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Now showing items 11-20 of 21
Linking multi-epoch CCD photometry of partially overlapping fields
(Oxford University Press, 2013)
A common problem in CCD photometry is to combine measurements obtained at different
epochs. This is especially challenging if the fields only overlap partially, and are sparse, so
that not all calibrating stars are ...
What can be deduced from open cluster metallicity measurements?
(Oxford University Press, 2007)
The dependence of [Fe/H] on galactocentric distance, distance from the galactic mid-plane
and age is studied. Both ordinary least-squares and non-parametric regression in the form of a
‘generalized additive model’ are ...
Confidence intervals for the correlation between the gamma-ray burst peak energy and the associated supernova peak brightness
(Oxford University Press, 2009)
A strong correlation between the gamma-ray burster peak energy and the peak luminosity
of the associated supernova was discovered by Li for four GRBs. Despite the fact that the
formal significance level of the correlation ...
The detailed forms of the LMC Cepheid PL and PLC relations
(Oxford University Press, 2007)
Possible deviations from linearity of the Large Magellanic Cloud Cepheid period–luminosity
(PL) and period–luminosity–colour (PLC) relations are investigated. Two data sets are studied,
respectively from the Optical ...
The Nyquist frequency for time series with slight deviations from regular spacing
(Oxford University Press, 2009)
The paper is based on the notion that the Nyquist frequency νN is a symmetry point of the
periodogram of a time series: the power spectrum at frequencies above νN is a mirror image
of that below νN. Koen showed that the ...
The analysis of indexed astronomical time series – X. Significance testing of O − C data
(Oxford University Press, 2006)
It is assumed that O − C (‘observed minus calculated’) values of periodic variable stars are
determined by three processes, namely measurement errors, random cycle-to-cycle jitter in
the period, and possibly long-term ...
Is there evolution in the infrared Tully–Fisher relation? Comparing two linear regressions
(Oxford University Press, 2009)
In a recent paper, Puech and co-workers compared K-band Tully–Fisher relations derived
for nearby and distant galaxies, respectively. They concluded that the two relations differ,
and deduced that there is evolution in ...
The “four sigma” limit for significant periodicities
(Springer Verlag, 2010)
Most of the pulsations which have been observed
in sdB stars have very low amplitudes. Detection of modes
from photometric observations is usually performed by noting
the most prominent peaks in a periodogram or, ...
The analysis of irregularly observed stochastic astronomical time-series – I. Basics of linear stochastic differential equations
(Oxford University Press, 2005)
The theory of low-order linear stochastic differential equations is reviewed. Solutions to these
equations give the continuous time analogues of discrete time autoregressive time-series. Explicit
forms for the power ...
A re-assessment of the nearest neighbour alignment of the X-ray isophotes of galaxy clusters
(Oxford University Press, 2006)
Alignment is defined as the tendency of the distribution of pointing angles between the major
axes of clusters and their nearest neighbours to be more concentrated towards small values
for small nearest neighbour distances, ...