J/MNRAS/440/3809 KIC 10670103 frequency spectrum (Reed+, 2014)
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Analysis of the rich frequency spectrum of KIC 10670103 revealing the most
slowly rotating subdwarf B star in the Kepler field.
Reed M.D., Foster H., Telting J.H., Ostensen R.H., Farris L.H., Oreiro R.,
Baran A.S.
=2014MNRAS.440.3809R (SIMBAD/NED BibCode)
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ADC_Keywords: Stars, variable ; Stars, B-type ; Spectroscopy
Keywords: stars: oscillations - subdwarfs
Abstract:
We analyse 2.75yr of Kepler spacecraft observations of the pulsating
subdwarf B star KIC 10670103. These 1.4 million measurements have an
impressive duty cycle of 93.8 per cent, a frequency resolution of
0.017{mu}Hz, and a 5{sigma} detection limit of 0.1 parts-per-thousand
(ppt). We detect 278 periodicities, making KIC 10670103 the richest
pulsating subdwarf B star to date. Frequencies range from 23 to
673{mu}Hz (0.4 and 11.8h), with amplitudes from the detection limit up
to 14 ppt. Follow-up spectroscopic data were obtained from which it
was determined that KIC 10670103 does not show significant radial
velocity variations. Updated atmospheric model fits determined
T_eff_=21485+/-540K, logg=5.14+/-0.05, and logN(He)/N(H)
=-2.60+/-0.04. We identify pulsation modes using asymptotic period
spacings and frequency multiplets. The frequency multiplets indicate a
spin period of 88+/-8d. Of the 278 periodicities detected in KIC
10670103, 163 (59 per cent) have been associated with low-degree
(l<=2) pulsation modes, providing tight constraints for model fitting.
While the data are exquisite, amplitudes (and some frequencies) are
not stable over the course of the observations, requiring tools which
are non-standard for compact pulsators such as sliding Fourier
transforms and Lorentzian fitting. Using the 163 identified pulsation
modes, it is possible to make detailed examinations of the pulsation
structure; including where the pulsation power is concentrated in
radial order, over what frequency range mode trapping is inefficient,
and how power switches between multiplet members.
Description:
From 33 months of nearly continuous Kepler data, we have detected 278
periodicities in KIC 10670103, making it the richest sdBV star
observed, so far. The 93.8 per cent duty cycle provided excellent data
with a 5{sigma} detection limit of 0.1ppt and a resolution of
0.017uHz.
Objects:
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RA (2000) DE Designation(s)
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19 34 39.94 +47 58 11.7 KIC 10670103 = 2MASS J19343993+4758117
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 99 278 The frequency list as a result of Lorentzian
fitting
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- ID Frequency identification
5 A1 --- n_ID [abd] Note on ID (1)
7- 13 F7.3 uHz Freq Frequency
15- 19 F5.3 uHz e_Freq rms uncertainty on Freq (2)
21- 28 F8.2 s Per Period
30- 34 F5.2 s e_Per rms uncertainty on Per (2)
36- 40 F5.2 10-3 Amp Amplitude (in ppt = parts-per-thousand)
42- 47 A6 --- l Best estimate of the mode degree l
49- 55 A7 --- m Azimuthal order m
57- 58 I2 --- n1 ?=- radial overtone n1 fit to
{Pi}_l,n_={Pi}_l,n=0_+n.{Delta}{pi}_l_ (3)
60- 62 I3 --- n2 ?=- radial overtone n2 fit to
{Pi}_l,n_={Pi}_l,n=0_+n.{Delta}{pi}_l_ (3)
64- 67 F4.2 --- dP/DPi1 ?=- Factional deviation from even period
spacing 1 {delta}P/{Delta}{Pi}_1_
69- 72 F4.2 --- dP/DPi2 ?=- Factional deviation from even period
spacing 2 {delta}P/{Delta}{Pi}_2_
74- 78 F5.3 uHz Dnu ?=- {Delta}{nu} Frequency splitting from the
subsequent frequency, if it may be part of a
multiplet
80- 81 A2 --- l_Model [>= ] Limit flag on Model
82 I1 --- Model ?=- Mode degree l based on frequency multiplets
84- 85 A2 --- l_IDCnl [>= ] Limit flag on MIDCnl
86 I1 --- IDCnl ?=- Value of the Ledoux constant from the
frequency splitting (assuming {Delta}m=1)
88- 94 A7 --- PS Period spacing (4)
96- 99 A4 --- M10 Frequency ID notation from Reed et al.
(2010MNRAS.409.1496R)
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Note (2): frequency/period errors are the corresponding Lorentzian linewidths.
Note (3): where {Pi}_l=1,n=0_ was estimated to be close to the radial
fundamental mode.
Note (1): Notes as follows:
a = This multiplet was fitted using Quarters 9 through 15 only.
b = This multiplet was fitted using Quarters 11 through 15 only.
d = The FT peaks in these regions are particularly messy and we only attempted
to fit the most obvious ones rather than all of them
Note (4): c when More periods exist in this region than can be accomodated by
the mode assignment
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History:
From electronic version of the journal
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(End) Patricia Vannier [CDS] 22-May-2017