Reduction of spatial effects on emission line intensity observed from single aerosol particles via diffuse reflectance from an integrating sphere

2002 ◽  
Author(s):  
Emily Gibb ◽  
Erica Corbett ◽  
Igor Gornushkin ◽  
Ben Smith ◽  
David Hahn ◽  
...  
Keyword(s):  
Emission Line ◽  
Line Intensity ◽  
Diffuse Reflectance ◽  
Aerosol Particles ◽  
Integrating Sphere ◽  
Spatial Effects

scholarly journals A UV Flare at the Center of the Elliptical Galaxy NGC 4552

1999 ◽  
Vol 194 ◽  
pp. 389-393 ◽  
Author(s):  
Lucio M. Buson ◽  
Francesco Bertola ◽  
David Burstein ◽  
Michele Cappellari ◽  
Sperello di Serego Alighieri ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Emission Line ◽  
Line Intensity ◽  
Elliptical Galaxy ◽  
Line Profiles ◽  
Massive Black Hole ◽  
Self Consistent ◽  
Intensity Ratios

A self-consistent analysis of near-UV, HST/FOC images of the elliptical galaxy NGC 4552 is used to show that its central spike has brightened by a factor ˜ 4.5 between 1991 and 1993, and has decreased its luminosity by a factor ˜ 2.0 between 1993 and 1996. A strong UV continuum over the energy distribution of the underlying galaxy is concurrently revealed shortward of λ ˜ 3200 Å by our FOS spectra extending from the near-UV to red wavelengths. Nuclear emission-line profiles of both permitted and forbidden lines are best modelled with a combination of broad and narrow components, with FWHM of ˜ 3000 km s−1 and ˜ 700 km s−1, respectively. Current diagnostics based on the emission line intensity ratios definitely places the spike among AGNs, just at the border between Seyferts and LINERs. This evidence argues for the variable central spike being produced by a modest accretion event onto a central massive black hole (BH), with the accreted material having possibly being stripped from a star in a close fly-by with the BH. In this regard, one has to look at NGC 4552 as the faintest known AGN.

scholarly journals Variable Spectra of IC 4997 and NGC 6572

1993 ◽  
Vol 155 ◽  
pp. 488-488
Author(s):  
Siek Hyung ◽  
Lawrence H. Aller ◽  
Walter A. Feibelman
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
Line Intensity ◽  
Planetary Nebula ◽  
Radiative Flux ◽  
Gradual Decrease ◽  
High Dispersion ◽  
Echelle Spectrograph

Variability of the [OIII]4363/4340 H γ ratio in IC 4007 was established in 1956 by William Liller and L.H. Aller who attributed the changes to a gradual decrease of electron density with time. Subsequent 4363/4340 ratio fluctuations negated this explanation. Ferland pointed out that small changes in the radiative flux of the Planetary nebula nucleus (PNN) could explains the variations. Our pervious study emphasized IUE observations, here we compare high dispersion spectra obtained with the Hamilton Echelle Spectrograph with previous measurements to asses line intensity variations. Emission line variability in PNN spectra as noted by Mendez et al. (1988) and by other for HeII 4686 in NGC 6572 may offer significant clues. PNN 4686 appeared by 1990 in IC 4997. Possibly both of these PNN may be evolving into Wolf-Rayet objects, but this development does not necessarily imply that the nebular excitation will increase with time.

RELATIVE TRANSITION PROBABILITIES IN NEON

1966 ◽  
Vol 44 (8) ◽  
pp. 1781-1786 ◽  
Author(s):  
J. C. Irwin ◽  
R. A. Nodwell
Keyword(s):  
Emission Line ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Atomic Transition ◽  
Temperature Measurements ◽  
Intensity Measurements ◽  
Relative Transition ◽  
Reversal Temperature

The relative atomic transition probabilities for the transitions between the 2p53p and 2p53s configurations of NeI have been measured by combining reversal temperature measurements with relative emission line intensity measurements. The relative emission intensities were corrected for self-absorption. The results are compared with those obtained by previous workers.

scholarly journals Emission-Line Intensity Ratios in F[CLC]e[/CLC] [CSC]xvii[/CSC] Observed with a Microcalorimeter on an Electron Beam Ion Trap

2000 ◽  
Vol 545 (2) ◽  
pp. L161-L164 ◽  
Author(s):  
J. M. Laming ◽  
I. Kink ◽  
E. Takacs ◽  
J. V Porto ◽  
J. D. Gillaspy ◽  
...  
Keyword(s):  
Electron Beam ◽  
Emission Line ◽  
Line Intensity ◽  
Ion Trap ◽  
Electron Beam Ion Trap ◽  
Intensity Ratios

Measurement of Diffuse Reflectance Spectrum of Biological Material with Single Integrating-Sphere

2011 ◽  
Vol 321 ◽  
pp. 252-255
Author(s):  
Lian Shun Zhang ◽  
Lei Fu ◽  
Kong Yang Zhao
Keyword(s):  
Biological Material ◽  
Diffuse Reflectance ◽  
Reflectance Spectrum ◽  
Diffuse Reflectance Spectrum ◽  
Experimental System ◽  
Integrating Sphere ◽  
Light Sources ◽  
Human Breast ◽  
Human Breast Tissue ◽  
Halogen Light

Detection of interactions between light and biological material can be used to characterize the optical properties of the biological material. The purpose of this paper is to develop a method that measures the diffuse reflectance spectrum of biological material with single integrating-sphere. The experimental system incorporated a DH-2000 Deuterium Tungsten Halogen Light Sources, USB4000-VIS-NIR Miniature Fiber Optic Spectrometer and an integrating-sphere. Intralipid and ink were used to mimic scattering and absorbing properties of biological material in the tested sample. Total of 30 sample representing of normal and malignant human breast tissue were measured. The measured optical reflectance spectrums with different scattering and absorbing properties were analyzed. The result showed that the diffuse reflectance spectrums of normal and malignant biological material are different in intensity.

Diffuse Reflectance Studies of Edible Fats

2002 ◽  
Vol 56 (8) ◽  
pp. 1094-1097 ◽  
Author(s):  
N. Ghosh ◽  
A. Datta ◽  
P. K. Gupta
Keyword(s):  
Light Scattering ◽  
Absorption Coefficient ◽  
Diffuse Reflectance ◽  
Reflectance Spectra ◽  
Integrating Sphere ◽  
Diffuse Reflectance Spectra ◽  
Edible Fats ◽  
Partially Hydrogenated Vegetable Oil ◽  
Hydrogenated Vegetable Oil ◽  
Absorption Characteristics

Light scattering properties of ghee (a form of clarified butter) and vanaspati (partially hydrogenated vegetable oil) have been investigated in order to explore the use of optical techniques for detection of adulteration of vanaspati in ghee. Significant differences in the diffuse reflectance spectra of ghee and vanaspati were observed. The estimates for the reduced scattering coefficient (μs′) and the absorption coefficient (μa) for ghee and vanaspati were also obtained from integrating sphere measurements. These suggest that the differences in the diffuse reflectance spectra of ghee and vanaspati are primarily due to the differences in their absorption characteristics in the spectral range of 400 to 550 nm. Further, the results obtained show that the ratio of diffuse reflectance at 460 nm to that at 410 nm could be used to detect adulteration of vanaspati in ghee.

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