scholarly journals Densely folded spectral images of the CCD spectrometer working in the full 200-1000nm wavelength range with high resolution

2005 ◽  
Vol 13 (25) ◽  
pp. 10049 ◽  
Author(s):  
Yue-Rui Chen ◽  
Bin Sun ◽  
Tao Han ◽  
Yu-Fei Kong ◽  
Cong-Hui Xu ◽  
...  
Keyword(s):  
High Resolution ◽  
Wavelength Range

scholarly journals Theoretical Modeling of High-Resolution X-ray Spectra Emitted by Tungsten and Molybdenum Ions from Tokamak Plasmas

2020 ◽  
Vol 39 (5) ◽  
pp. 194-201
Author(s):  
Ł. Syrocki ◽  
K. Słabkowska ◽  
E. Węder ◽  
M. Polasik ◽  
J. Rzadkiewicz
Keyword(s):  
High Temperature ◽  
High Resolution ◽  
Detailed Analysis ◽  
Electron Density ◽  
Wavelength Range ◽  
Tokamak Plasmas ◽  
Temperature Plasma ◽  
X Ray ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to allow the advanced interpretation of the X-ray spectra registered by the high-resolution crystal KX1 spectrometer on the JET with an ITER-like wall, especially to determine how the relative emission contributions of tungsten and molybdenum ions change during a JET discharge, the X-ray spectra have been carefully modeled over a narrow wavelength range. The simulations have been done in the framework of Collisional–Radiative model implemented in Flexible Atomic Code for an electron density (ne = 2.5 × 1019 m−3), and electron temperatures between Te = 3.0 keV and Te = 4.5 keV, typical for JET. Moreover, performed detailed analysis in the framework of the proposed procedure can be useful in determining temperature of a high temperature plasma generated in tokamaks.

scholarly journals ESO Spectroscopic Facility

2017 ◽  
Vol 13 (S334) ◽  
pp. 242-247
Author(s):  
Luca Pasquini ◽  
B. Delabre ◽  
R. S. Ellis ◽  
J. Marrero ◽  
L. Cavaller ◽  
...  
Keyword(s):  
High Resolution ◽  
Wavelength Range ◽  
Focal Plane ◽  
Working Group ◽  
Field Of View ◽  
High Resolution Spectroscopy ◽  
Wide Field ◽  
Low Resolution ◽  
Field Unit ◽  
Integral Field

AbstractWe present the concept of a novel facility dedicated to massively-multiplexed spectroscopy. The telescope has a very wide field Cassegrain focus optimised for fibre feeding. With a Field of View (FoV) of 2.5 degrees diameter and a 11.4m pupil, it will be the largest etendue telescope. The large focal plane can easily host up to 16.000 fibres. In addition, a gravity invariant focus for the central 10 arc-minutes is available to host a giant integral field unit (IFU). The 3 lenses corrector includes an ADC, and has good performance in the 360-1300 nm wavelength range. The top level science requirements were developed by a dedicated ESO working group, and one of the primary cases is high resolution spectroscopy of GAIA stars and, in general, how our Galaxy formed and evolves. The facility will therefore be equipped with both, high and low resolution spectrographs. We stress the importance of developing the telescope and instrument designs simultaneously. The most relevant R&D aspect is also briefly discussed.

scholarly journals CARMENES – M Dwarfs and their Planets: First Results

2016 ◽  
Vol 12 (S328) ◽  
pp. 46-53 ◽  
Author(s):  
A. Quirrenbach ◽  
P.J. Amado ◽  
I. Ribas ◽  
A. Reiners ◽  
J.A. Caballero ◽  
...  
Keyword(s):  
High Resolution ◽  
Radial Velocity ◽  
Wavelength Range ◽  
Southern Spain ◽  
Science Program ◽  
Velocity Measurements ◽  
M Dwarfs ◽  
First Results ◽  
Calar Alto

AbstractCARMENES is a pair of high-resolution (R ≳ 80, 000) spectrographs covering the wavelength range from 0.52 to 1.71 μm with only small gaps. The instrument has been optimized for precise radial velocity measurements. It was installed and commissioned at the 3.5 m telescope of the Calar Alto observatory in Southern Spain in 2015. The first large science program of CARMENES is a survey of ~300 M dwarfs, which started on Jan 1, 2016. We present an overview of the instrument, and provide a few examples of early science results.

scholarly journals Combining low- to high-resolution transit spectroscopy of HD 189733b

2018 ◽  
Vol 612 ◽  
pp. A53 ◽  
Author(s):  
Lorenzo Pino ◽  
David Ehrenreich ◽  
Aurélien Wyttenbach ◽  
Vincent Bourrier ◽  
Valerio Nascimbeni ◽  
...  
Keyword(s):  
High Resolution ◽  
Wavelength Range ◽  
Near Infrared ◽  
Theoretical Models ◽  
Apparent Size ◽  
Transmission Spectra ◽  
Infrared Transmission ◽  
Line Spread Function ◽  
Building Models ◽  
Exoplanetary Atmospheres

Space-borne low- to medium-resolution (ℛ ~ 102–103) and ground-based high-resolution spectrographs (ℛ ~ 105) are commonly used to obtain optical and near infrared transmission spectra of exoplanetary atmospheres. In this wavelength range, space-borne observations detect the broadest spectral features (alkali doublets, molecular bands, scattering, etc.), while high-resolution, ground-based observations probe the sharpest features (cores of the alkali lines, molecular lines). The two techniques differ by several aspects. (1) The line spread function of ground-based observations is ~103 times narrower than for space-borne observations; (2) Space-borne transmission spectra probe up to the base of thermosphere (P ≳ 10−6 bar), while ground-based observations can reach lower pressures (down to ~10−11 bar) thanks to their high resolution; (3) Space-borne observations directly yield the transit depth of the planet, while ground-based observations can only measure differences in the apparent size of the planet at different wavelengths. These differences make it challenging to combine both techniques. Here, we develop a robust method to compare theoretical models with observations at different resolutions. We introduce πη, a line-by-line 1D radiative transfer code to compute theoretical transmission spectra over a broad wavelength range at very high resolution (ℛ ~ 106, or Δλ ~ 0.01 Å). An hybrid forward modeling/retrieval optimization scheme is devised to deal with the large computational resources required by modeling a broad wavelength range ~0.3–2 μm at high resolution. We apply our technique to HD 189733b. In this planet, HST observations reveal a flattened spectrum due to scattering by aerosols, while high-resolution ground-based HARPS observations reveal sharp features corresponding to the cores of sodium lines. We reconcile these apparent contrasting results by building models that reproduce simultaneously both data sets, from the troposphere to the thermosphere. We confirm: (1) the presence of scattering by tropospheric aerosols; (2) that the sodium core feature is of thermospheric origin. When we take into account the presence of aerosols, the large contrast of the core of the sodium lines measured by HARPS indicates a temperature of up to ~10 000K in the thermosphere, higher than what reported in the literature. We also show that the precise value of the thermospheric temperature is degenerate with the relative optical depth of sodium, controlled by its abundance, and of the aerosol deck.

High-resolution x-ray spectrum of a laser-produced barium plasma in the 9.10–9.36-Å wavelength range

1998 ◽  
Vol 58 (3) ◽  
pp. 1859-1866 ◽  
Author(s):  
R. Doron ◽  
E. Behar ◽  
M. Fraenkel ◽  
P. Mandelbaum ◽  
A. Zigler ◽  
...  
Keyword(s):  
High Resolution ◽  
Wavelength Range ◽  
X Ray

scholarly journals Precision versus Accuracy: some astrophysical and operational limitations

1999 ◽  
Vol 170 ◽  
pp. 52-57
Author(s):  
R. E. M. Griffin
Keyword(s):  
High Resolution ◽  
Wavelength Range ◽  
Spectral Type ◽  
Cross Correlation ◽  
Systematic Errors ◽  
Radial Velocities ◽  
High Dispersion ◽  
Low Level ◽  
Separate Category ◽  
Wide Wavelength Range

AbstractThe measurement of accurate radial velocities for A- or B-type dwarfs poses a separate category of problems: the small number of suitable lines, the wide wavelength range over which such lines are distributed, thermal broadening, rotational broadening, line distortions caused by rotating spots, spectrum variations due to obvious duplicity, and low-level velocity variations due to undetected companion spectra. Moreover, the fact that A- and B-type spectra fall into very distinct groups, each with its own sub-set of the above problems, means that it may be both difficult and unsatisfactory to specify velocity standards, since intrinsic uncertainties caused by differences in spectral type may exceed the measuring errors. The investigation summarized here into the nature and magnitude of some of these intrinsic errors employs wide spans of high-resolution, high-dispersion spectra of Sirius and Vega as ‘natural’ templates. Attention is also drawn to systematic errors which may arise (a) when modelling a cross-correlation ‘dip’ and (b) whenever a spectrum or a cross-correlation dip is measured in the unavoidable presence of another such spectrum or dip.

scholarly journals Relating Diffuse Interstellar Band Strengths to Line of Sight Properties

2013 ◽  
Vol 9 (S297) ◽  
pp. 132-134
Author(s):  
H. Rashedi ◽  
J. Cami ◽  
N. L. J. Cox ◽  
H. van Winckel
Keyword(s):  
High Resolution ◽  
Wavelength Range ◽  
Preliminary Analysis ◽  
Line Of Sight

AbstractWe present a preliminary analysis of a set of optical (3800-8800 Å) high resolution (R = 80,000) spectra for 69 diffuse interstellar band targets. We carried out a sensitive search for interstellar features in the wavelength range 8470-8740 Å that will be covered by the upcoming GAIA mission. We also investigate how the λ8620Å DIB strength varies as a function of other interstellar parameters (other DIBs, E(B-V) and atomic and molecular column densities).

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