Spatially resolved spectroscopic observations of Jupiter during the 1987 opposition

1989 ◽  
Vol 46 (3) ◽  
pp. 207-219 ◽  
Author(s):  
F. Moreno ◽  
A. Molina
Keyword(s):  
Spectroscopic Observations ◽  
Spatially Resolved

scholarly journals First Results on Clusters Observed by XMM/EPIC

2002 ◽  
Vol 12 ◽  
pp. 507-509
Author(s):  
M. Arnaud ◽  
N. Aghanim ◽  
E. Belsole ◽  
R. Gastaud ◽  
S. Majerowicz ◽  
...  
Keyword(s):  
Spectroscopic Observations ◽  
Dynamical State ◽  
Spatially Resolved ◽  
First Results

AbstractFirst spatially resolved spectroscopic observations of the Virgo and Coma clusters made with XMM during the PV phase are presented. The implication for the dynamical state of these clusters are briefly discussed.

scholarly journals The effect of the slit configuration on the H2 1-0 s(1) to Br γ line ratio of spatially resolved planetary nebulae

2020 ◽  
Vol 497 (3) ◽  
pp. 3180-3190
Author(s):  
Isabel Aleman
Keyword(s):  
Numerical Simulations ◽  
Planetary Nebulae ◽  
Line Ratio ◽  
Excitation Mechanism ◽  
Limited Region ◽  
Spectroscopic Observations ◽  
Spatially Resolved ◽  
Peak Emission

ABSTRACT The H2 1-0 S(1)/Br γ ratio (R(Br γ)) is used in many studies of the molecular content in planetary nebulae (PNe). As these lines are produced in different regions, the slit configuration used in spectroscopic observations may have an important effect on their ratio. In this work, observations and numerical simulations are used to demonstrate and quantify such effect in PNe. The study aims to assist the interpretation of observations and their comparison to models. The analysis shows that observed R(Br γ) ratios reach only values up to 0.3 when the slit encompasses the entire nebula. Values higher than that are only obtained when the slit covers a limited region around the H2 peak emission and the Br γ emission is then minimized. The numerical simulations presented show that, when the effect of the slit configuration is taken into account, photoionization models can reproduce the whole range of observed R(Br γ) in PNe, as well as the behaviour described above. The argument that shocks are needed to explain the higher values of R(Br γ) is thus not valid. Therefore, this ratio is not a good indicator of the H2 excitation mechanism as suggested in the literature.

Facular Models, the K-Line, and Magnetic Fields

1977 ◽  
Vol 4 (2) ◽  
pp. 261-264
Author(s):  
G. A. Chapman
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Atomic Physics ◽  
Solar Magnetic Field ◽  
Good Description ◽  
Velocity Fields ◽  
Small Scale ◽  
Solar Magnetic Fields ◽  
Spectroscopic Observations ◽  
Spatially Resolved

Photospheric faculae are now believed to be closely associated with the small-scale solar magnetic field. In order to obtain reliable observations of solar magnetic fields, one needs to have a good description of faculae, which is presently lacking. The problem in obtaining good observational data is severe because faculae are usually not spatially resolved, particularly so in the case of spectroscopic observations. Proper use of spectroscopic observations also requires some knowledge of solar velocity fields and atomic physics in the case of a non LTE analysis. Many of these problems can be avoided by making use of the wings of the Ca II K-line. The wing of this line is unaffected by magnetic and velocity effects. The formation of the line has become increasingly well understood and most of the wing (with the exception of the inner 1 - 2 Å) is formed in LTE. The line is so strong that its formation spans the whole depth of the photosphere.

scholarly journals A Systematic Search for Dual Active Galactic Nuclei in Merging Galaxies (ASTRO-DARING) II: First Results from Long-slit Spectroscopic Observations

2021 ◽  
Vol 162 (6) ◽  
pp. 289
Author(s):  
Yang-Wei Zhang ◽  
Yang Huang ◽  
Jin-Ming Bai ◽  
Xiao-Wei Liu ◽  
Jian-guo Wang ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Systematic Search ◽  
Host Galaxies ◽  
Merging Galaxies ◽  
Spectroscopic Observations ◽  
Spatially Resolved ◽  
Radio Detection ◽  
Faint Object ◽  
First Results

Abstract Building a large sample of kiloparsec (kpc)-scale dual active galactic nuclei (AGNs) among merging galaxies is of vital importance to understand the coevolution between host galaxies and their central super massive black holes (SMBHs). Doing so, with just such a sample, we have developed an innovative method of systematically searching and identifying dual AGNs among kpc-scale merging galaxies and selected 222 candidates at redshifts ≤ 0.25. All the selected candidates have radio detection in the Faint Images of the Radio Sky at Twenty Centimeters survey and at least one of two cores previously revealed as AGN spectroscopically. We report the first results from a systematic search for dual AGNs in merging galaxies (ASTRO-DARING), which consist of spatially resolved long-slit spectroscopic observations of 41 targets selected from our merging galaxies sample carried out between 2014 November and 2017 February, using the Yunnan Faint Object Spectrograph and Camera mounted on the 2.4 meter telescope in Lijiang of Yunnan Observatories. Of these, 16 are likely dual AGNs, and 15 are newly identified. The efficiency of ASTRO-DARING is thus nearly 40%. With this method, we plan to build the first even sample of more than 50 dual AGNs constructed using a consistent approach. Further analysis of the dual AGN sample shall provide vital clues for understanding the coevolution of galaxies and SMBHs.

scholarly journals SPATIALLY RESOLVED SPECTROSCOPIC OBSERVATIONS OF A POSSIBLE E+A PROGENITOR: SDSS J160241.00+521426.9

2011 ◽  
Vol 729 (1) ◽  
pp. 29 ◽  
Author(s):  
K. Matsubayashi ◽  
M. Yagi ◽  
T. Goto ◽  
A. Akita ◽  
H. Sugai ◽  
...  
Keyword(s):  
Spectroscopic Observations ◽  
Spatially Resolved

Spectroscopic Observations of Visual Double Stars

1965 ◽  
Vol 5 ◽  
pp. 109-111
Author(s):  
Frederick R. West
Keyword(s):  
Radial Velocity ◽  
High Dispersion ◽  
Velocity Difference ◽  
Spectrograph Slit ◽  
Spectroscopic Observations ◽  
Double Stars ◽  
Visual Double Stars ◽  
Relative Orbit ◽  
Two Component ◽  
Star Images

There are certain visual double stars which, when close to a node of their relative orbit, should have enough radial velocity difference (10-20 km/s) that the spectra of the two component stars will appear resolved on high-dispersion spectrograms (5 Å/mm or less) obtainable by use of modern coudé and solar spectrographs on bright stars. Both star images are then recorded simultaneously on the spectrograph slit, so that two stellar components will appear on each spectrogram.

Models of Cataclysmic Variables from Photometric and Spectroscopic Data

1979 ◽  
Vol 46 ◽  
pp. 65-74 ◽  
Author(s):  
A.C. Fabian ◽  
J.E. Pringle ◽  
J.A.J. Whelan ◽  
J.A. Bailey
Keyword(s):  
Spectroscopic Data ◽  
Cataclysmic Variables ◽  
System Parameters ◽  
Dwarf Nova ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations

Abstract.Recent photometric and spectroscopic observations of the dwarf nova system Z Cha are discussed. Methods for constraining the system parameters are applied and the disc emissivity is deduced as a function of radius. Indications are found that the disc shrinks in size with increasing time after outburst.

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

FT-IR microspectroscopic analysis of diseased white matter brain tissues

1995 ◽  
Vol 53 ◽  
pp. 968-969
Author(s):  
Steven M. Le Vine ◽  
David L. Wetzel
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Twitcher Mouse ◽  
Grid Pattern ◽  
Marked Contrast ◽  
Spatially Resolved ◽  
Ft Ir ◽  
Ir Microspectroscopy ◽  
Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

Ultra-spatially resolved synchrotron powered FT-IR microspectroscopy of individual cells of biological material

1995 ◽  
Vol 53 ◽  
pp. 884-885
Author(s):  
David L. Wetzel ◽  
John A. Reffner ◽  
Gwyn P. Williams
Keyword(s):  
Thermal Noise ◽  
Spot Size ◽  
Acquisition Time ◽  
Thermal Source ◽  
Signal To Noise ◽  
Spatially Resolved ◽  
Good Spatial Resolution ◽  
Small Spot ◽  
Ft Ir ◽  
Ir Microspectroscopy

Synchrotron radiation is 100 to 1000 times brighter than a thermal source such as a globar. It is not accompanied with thermal noise and it is highly directional and nondivergent. For these reasons, it is well suited for ultra-spatially resolved FT-IR microspectroscopy. In efforts to attain good spatial resolution in FT-IR microspectroscopy with a thermal source, a considerable fraction of the infrared beam focused onto the specimen is lost when projected remote apertures are used to achieve a small spot size. This is the case because of divergence in the beam from that source. Also the brightness is limited and it is necessary to compromise on the signal-to-noise or to expect a long acquisition time from coadding many scans. A synchrotron powered FT-IR Microspectrometer does not suffer from this effect. Since most of the unaperatured beam’s energy makes it through even a 12 × 12 μm aperture, that is a starting place for aperture dimension reduction.

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