J/A+A/332/586 Cataclysmic variables light curves (Bruch 1998)
Studies of the flickering in cataclysmic variables.
IV. Wavelet transforms of flickering light curves
Fritz T., Bruch A.
<Astron. Astrophys. 332, 586 (1998)>
=1998A&A...332..586F 1998A&A...332..586F (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, cataclysmic ; Photometry
Keywords: binaries: close - novae, cataclysmic variables -
methods: data analysis
Abstract:
Wavelet transforms of a large quantity of light curves of numerous CVs
in different photometric states were performed in order to quantify
the behaviour of the flickering in a statistically significant sample
of systems. The scalegram is used as the appropriate tool to describe
the wavelet coefficients of stochastically variable data as a function
of the time scale. The (logarithmic) scalegram being largely linear
for all light curves shows that flickering is a self-similar process
and permits a parametrization in terms of its inclination α and
its value {SIGMA} (flickering strength) at a reference time scale. For
a given system, α and {SIGMA} are stable over many years but can
vary over shorter periods and are then loosely correlated. On average
flickering on short time scales is somewhat bluer than on longer
scales. CVs of different types (and photometric states) occupy
distinct regions in the α-{SIGMA}-plane. This behaviour is
particularly clear cut for novalike variables where UX UMa stars
overlap only slightly with VY Scl stars, and magnetic CVs populate a
small range well separated from the other systems. The intrinsic
flickering amplitudes of most dwarf novae vary around the outburst
cycle with the square root of the system brightness. In dwarf novae
with a strong orbital hump the inclination of the scalegram steepens
during the outburst. Due probably to complex functional dependences
between observable quantities, the physical origins of the flickering,
and dynamical system parameters, no clear correlation (only some
trends) between flickering characteristics and dynamical or
geometrical properties of the CVs can be seen.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 917 List of light curves
table1.tex 47 10267 LaTeX version of the table
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See also:
V/99 : Cataclysmic Binaries and LMXB Catalogue (Ritter+ 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name according to the General Catalogue
of Variable Stars (Cat. II/139)
11- 12 A2 --- Type Type (1)
14- 15 A2 --- subType Subtype (2)
17- 18 A2 --- magType Magnetic type (3)
20- 27 A8 "DD/MM/YY" Date Date
31- 35 I5 d MJD Modified Julian date (MJD=JD-2400000.5)
37- 38 A2 --- PhotState Photometric state (4)
40- 44 A5 --- PhotSys Photometric system (5)
46- 48 I3 min Dur Duration of the light curve
50- 53 F4.1 s TimeRes ? Time resolution
55 A1 --- Band [UBVRI] Photometric band (6)
57- 61 F5.2 --- SIGMA Scalegram parameter Sigma (see main paper)
63- 66 F4.2 --- e_SIGMA rms uncertainty on SIGMA
68- 71 F4.2 --- alpha Scalegram parameter alpha (see main paper)
73- 76 F4.2 --- e_alpha rms uncertainty on alpha
78- 82 F5.2 mag mag ? Mean magnitude during the observations (7)
84- 87 F4.2 mag e_mag ? rms uncertainty on mag
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Note (1): Photometric type of the system
N = classical nova
RN = recurrent nova
NL = novalike variable
UG = dwarf nova
Note (2): Photometric subtype:
A = fast nova
B = slow nova
VY = VY Scl star
UX = UX UMa star
AC = AM CVn star
SS = SS Cyg star
SU = SU UMa star
WZ = WZ Sge star
Z = Z Cam star
Note (3): Magnetic types:
blanc = non-magnetic system (or unknown)
DQ = DQ Her star (intermediate polar)
AM = AM Her star (polar)
Note (4): Photometric state
- = normal state in those systems which do not exhibit different
states (novalike variables and novae; outbursts of the latter
are not considered here), or unknown photometric state
Q = quiescence (dwarf novae in general)
R = rise to outburst (dwarf novae in general)
M = outburst maximum (dwarf novae in general)
D = decline from outburst (dwarf novae in general)
O = unspecified outburst state (dwarf novae in general)
S = standstill (Z Cam stars)
SM = supermaximum (SU UMa stars)
H = high state (VY Scl stars)
L = low state (VY Scl stars)
Note (5): Photometric systems:
UBVRI : UBVRI photometry (if a subset of these letters is given,
the observations were restricted to the corresponding bands)
UBVRI*: Stiening system
white : white light photometry
Note (6): In the case of multicolour photometric systems the photometric
band is indicated to which the subsequent columns refer
Note (7): For light curves in uncalibrated photometric systems a rough
estimate from visual observations is given, otherwise mean
magnitudes and standard deviations corresponding to the
respective photometric band are quoted.
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Acknowledgements: Albert Bruch
(End) Patricia Bauer [CDS] 05-Mar-1998