chebly ◽  
François Leblanc ◽  
Jonathan Fraine ◽  
Kahil Fatima
Keyword(s):  
Spectral Resolution ◽  
Doppler Shift ◽  
Space Environment ◽  
High Spectral Resolution ◽  
Polar Regions ◽  
University Of Texas ◽  
Intensity Measurements ◽  
Trajectory Approach ◽  
Space Data ◽  
Very High

<p>The MErcury Surface, Space ENvironment, GEochemistry, and Ranging NASA’s spacecraft, known as MESSENGER, flew by Mercury on September 29, 2009. It was the spacecraft’s third and final flyby, before it went into orbit around the planet. The flyby presented a unique trajectory approach and perspective on the planet’s exosphere, not available when in orbit. We present very high spectral resolution ground-based data obtained at the University of Texas McDonald 2.7-m telescope. These data were acquired within hours of the data taken with the Ultraviolet and Visible Spectrometer (UVVS) onboard MESSENGER. Both datasets targeted similar spatial regions, in the polar altitudes of Mercury. We compare the sodium emissions from both measurements in the exosphere. We find that close to the surface, both intensity measurements match, but the intensities fall off differently with altitude, with the MESSENGER data showing an exponential drop off, sharper than that of the ground-based data; an effect that we attribute to atmospheric seeing. In addition, our ground-based data provided Full Width Half Maximum (fwhm) speeds and Doppler shift speeds; our results suggest energetic processes took place in the polar regions on the dusk side of the planet, but arguably on the dawn side as well. We confirm previous conclusions of Leblanc et al. (2008, 2009) where signatures of energetic processes seem to be coupled with high fwhm speeds and intensity peaks. We compare our Doppler shift velocities with previous works, and find agreement within the uncertainties with Potter et al., (2013) on their transit velocity measurements. Although our peak emissions along the terminator vary in structure and in brightness, they do not exhibit distinctive signatures in the intensity profiles at altitudes above the poles, when compared with convolved MESSENGER space data.</p>

scholarly journals Interferometry and Stellar Magnetism

2000 ◽  
Vol 175 ◽  
pp. 174-177 ◽  
Author(s):  
O. Chesneau ◽  
K. Rousselet-Perraut ◽  
F. Vakili
Keyword(s):  
Spectral Resolution ◽  
Angular Resolution ◽  
Zeeman Effect ◽  
High Spectral Resolution ◽  
Sensitivity Threshold ◽  
High Angular Resolution ◽  
Be Stars ◽  
Long Baseline ◽  
Instrumental Polarisation ◽  
Very High

AbstractThe classical detection of magnetic fields in Be stars remains a challenge due to the sensitivity threshold and geometrical cancelation of the field effects. We propose to study the Zeeman effect using Spectro-Polarimetric INterferometry (SPIN) which consists of the simultaneous use of polarimetry and very high angular resolution provided by long baseline interferometers. As monitoring of the instrumental polarisation is mandatory in order to calibrate interferometric observations in any case, the polarised signal is a natural by-product of interferometers. This method will be tested on the GI2T interferometer thanks to its high spectral resolution and its polarimetric capabilities.

scholarly journals Water Vapor in Venus Determined by Airborne Observations of the 8200 Å Band

1974 ◽  
Vol 65 ◽  
pp. 201-201
Author(s):  
Theodore R. Gull ◽  
C. R. O'Dell ◽  
R. A. R. Parker
Keyword(s):  
Water Vapor ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Average Value ◽  
A Value ◽  
Echelle Grating ◽  
Research Aircraft ◽  
Very High ◽  
Differential Spectroscopy

The region of the 8200 Å Band of H2O was studied in spectra of Venus obtained with an echelle grating spectrograph operated at an altitude of 14.6 km in the NASA Learjet research aircraft. Taking advantage of low foreground absorption, observing at a time of velocity quadrature, differential spectroscopy with respect to lunar spectra, and spectrum averaging, we establish a value of H2O of 3 ± 20 μ for the total path over the entire disk. This value differs from earlier studies of the integrated disk but supports the low values recently derived from infrared bands and by very high spectral resolution groundbased studies.These results establish that the average value over the entire disk is quite low but allows that locally larger values may exist as reported by Barker. A more complete description of this work appeared in Icarus21 (1974), 213.

Analysis and Optical Design of Very High Spectral Resolution Imaging Spectrometer of the Atmospheric CO2

2015 ◽  
Vol 35 (7) ◽  
pp. 0722001
Author(s):  
宋文宝 Song Wenbao ◽  
靳阳明 Jin Yangming ◽  
赵知诚 Zhao Zhicheng ◽  
沈为民 Shen Weimin ◽  
范东栋 Fan Dongdong
Keyword(s):  
Spectral Resolution ◽  
Optical Design ◽  
Atmospheric Co2 ◽  
High Spectral Resolution ◽  
Imaging Spectrometer ◽  
Resolution Imaging ◽  
Very High

scholarly journals Direct Evidence for a Bipolar Stellar Wind in NGC 2392

1989 ◽  
Vol 131 ◽  
pp. 458-458
Author(s):  
C.R. O'Dell
Keyword(s):  
Radial Velocity ◽  
Spectral Resolution ◽  
Stellar Wind ◽  
Planetary Nebula ◽  
Direct Evidence ◽  
Position Angle ◽  
Prolate Spheroid ◽  
High Spectral Resolution ◽  
Kinematic Structure ◽  
Very High

Very high spectral resolution slit spectra have been used to investigate the kinematic structure of the double shell planetary nebula NGC 2392, the Eskimo Nebula. Each shell produces a spectrum corresponding to the projected radial velocity, a pattern which varies according to the position angle of the spectrograph's entrance slit. Multiple slit observations were used to determine that the inner shell is an incomplete prolate spheroid pointed almost at the observer and missing the tip ends. The outer shell is nearly spherical and more uniform.

scholarly journals Spectral-Line Surveys at Millimeter and Submillimeter Wavelengths: Impact of Spectral Resolution

2005 ◽  
Vol 13 ◽  
pp. 825-827
Author(s):  
L. M. Ziurys
Keyword(s):  
Spectral Line ◽  
Spectral Resolution ◽  
Broad Band ◽  
High Spectral Resolution ◽  
The Past ◽  
Single Sideband ◽  
Submillimeter Wavelengths ◽  
The Stability ◽  
Millimeter And Submillimeter Wavelengths ◽  
Very High

AbstractMillimeter and submillimeter astronomy has achieved very high spectral resolution (λ/Δλ ≥ 106-107) over the past 20 years. Broad-band spectral-line surveys at these wavelengths have only taken partial advantage of these capabilities. Such surveys could be more effective with an increase in spectral resolution, accompanied by improvement in the stability and bandwidth of spectrometers and the employment of single-sideband detectors.

scholarly journals Mapping spectroscopic uncertainties into prospective methane retrieval errors from Sentinel-5 and its precursor

2015 ◽  
Vol 8 (1) ◽  
pp. 1333-1363
Author(s):  
R. Checa-Garcia ◽  
J. Landgraf ◽  
F. Hase ◽  
H. Tran ◽  
V. Boudon ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Global Scale ◽  
High Spectral Resolution ◽  
Spectroscopic Parameters ◽  
Infrared Spectral ◽  
Retrieval Errors ◽  
Shortwave Infrared ◽  
Very High ◽  
Better Than

Abstract. Sentinel-5 (S5) and its precursor (S5P) are future European satellite missions aiming at global monitoring of methane (CH4) column average dry air mole fractions (XCH4). The spectrometers to be deployed on-board the satellites record spectra of sunlight backscattered from the Earth's surface and atmosphere. In particular, they exploit CH4 absorption in the shortwave infrared spectral range around 1.65 μm (S5 only) and 2.35 μm (both, S5 and S5P) wavelength. Given an accuracy goal of better than 2% for XCH4 to be delivered on regional scales, assessment and reduction of potential sources of systematic error such as spectroscopic uncertainties is crucial. Here, we investigate how spectroscopic errors propagate into retrieval errors on the global scale. To this end, absorption spectra of a ground-based Fourier Transform Spectrometer (FTS) operating at very high spectral resolution serve as estimate for the quality of the spectroscopic parameters. Feeding the FTS fitting residuals as a perturbation into a global ensemble of simulated S5 and S5P-like spectra at relatively low spectral resolution, XCH4 retrieval errors exceed 1% in large parts of the world and show systematic correlations on regional scales, calling for improved spectroscopic parameters.

scholarly journals SWIFTS: on-chip very high spectral resolution spectrometer

2017 ◽  
Author(s):  
E. le Coarer ◽  
J. Ferrand ◽  
J. Boussey ◽  
S. Blaize ◽  
L. G. Venancio ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
High Spectral Resolution ◽  
On Chip ◽  
Very High ◽  
Resolution Spectrometer

The spectral observation of decimetric spikes with very high spectral resolution

2002 ◽  
Vol 45 (S1) ◽  
pp. 106-113 ◽  
Author(s):  
Min Wang ◽  
Changchun Duan ◽  
Ruixiang Xie ◽  
Zhiguo Xia ◽  
Yihua Yan
Keyword(s):  
Spectral Resolution ◽  
Spectral Observation ◽  
High Spectral Resolution ◽  
Very High
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