J/ApJ/835/209 Orbital nature of 81 ellipsoidal red giant binaries (Nie+, 2017)
The orbital nature of 81 ellipsoidal red giant binaries in the
Large Magellanic Cloud.
Nie J.D., Wood P.R., Nicholls C.P.
<Astrophys. J., 835, 209-209 (2017)>
=2017ApJ...835..209N 2017ApJ...835..209N (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Stars, double and multiple ; Stars, giant ;
Radial velocities ; Stars, diameters
Keywords: binaries: close; Magellanic Clouds; stars: AGB and post-AGB
Abstract:
In this paper, we collect a sample of 81 ellipsoidal red giant
binaries in the Large Magellanic Cloud (LMC), and we study their
orbital natures individually and statistically. The sample contains 59
systems with circular orbits and 22 systems with eccentric orbits. We
derive orbital solutions using the 2010 version of the Wilson-Devinney
code (Wilson & Devinney 1971ApJ...166..605W 1971ApJ...166..605W ; Wilson
1979ApJ...234.1054W 1979ApJ...234.1054W, 1990ApJ...356..613W 1990ApJ...356..613W ; Wilson+ 2009,
J/ApJ/702/403). The sample is selection-bias corrected, and the
orbital parameter distributions are compared to model predictions for
the LMC and to observations in the solar vicinity. The masses of the
red giant primaries are found to range from about 0.6 to 9M☉
with a peak at around 1.5M☉, in agreement with studies of the
star formation history of the LMC, which find a burst of star
formation beginning around 4 Gyr ago. The observed distribution of
mass ratios q=m2/m1 is more consistent with the flat q
distribution derived for the solar vicinity by Raghavan+ (2010,
J/ApJS/190/1) than it is with the solar vicinity q distribution
derived by Duquennoy & Mayor (1991A&A...248..485D 1991A&A...248..485D). There is no
evidence for an excess number of systems with equal mass components.
We find that about 20% of the ellipsoidal binaries have eccentric
orbits, twice the fraction estimated by Soszynski+ (2004,
J/AcA/54/347). Our eccentricity evolution test shows that the
existence of eccentric ellipsoidal red giant binaries on the upper
parts of the red giant branch (RGB) can only be explained if tidal
circularization rates are ∼1/100 the rates given by the usual theory
of tidal dissipation in convective stars.
Description:
The I-band light curve data we use are mainly from OGLE II (Udalski+
1997AcA....47..319U 1997AcA....47..319U; Soszynski+ 2004, J/AcA/54/347; Szymanski
2005AcA....55...43S 2005AcA....55...43S), sometimes supplemented by OGLE III data if it is
published.
The radial velocities are provided by Nie & Wood (2014, J/AJ/148/118)
for 79 ellipsoidal variables, by Nicholls+ (2010, J/MNRAS/405/1770)
for their 11 ellipsoidal variables, and by Nicholls & Wood (2012,
J/MNRAS/421/2616) for their 7 eccentric binaries.
The light curve photometry, supplemented by K-band photometry from the
Two Micron All Sky Survey (2MASS) catalog (Cutri+ 2003, II/246),
provides the K magnitude and the I-K color.
We adopted LMC distance modulus (DM) of 18.49 (de Grijs+
2014AJ....147..122D 2014AJ....147..122D) and reddening E(B-V)=0.08 (Keller & Wood
2006ApJ...642..834K 2006ApJ...642..834K).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 170 81 Orbital solution for each ellipsoidal variable
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/119/1448 : Improved properties for cool stars (Houdashelt+, 2000)
J/AJ/119/1424 : Color-temperature relations of M giants (Houdashelt+, 2000)
J/MNRAS/353/705 : OGLE Variables in Magellanic Clouds (Ita+, 2004)
J/AcA/54/347 : IVB mag of LMC ellipsoidal variables (Soszinski+, 2004)
J/A+A/484/815 : Scaled solar tracks and isochrones (Bertelli+, 2008)
J/AJ/136/1242 : LMC long-period variables from MACHO (Fraser+, 2008)
J/ApJ/702/403 : Photometric observations of V1197 Orionis (Wilson+, 2009)
J/MNRAS/405/1770 : LMC red giants in E sequence (Nicholls+, 2010)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/MNRAS/421/2616 : LMC eccentric ellipsoidal red giant binaries
(Nicholls+, 2012)
J/ApJ/765/L41 : Asteroseismic classification of KIC objects (Stello+, 2013)
J/AJ/148/118 : RV curves of LMC ellipsoidal variables (Nie+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 1 I1 --- Set [1/4] Sample (1)
3- 20 A18 --- OGLE OGLE II identifier (HHMMSS.ss+DDMMSS.s, J2000)
22- 26 F5.1 d Per [65.7/662.2] Orbital period
28- 31 I4 K Teff [3710/5046] Effective Temperature
33- 38 F6.1 d HJD0 Time of light minimum at superior conjunction;
HJD-2450000.0
40- 42 F3.1 d e_HJD0 Uncertainty in HJD0
44- 48 F5.1 km/s Vgamma [212/351] System center of mass radial velocity
50- 52 F3.1 km/s e_Vgamma Uncertainty in Vgamma
54- 57 F4.1 deg i [27.9/90] Inclination (2)
59- 62 F4.1 deg e_i ? Uncertainty in i
64- 68 F5.1 Rsun a [122/601] Semi-major axis, in solar units
70- 73 F4.1 Rsun e_a Uncertainty in a
75- 79 F5.3 --- e [0.05/0.5]?=0 Eccentricity (3)
81- 85 F5.3 --- e_e ? Uncertainty in e
87- 91 F5.3 rad omega [0.3/7.2]? Argument of periastron, ω
93- 97 F5.3 rad e_omega ? Uncertainty in ω
99-103 F5.3 --- q [0.1/1.1] Mass ratio, q
105-109 F5.3 --- e_q Uncertainty in q
111-115 F5.3 --- Omega1 [2.2/6.3] Surface potential, primary, Ω1
117-121 F5.3 --- e_Omega1 Uncertainty in Ω1
123-126 F4.2 Msun Mass1 [0.5/9.4] Mass, primary
128-131 F4.2 Msun e_Mass1 Uncertainty in Mass1
133-136 F4.2 Msun Mass2 [0.09/5] Mass, secondary
138-141 F4.2 Msun e_Mass2 Uncertainty in Mass2
143-147 F5.1 Rsun Rad1 [40/161] Radius, primary
149-153 F5.1 Rsun RadL1 [54/284] Effective Roche lobe radius, primary
155-157 F3.1 Rsun Rad2 [0/3.1] Radius, secondary
159-164 F6.1 Lsun Lum1 [431/6433] Luminosity, primary
166-170 F5.1 Lsun Lum2 [0/807] Luminosity, secondary
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Note (1): Sample as follows:
1 = Circular orbits, Nie & Wood (2014, J/AJ/148/118);
2 = Circular orbits, Nicholls et al. (2010, J/MNRAS/405/1770);
3 = Eccentric orbits, Nie & Wood (2014, J/AJ/148/118);
4 = Eccentric orbits, Nicholls & Wood (2012, J/MNRAS/421/2616).
Note (2): A value of i=90 is an adopted value (see text).
Note (3): Values of e=0.000 apply for systems assumed to have circular orbits.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Aug-2017