Developing Automated Spectral Analysis Tools for Interstellar Features Extractionto Support Construction of the 3D ISM Map

2017 ◽  
Vol 12 (S330) ◽  
pp. 243-244
Author(s):  
L. Puspitarini ◽  
R. Lallement ◽  
A. Monreal-Ibero ◽  
H.-C. Chen ◽  
H. L. Malasan ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Spatial Distribution ◽  
Spatial Resolution ◽  
Environmental Conditions ◽  
Equivalent Width ◽  
Global Analysis ◽  
Line Of Sight ◽  
Absorption Data ◽  
Diffuse Interstellar Bands ◽  
Automated Spectral Analysis

AbstractOne of the ways to obtain a detailed 3D ISM map is by gathering interstellar (IS) absorption data toward widely distributed background target stars at known distances (line-of-sight/LOS data). The radial and angular evolution of the LOS measurements allow the inference of the ISM spatial distribution. For a better spatial resolution, one needs a large number of the LOS data. It requires building fast tools to measure IS absorption. One of the tools is a global analysis that fit two different diffuse interstellar bands (DIBs) simultaneously. We derived the equivalent width (EW) ratio of the two DIBs recorded in each spectrum of target stars. The ratio variability can be used to study IS environmental conditions or to detect DIB family.

PROBE — Profile Resolution Obtained by Excitation

1978 ◽  
Vol 32 (4) ◽  
pp. 381-388 ◽  
Author(s):  
R. M. Measures
Keyword(s):  
Spatial Distribution ◽  
Spatial Resolution ◽  
Pump Pulse ◽  
Probe Pulse ◽  
Laser Pulses ◽  
Laser Induced Fluorescence ◽  
Line Of Sight ◽  
Theoretical Formulation ◽  
New Approach ◽  
Fluorescence Methods

A new approach for evaluating, with spatial resolution, the line of sight properties of a specific constituent is proposed. This PROBE (profile resolution obtained by excitation) concept involves the use of two counter-propagating laser pulses; a pump pulse to condition the medium and a probe pulse to interrogate the medium where the pulses overlap. In this way, information regarding the spatial distribution of a species is transformed into temporal information in the form of a change in the amplitude of a returned probe pulse. For certain situations the PROBE technique offers several advantages over scattering or laser induced fluorescence methods. A theoretical formulation of the concept clearly indicates the importance of the lifetime of the pumped state.

scholarly journals Diffuse Interstellar Bands in M33

2013 ◽  
Vol 9 (S297) ◽  
pp. 74-78
Author(s):  
K. T. Smith ◽  
M. A. Cordiner ◽  
C. J. Evans ◽  
N. L. J. Cox ◽  
P. J. Sarre
Keyword(s):  
Equivalent Width ◽  
Milky Way ◽  
Line Of Sight ◽  
Nearby Galaxy ◽  
Diffuse Interstellar Bands ◽  
Upper Limits ◽  
Interstellar Media ◽  
The Relationship

AbstractWe present the first sample of diffuse interstellar bands (DIBs) in the nearby galaxy M33. Studying DIBs in other galaxies allows the behaviour of the carriers to be examined under interstellar conditions which can be quite different from those of the Milky Way, and to determine which DIB properties can be used as reliable probes of extragalactic interstellar media. Multi-object spectroscopy of 43 stars in M33 has been performed using Keck/DEIMOS. The stellar spectral types were determined and combined with literature photometry to determine the M33 reddenings E(B-V)M33. Equivalent widths or upper limits have been measured for the λ5780 DIB towards each star. DIBs were detected towards 20 stars, demonstrating that their carriers are abundant in M33. The relationship with reddening is found to be at the upper end of the range observed in the Milky Way. The line of sight towards one star has an unusually strong ratio of DIB equivalent width to E(B-V)M33, and a total of seven DIBs were detected towards this star.

scholarly journals Spatial distribution of spruce trees in the nature reserve 'Jankove bare' on mt. Kopaonik

2009 ◽  
pp. 191-204
Author(s):  
Branko Stajic ◽  
Milivoj Vuckovic ◽  
Marko Smiljanic
Keyword(s):  
Spatial Distribution ◽  
Tree Growth ◽  
Environmental Conditions ◽  
National Park ◽  
Nature Reserve ◽  
Distance Methods ◽  
Study Results

The methodology and applicability of the study of spatial distribution of trees in Serbian forestry have been insufficiently reported and presented. This paper, based on mathematical?statistical principles, analyses the method of spatial distribution of spruce trees in the Nature Reserve 'Jankove Bare' in the National Park 'Kopaonik'. The following methods in the group of distance methods were applied: Kotar's method (1993), T2?method, and the index of distance dispersion (Johnson, Zimmer, 1985). The study results in a pure uneven-aged spruce stand based on all three methods showed that spruce trees are randomly distributed over the stand area. Therefore, environmental conditions in the study stand can be regarded as homogeneous and equally suitable for tree growth, and there are no significant interactions between the trees, which could cause a higher competition between the trees for nutrients, water, etc.

scholarly journals Compton-Thick AGN in the NuSTAR ERA VII. A joint NuSTAR, Chandra, and XMM-Newton Analysis of Two Nearby, Heavily Obscured Sources

2021 ◽  
Vol 922 (2) ◽  
pp. 159
Author(s):  
A. Traina ◽  
S. Marchesi ◽  
C. Vignali ◽  
N. Torres-Albà ◽  
M. Ajello ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Energy Range ◽  
Active Galactic Nuclei ◽  
Column Density ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Line Of Sight ◽  
Broad Energy Range ◽  
Larger Sample ◽  
Broad Energy

Abstract We present the joint Chandra, XMM-Newton, and NuSTAR analysis of two nearby Seyfert galaxies, NGC 3081 and ESO 565-G019. These are the only two having Chandra data in a larger sample of 10 low-redshift (z ≤ 0.05), candidates Compton-thick (CT) Active Galactic Nuclei selected in the 15–150 keV band with Swift-BAT that were still lacking NuSTAR data. Our spectral analysis, performed using physically motivated models, provides an estimate of both the line-of-sight (l.o.s.) and average (N H,S ) column densities of the two torii. NGC 3081 has a Compton-thin l.o.s. column density N H,z = [0.58–0.62] × 1024 cm−2, but the N H,S , beyond the CT threshold (N H,S = [1.41–1.78] × 1024 cm−2), suggests a “patchy” scenario for the distribution of the circumnuclear matter. ESO 565-G019 has both CT l.o.s. and N H,S column densities (N H,z > 2.31 × 1024 cm−2 and N H,S > 2.57 × 1024 cm−2, respectively). The use of physically motivated models, coupled with the broad energy range covered by the data (0.6–70 keV and 0.6–40 keV, for NGC 3081 and ESO 565-G019, respectively) allows us to constrain the covering factor of the obscuring material, which is C TOR = [0.63–0.82] for NGC 3081, and C TOR = [0.39–0.65] for ESO 565-G019.

scholarly journals Investigations of the Energy Transfer in the Phycobilisome Antenna of Arthrospira platensis Using Femtosecond Spectroscopy

2020 ◽  
Vol 10 (11) ◽  
pp. 4045
Author(s):  
Alexandra Fălămaș ◽  
Sebastian A. Porav ◽  
Valer Tosa
Keyword(s):  
Energy Transfer ◽  
Transient Absorption ◽  
Single Photon ◽  
Global Analysis ◽  
Photon Counting ◽  
Excitation Energy Transfer ◽  
Arthrospira Platensis ◽  
Absorption Data ◽  
Time Resolved ◽  
Photocurrent Amplification

Understanding the energy transfer in phycobilisomes extracted from cyanobacteria can be used for building biomimetic hybrid systems for optimized solar energy collection and photocurrent amplification. In this paper, we applied time-resolved absorption and fluorescence spectroscopy to investigate the ultrafast dynamics in a hemidiscoidal phycobilisome obtained from Arthrospira platensis. We obtained the steady-state and time-resolved optical properties and identified the possible pathways of the excitation energy transfer in the phycobilisome and its components, phycocyanin and allophycocyanin. The transient absorption data were studied using global analysis and revealed the existence of ultrafast kinetics down to 850 fs in the phycobilisome. The fluorescence lifetimes in the nanosecond time-scale assigned to the final emitters in each sample were obtained from the time-correlated single photon counting fluorescence experiments.

scholarly journals Quasars Disks and Cosmology

1987 ◽  
Vol 124 ◽  
pp. 695-696
Author(s):  
Hagai Netzer
Keyword(s):  
Black Hole ◽  
Ultraviolet Radiation ◽  
Equivalent Width ◽  
Selection Effect ◽  
Emission Lines ◽  
Line Of Sight ◽  
Apparent Brightness ◽  
Central Black Hole ◽  
New Ideas ◽  
Thin Disks

Much of the optical and ultraviolet radiation of bright quasars may originate in a massive accretion disk around a central black hole. Most searches for the signature of such disks gave ambiguous results but lately there are new ideas that may lead to their discovery. In particular, the apparent brightness of thin disks depend on their inclination to the observer's line of sight and this may be detected by the equivalent width of some emission lines (Netzer 1985, 1986). This idea may change our view on the inner structure of quasars and other AGN. In addition, it points to a potential selection effect that has not been taken into account so far. Magnitude limited optical quasar samples may contain, preferentially, face-on disks, thus cosmological evolution based on such samples may be biased. There are other implications, especially to the observed correlation of Lop with Lx in quasars.

Development of a Submilli-PIXE Camera

1998 ◽  
Vol 08 (02n03) ◽  
pp. 209-216 ◽  
Author(s):  
S. MATSUYAMA ◽  
K. GOTOH ◽  
K. ISHII ◽  
H. YAMAZAKI ◽  
T. SATOH ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Resolution ◽  
Data Acquisition System ◽  
Beam Line ◽  
Beam Position ◽  
Pixe Analysis ◽  
X Ray ◽  
System A ◽  
Line Beam ◽  
Analysis System

We developed a PIXE analysis system which provides spatial distribution images of elements in a region of several cm2 with a spatial resolution of < 0.5 mm. We call this system a submilli-PIXE camera. This system consists of a submilli-beam line, beam scanners and a data acquisition system in which the X-ray energy and the beam position are simultaneously measured. We demonstrate the usefulness of the submilli-PIXE camera by analyzing the surface of a shell and of granite.

scholarly journals A 3-D tomographic retrieval approach with advection compensation for the air-borne limb-imager GLORIA

2011 ◽  
Vol 4 (11) ◽  
pp. 2509-2529 ◽  
Author(s):  
J. Ungermann ◽  
J. Blank ◽  
J. Lotz ◽  
K. Leppkes ◽  
L. Hoffmann ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
A Priori ◽  
Horizontal Resolution ◽  
Line Of Sight ◽  
Wind Fields ◽  
Closed Curves ◽  
Flight Direction ◽  
Mesoscale Structures ◽  
Priori Information ◽  
Horizontal View

Abstract. Infrared limb sounding from aircraft can provide 2-D curtains of multiple trace gas species. However, conventional limb sounders view perpendicular to the aircraft axis and are unable to resolve the observed airmass along their line-of-sight. GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is a new remote sensing instrument that is able to adjust its horizontal view angle with respect to the aircraft flight direction from 45° to 135°. This will allow for tomographic measurements of mesoscale structures for a wide variety of atmospheric constituents. Many flights of the GLORIA instrument will not follow closed curves that allow measuring an airmass from all directions. Consequently, it is examined by means of simulations, what spatial resolution can be expected under ideal conditions from tomographic evaluation of measurements made during a straight flight. It is demonstrated that the achievable horizontal resolution in the line-of-sight direction could be reduced from over 200 km to around 70 km compared to conventional retrievals and that the tomographic retrieval is also more robust against horizontal gradients in retrieved quantities in this direction. In a second step, it is shown that the incorporation of channels exhibiting different optical depth can further enhance the spatial resolution of 3-D retrievals enabling the exploitation of spectral samples usually not used for limb sounding due to their opacity. A second problem for tomographic retrievals is that advection, which can be neglected for conventional retrievals, plays an important role for the time-scales involved in a tomographic measurement flight. This paper presents a method to diagnose the effect of a time-varying atmosphere on a 3-D retrieval and demonstrates an effective way to compensate for effects of advection by incorporating wind-fields from meteorological datasets as a priori information.

Fully automated spectral analysis of periodic signals

2003 ◽  
Vol 52 (4) ◽  
pp. 1021-1024 ◽  
Author(s):  
J. Schoukens ◽  
Y. Rolain ◽  
G. Simon ◽  
R. Pintelon
Keyword(s):  
Spectral Analysis ◽  
Periodic Signals ◽  
Automated Spectral Analysis

A Discussion on the physics of the solar atmosphere - Spectroscopic studies of the solar corona at x-ray wavelengths

1976 ◽  
Vol 281 (1304) ◽  
pp. 383-390 ◽  
Keyword(s):  
Spatial Distribution ◽  
Solar Corona ◽  
Spatial Variation ◽  
Resonance Line ◽  
Active Regions ◽  
Resonance Scattering ◽  
Spectroscopic Studies ◽  
Line Of Sight ◽  
X Ray ◽  
Forbidden Transitions

The spatial distribution of the emission in several X-ray lines is discussed with emphasis on temperature dependence and association with active regions. New results are presented for the trio of helium-like O vii lines which demonstrate (1) a spatial variation in the density dependent forbidden to intersystem line ratio, and (2) a strong spatial variation in the intensity of the O vii resonance line relative to the optically forbidden transitions. The second effect appears to be caused by resonance scattering by material in the line of sight.

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