Mode identification of pulsating stars from line profile variations with the moment method

2008 ◽  
pp. 163-166 ◽  
Author(s):  
C. Aerts
Keyword(s):  
Line Profile ◽  
Moment Method ◽  
Mode Identification ◽  
Pulsating Stars ◽  
The Moment

scholarly journals Mode Identification in Pulsating Stars

1994 ◽  
Vol 162 ◽  
pp. 75-86
Author(s):  
C. Aerts
Keyword(s):  
High Resolution ◽  
Moment Method ◽  
Spectroscopic Methods ◽  
Mode Identification ◽  
Pulsating Stars ◽  
The Past ◽  
Photometric Observations ◽  
The Moment ◽  
Identification Techniques

During the past twenty years, different methods have been developed to identify the modes in non-radially pulsating stars. Before the introduction of high-resolution spectrographs with sensitive detectors, identifications were obtained from photometric observations. More recently, mode identification is obtained by means of spectroscopic methods. In this paper, we present an overview of the different mode-identification techniques currently used and we describe their accuracy to identify the modes present in different kinds of pulsating stars. By means of some applications of the moment method, we show that this method deserves far more attention than it has received until now.

scholarly journals The Slowly Pulsating B Star HD 147394

2002 ◽  
Vol 185 ◽  
pp. 234-235
Author(s):  
M. Briquet ◽  
A. Noels ◽  
C. Aerts ◽  
P. Mathias
Keyword(s):  
Moment Method ◽  
Mode Identification ◽  
The Moment

AbstractHD 147394 is a Slowly Pulsating B star for which we found three periods in the moments of the Si II 4128-4130 lines: f1 = 0.8008 c/d, f2 = 0.7813 c/d and f3 = 0.6710 c/d. A mode identification is perform ed by using the moment method.

scholarly journals Line profile variations in γ Equ: A puzzle

2004 ◽  
Vol 193 ◽  
pp. 287-291 ◽  
Author(s):  
Hiromoto Shibahashi ◽  
Don Kurtz ◽  
Eiji Kambe ◽  
Douglas Gough
Keyword(s):  
Shock Wave ◽  
Line Profile ◽  
Moment Method ◽  
Oscillation Mode ◽  
Alternative Interpretation ◽  
Polar Regions ◽  
Line Shapes ◽  
Photometric Observations ◽  
Rotating Star ◽  
The Moment

AbstractLine profile variations in γ Equ show the classic blue-to-red travelling bumps of m-modes resolved by rotation, and they have been identified as l = 2 or 3, m = −l or −l + 1 by characterising the line shapes using the moment method. The mode identifications cannot be correct, however, since γ Equ is an extremely slowly rotating star (Prot > 70 yr). We propose an alternative interpretation, according to which the observed line profile variations are a manifestation of a shock wave in the high atmosphere near the magnetic polar regions; the oscillation mode is then still consistent with the photometric observations.

scholarly journals Mode Identification of the β Cephei star BW Vulpeculae

1995 ◽  
Vol 155 ◽  
pp. 56-57
Author(s):  
C. Aerts ◽  
T. Van Hoolst ◽  
P. Mathias
Keyword(s):  
Moment Method ◽  
Radial Pulsation ◽  
Mode Identification ◽  
Pulsation Mode ◽  
Non Linear ◽  
Linear Behaviour ◽  
The Moment

AbstractWe identify the pulsation mode of BW Vul by means of both the moment method and the method of photometric amplitudes and find a radial pulsation. We briefly study the non-linear behaviour of BW Vul.

scholarly journals Spectral gap in random bipartite biregular graphs and applications

2021 ◽  
pp. 1-39
Author(s):  
Gerandy Brito ◽  
Ioana Dumitriu ◽  
Kameron Decker Harris
Keyword(s):  
Community Detection ◽  
Adjacency Matrix ◽  
Moment Method ◽  
Coding Theory ◽  
High Probability ◽  
Spectral Gap ◽  
Matrix Completion ◽  
Full Rank ◽  
The Moment ◽  
Deterministic Matrix

Abstract We prove an analogue of Alon’s spectral gap conjecture for random bipartite, biregular graphs. We use the Ihara–Bass formula to connect the non-backtracking spectrum to that of the adjacency matrix, employing the moment method to show there exists a spectral gap for the non-backtracking matrix. A by-product of our main theorem is that random rectangular zero-one matrices with fixed row and column sums are full rank with high probability. Finally, we illustrate applications to community detection, coding theory, and deterministic matrix completion.

Investigation of the Thermodynamic Properties of Anharmonic Crystals with Defects and Influence of Anharmonicity in Exafs by the Moment Method

1998 ◽  
Vol 12 (02) ◽  
pp. 191-205 ◽  
Author(s):  
Vu Van Hung ◽  
Nguyen Thanh Hai
Keyword(s):  
Thermal Expansion ◽  
Thermodynamic Properties ◽  
Phase Change ◽  
Specific Heat ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Moment Method ◽  
Adiabatic Compressibility ◽  
Relative Displacement ◽  
The Moment

By the moment method established previously on the basis of the statistical mechanics, the thermodynamic properties of a strongly anharmonic face-centered and body-centered cubic crystal with point defect are considered. The thermal expansion coefficient, the specific heat Cv and Cp, the isothermal and adiabatic compressibility, etc. are calculated. Our calculated results of the thermal expansion coefficient, the specific heat Cv and Cp… of W, Nb, Au and Ag metals at various temperatures agrees well with the measured values. The anharmonic effects in extended X-ray absorption fine structure (EXAFS) in the single-shell model are considered. We have obtained a new formula for anharmonic contribution to the mean square relative displacement. The anharmonicity is proportional to the temperature and enters the phase change of EXAFS. Our calculated results of Debye–Waller factor and phase change in EXAFS of Cu at various temperatures agrees well with the measured values.

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