J/MNRAS/488/3588 Debris discs in medium separation binaries (Yelverton+, 2019)
A statistically significant lack of debris discs in medium separation binary
systems.
Yelverton B., Kennedy G.M., Su K.Y.L., Wyatt M.C.
<Mon. Not. R. Astron. Soc., 488, 3588-3606 (2019)>
=2019MNRAS.488.3588Y 2019MNRAS.488.3588Y (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Photometry, infrared ;
Binaries, orbits ; Stars, distances ; Stars, diameters
Keywords: binaries: general - circumstellar matter
Abstract:
We compile a sample of 341 binary and multiple star systems with the
aim of searching for and characterizing Kuiper belt-like debris discs.
The sample is assembled by combining several smaller samples studied
in previously published work with targets from two unpublished
Herschel surveys. We find that 38 systems show excess emission at 70
or 100µm suggestive of a debris disc. While nine of the discs
appear to be unstable to perturbations from their host binary based on
a simple analysis of their inferred radii, we argue that the evidence
for genuine instability is not strong, primarily because of
uncertainty in the true disc radii, uncertainty in the boundaries of
the unstable regions, and orbital projection effects. The binary
separation distributions of the disc-bearing and disc-free systems are
different at a confidence level of 99.4 per cent, indicating that
binary separation strongly influences the presence of detectable
levels of debris. No discs are detected for separations between ∼25
and 135au; this is likely a result of binaries whose separations are
comparable with typical disc radii clearing out their primordial
circumstellar or circumbinary material via dynamical perturbations.
The disc detection rate is 19+5-3 per cent for binaries wider than
135au, similar to the published results for single stars. Only
8+2-1 per cent of systems with separations below 25au host a
detectable disc, which may suggest that planetesimal formation is
inhibited in binaries closer than a few tens of au, similar to the
conclusions of studies of known planet-hosting binaries.
Description:
We have assembled a sample of 341 binary and multiple star systems,
and modelled their SEDs to identify and characterize debris discs in
these systems. Our sample, defined in Section 2, is a combination of
the systems studied by Trilling et al. (2007ApJ...658.1289T 2007ApJ...658.1289T),
Rodriguez & Zuckerman (2012ApJ...745..147R 2012ApJ...745..147R, Cat. J/ApJ/745/147), and
Rodriguez et al. (2015MNRAS.449.3160R 2015MNRAS.449.3160R, Cat. J/MNRAS/449/3160), and the
systems targeted by the Herschel programmes OT2gkennedy2 (a survey
of visual binaries with well-known orbits) and OT1jdrake011 (a
survey of close binaries).
As we are interested in how the presence of debris depends on the
stellar orbits, for each system in our sample we record the stellar
separations a and, where available, orbital eccentricities e; this
information is presented in Table 1.
The photometry available varies between systems, but all SEDs have a
range of points spanning visible to far-infrared wavelengths. By
construction of the sample, all have an MIPS 70um, PACS 70um, and/or
PACS 100um observation; Table 2 shows the photometry we use in these
bands.
We find that 38 systems in our sample host debris discs, which are
characterized by their fractional luminosity f (i.e. the ratio of
their luminosity to the stellar luminosity) and their temperature
Tdisc. These parameters are listed in Table 3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 423 Information on the orbits of the binaries and
multiple systems in our sample
table2.dat 99 341 Photometry in the MIPS 70um, PACS 70um, and
PACS 100um bands for all systems in our sample
table3.dat 66 39 Results of SED fitting for the 38 systems we
find to have a significant infrared excess
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name System name
13- 23 A11 --- r_Name Reference on Name (1)
25- 28 F4.1 pc Dist Distance obtained from parallax
30- 36 A7 --- Comp Name of the component
38 I1 --- Grade [1/9]? Orbit grade from the Sixth Catalog of
Orbits of Visual Binary Stars (VB6;
Hartkopf, Mason & Worley 2001AJ....122.3472H 2001AJ....122.3472H)
40- 49 F10.7 arcsec aas ? Semimajor axis in arcseconds from VB6 (2)
51- 57 F7.2 AU aau ? Semi major axis in astronomical units VB6 (2)
59- 66 F8.6 --- e ? Eccentricity from VB6 (2)
68- 79 F12.5 AU Saau ? Stellar separation
81- 86 F6.4 --- Se ? Orbital eccentricity
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Note (1): References as follows:
Calibration = Herschel calibration programme
DEBRIS = Herschel DEBRIS programme (Matthews et al. 2010A&A...518L.135M 2010A&A...518L.135M)
DUNES = DUNES survey (Eiroa et al. 2010A&A...518L.131E 2010A&A...518L.131E)
Drake = OT1jdrake011 unpublished Herschel survey
Kennedy = OT2gkennedy2 unpublished Herschel survey
Rodriguez12 = Rodriguez et al. (2012ApJ...745..147R 2012ApJ...745..147R, Cat. J/ApJ/745/147)
Rodriguez15 = Rodriguez et al. (2015MNRAS.449.3160R 2015MNRAS.449.3160R, Cat. J/MNRAS/449/3160)
Trilling07 = Trilling et al. (2007ApJ...658.1289T 2007ApJ...658.1289T)
Note (2): Values from the Sixth Catalog of Orbits of Visual Binary Stars
(VB6; Hartkopf, Mason & Worley 2001AJ....122.3472H 2001AJ....122.3472H)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name System name
13- 19 F7.2 mJy FMIPS ? Observed flux density in the MIPS 70um
band
21- 26 F6.2 mJy e_FMIPS ? Error on FMIPS
28- 34 F7.2 mJy FMIPSp Predicted flux density in the MIPS 70um
band
36- 40 F5.2 --- chiMIPS ? MIPS 70um significance (1)
42- 49 F8.2 mJy FPACS70 ? Observed flux density in the PACS 70um
band
51- 56 F6.2 mJy e_FPACS70 ? Error on FPACS70
58- 64 F7.2 mJy FPACS70p Predicted flux density in the PACS 70um
band
66- 70 F5.2 --- chiPACS70 ? PACS 70um significance (1)
72- 78 F7.2 mJy FPACS100 ? Observed flux density in the PACS 100um
band
80- 84 F5.2 mJy e_FPACS100 ? Error on F80-84
86- 92 F7.2 mJy FPACS100p Predicted flux density in the PACS 100um
band
94- 99 F6.3 --- chiFPACS100 ? PACS 100um significance (1)
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Note (1): The significance of an excess at a given wavelength is defined as
χ=(Fobs-Fpred)/sqrt(σobs2+σpred2), where
Fobs and Fpred are the observed and predicted flux densities
respectively, and σobs and σpred are the corresponding
uncertainties
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name System name
11 A1 --- f_Name [*] Flag on Name (1)
13- 16 F4.1 Lsun Lstar Stellar luminosity
18- 20 I3 K Tdisc Disc temperature
22- 24 I3 K e_Tdisc Error on Tdisc
26- 32 E7.1 --- f Fractional luminosity (disc luminosity to
stellar luminosity ratio)
34- 40 E7.1 --- e_f Error on f
42- 47 E6.2 AU rbb Blackbody disc radii
49- 54 F6.2 AU e_rbb Error on rbb
56- 60 F5.1 AU rdisc True disc radii
62- 66 F5.1 AU e_rdisc Error on rdisc
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Note (1): Flag as follows:
* = HD 95698 is listed twice because we model it with two dust components
of different temperatures
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 15-Dec-2022