J/MNRAS/466/2602 Blazhko effect in Galactic RR Lyrae (Prudil+, 2017)
Blazhko effect in the Galactic bulge fundamental mode RR Lyrae stars.
I. Incidence rate and differences between modulated and non-modulated stars.
Prudil Z., Skarka M.
<Mon. Not. R. Astron. Soc., 466, 2602-2613 (2017)>
=2017MNRAS.466.2602P 2017MNRAS.466.2602P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable
Keywords: methods: data analysis - methods: statistical -
techniques: photometric - stars: horizontal branch -
stars: variables: RR Lyrae
Abstract:
We present the first paper of a series focused on the Blazhko effect
in RR Lyrae type stars pulsating in the fundamental mode that are
located in the Galactic bulge. A comprehensive overview of the
incidence rate and light-curve characteristics of the Blazhko stars is
given. We analysed 8282 stars having the best quality data in the
OGLE-IV survey, and found that at least 40.3 per cent of the stars
show modulation of their light curves. The number of Blazhko stars we
identified is 3341, which is the largest sample ever studied, implying
that these are the most relevant statistical results currently
available. Using combined data sets with OGLE-III observations, we
found that 50 per cent of the stars that show unresolved peaks close
to the main component in OGLE-IV are actually Blazhko stars with
extremely long periods. Blazhko stars with modulation occur
preferentially among RR Lyrae stars with shorter pulsation periods in
the Galactic bulge. Fourier amplitude and phase coefficients based on
the mean light curves appear to be substantially lower for Blazhko
stars than for stars with an unmodulated light curve on average. We
derived new relations for the compatibility parameter Dm in the I
passband and relations that allow for differentiating modulated and
non-modulated stars easily based on R31, φ21 and φ31.
Photometric metallicities, intrinsic colours and absolute magnitudes
computed using empirical relations are the same for Blazhko and
non-modulated stars in the Galactic bulge, suggesting there is no
correlation between the occurrence of the Blazhko effect and these
parameters.
Description:
In 2014, the first data gathered by OGLE-IV for more than 38000 RRL
type stars (27258 of RRab type) located in the GB were publicly
released. Together with photometric data, Soszynski et al. (2014, Cat.
J/AcA/64/177) published a complete catalogue with light ephemerides,
mean brightness, peak-to-peak amplitudes and Fourier coefficients,
which we adopted for further analysis.
Our final sample contains 8282 stars that have between 420 and 8334
data points (median 1016), and is presented in table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 43 8282 BL stars
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See also:
J/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I05 --- OGLE OGLE identification number
(OGLE BLG-RRLYR-NNNNN in Simbad)
7- 9 A3 --- Group Group (1)
11 I1 --- K2-9 [0/2] observability in Kepler K2 campaigns 9 (2)
13 I1 --- K2-11 [0/2] observability in Kepler K2 campaigns 11 (2)
15- 18 A4 --- Rem Remarks (3)
20- 24 F5.3 --- RT Rise time (phase difference between maximum
and minimum light)
26- 30 F5.2 [-] [Fe/H] ?=- Metallicity
32- 36 F5.3 mag (V-I)0 ?=- Deredenned V-I colour index
38- 43 F6.3 mag iMAG ?=- Absolute i magnitude
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Note (1): Groups as follows:
BL = BL star
PC = PC star
cBL = candidate star
nBL = non-modulated star
Note (2): Flag as follows:
0 = not on silicon
1 = near silicon
2 = on silicon
Note (3): Remarks as follows:
a = only one side peak was detected
b = possible blend
lm = modulation period is longer than 2/3 TS
h = side peaks were identified in higher pulsation harmonics first
c = star is present in Collinge, Sumi & Fabrycky (2006, Cat J/ApJ/651/197)
m = star is present in Moskalik & Poretti (2003A&A...398..213M 2003A&A...398..213M)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Oct-2019