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Now showing items 11-20 of 55
On multiple classes of gamma-ray bursts, as deduced from autocorrelation functions or bivariate duration/hardness ratio distributions
(Oxford University Press, 2012)
Autocorrelation functions (ACFs) of 119 gamma-ray bursts (GRBs) monitored by the Burst
Alert Telescope (BAT) on Swift are calculated. Contrasting with previous results for smaller
numbers of bursts from other missions, ...
Estimation of the coherence time of stochastic oscillations from modest samples
(Oxford University Press, 2012)
‘Quasi-periodic’ or ‘solar-like’ oscillations can be described by three parameters – a characteristic
frequency, a coherence time (or ‘quality factor’) and the variance of the random
driving process. This paper is concerned ...
IC and RC band time-series observations of some bright ultracool dwarfs
(Oxford University Press, 2005)
The results of more than 100 h of CCD photometric monitoring of 10 L dwarfs and two T dwarfs
are presented. Reasonable evidence is shown for IC band variability in DENIS 0255−4700,
DENIS 1705−0516 and 2M 2104−1037. ...
More on the nature of the variable star UNSW-V-760
(Oxford University Press, 2012)
The results of two multicolour time-series photometric observing runs, separated by about two
months, are presented. The same periodicities previously detected in photometry of UNSWV-
760 are still present, albeit at ...
Fitting power-law distributions to data with measurement errors
(Oxford University Press, 2009)
If X, which follows a power-law distribution, is observed subject to Gaussian measurement
error e, thenX+e is distributed as the convolution of the power-lawand Gaussian distributions.
Maximum-likelihood estimation of ...
Fitting sinusoids to observations of rotating spotted stars
(Oxford University Press, 2007)
It is assumed that K blocks (e.g. seasons) of observations are available, and the parameters
characterizing a fixed-frequency sinusoidal variability (mean light level, amplitude, phase)
are constant within each of the ...
Improved SAAO–2MASS photometry transformations
(Oxford University Press, 2007)
Near-infrared photometry of 599 stars is used to calculate transformations from the South
African Astronomical Observatory (SAAO) JHK system to the Two-Micron All-Sky Survey
(2MASS) JHKS system. Both several-term formal ...
HE0230–4323: an unusual pulsating hot subdwarf star
(Oxford University Press, 2007)
HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not
observable in the optical. Photometric measurements reported in this paper have shown it to be
both a reflection-effect and a ...
Statistical tests for changes in the amplitude, frequency or phase of a sinusoidal variation
(Oxford University Press, 2009)
The problem considered is that of testing for small changes over time in the properties of
a sinusoidal signal contaminated by noise. Two test statistics are proposed. The first is a
frequency domain statistic based on ...
Predicting gamma-ray burster redshifts from their prompt emission properties
(Oxford University Press, 2010)
This paper presents a study of the relation between gamma-ray burster redshift and several
of its prompt emission properties (spectral lag, light curve variability, peak energy, rise time
and the peak bolometric flux ...