J/ApJS/181/62 Survey of young solar analogs (Metchev+, 2009)
The Palomar/Keck adaptive optics survey of young solar analogs: evidence for a
universal companion mass function.
Metchev S.A., Hillenbrand L.A.
<Astrophys. J. Suppl. Ser., 181, 62-109 (2009)>
=2009ApJS..181...62M 2009ApJS..181...62M
ADC_Keywords: Stars, double and multiple ; Stars, masses ; Proper motions ;
Photometry, infrared
Keywords: binaries: visual - stars: imaging - stars: low-mass, brown dwarfs
stars: luminosity function, mass function
Abstract:
We present results from an adaptive optics survey for substellar and
stellar companions to Sun-like stars. The survey targeted 266 F5-K5
stars in the 3Myr-3Gyr age range with distances of 10-190pc. Results
from the survey include the discovery of two brown dwarf companions
(HD 49197B and HD 203030B), 24 new stellar binaries, and a triple
system. We infer that the frequency of 0.012-0.072M☉ brown
dwarfs in 28-1590AU orbits around young solar analogs is
3.2+3.1-2.7% (2σ limits). The result demonstrates that the
deficiency of substellar companions at wide orbital separations from
Sun-like stars is less pronounced than in the radial velocity "brown
dwarf desert." We infer that the mass distribution of companions in
28-1590AU orbits around solar-mass stars follows a continuous
dN/dM2∝M-0.42 relation over the 0.01-1.0M☉
secondary mass range. While this functional form is similar to that
for isolated objects less than 0.1M☉, over the entire
0.01-1.0M☉ range, the mass functions of companions and of
isolated objects differ significantly. Based on this conclusion and on
similar results from other direct imaging and radial velocity
companion surveys in the literature, we argue that the companion mass
function follows the same universal form over the entire range between
0 and 1590AU in orbital semimajor axis and ∼0.01-20M☉ in
companion mass. In this context, the relative dearth of substellar
versus stellar secondaries at all orbital separations arises naturally
from the inferred form of the companion mass function.
Description:
A complete description of the observing strategy of our AO survey was
given in Metchev & Hillenbrand (2004ApJ...617.1330M 2004ApJ...617.1330M) and in Metchev
(2006PhDT.........1M 2006PhDT.........1M). The full sample of 266 stars was observed in
the near-IR (NIR) with AO at the Palomar and Keck II telescopes on 47
clear nights over the course of three years: between 2002 January 31
and 2005 January 24. Additional astrometric follow-up was obtained
during 2006 and 2007 in a few individual cases.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 100 Deep sample
table2.dat 114 166 Shallow sample
table6.dat 68 217 Deep sample observations and sensitivity limits
table7.dat 68 252 Shallow sample observations and sensitivity limits
table8.dat 109 196 Candidate companions in the deep sample
table9.dat 114 91 Candidate companions in the shallow sample
table11.dat 76 76 New and confirmed secondaries
refs.dat 72 17 References for tables 8,9, 11
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2009)
J/A+A/356/141 : BV photometry for components of HIP doubles (Fabricius+ 2000)
J/A+A/341/121 : Visual binary orbits and masses (Soederhjelm 1999)
J/A+A/323/139 : K magnitude of Pleiades low-mass binaries (Bouvier+ 1997)
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Star name (G1)
23- 24 I2 h RAh Hour of Right Ascension (J2000)
26- 27 I2 min RAm Minute of Right Ascension (J2000)
29- 33 F5.2 s RAs Second of Right Ascension (J2000)
35 A1 --- DE- Sign of the Declination (J2000)
36- 37 I2 deg DEd Degree of Declination (J2000)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000)
42- 46 F5.2 arcsec DEs Arcsecond of Declination (J2000)
48- 53 F6.1 mas/yr pmRA Proper motion in Right Ascension
55- 58 F4.1 mas/yr e_pmRA Uncertainty in pmRA
60- 65 F6.1 mas/yr pmDE Proper motion in Declination
67- 70 F4.1 mas/yr e_pmDE Uncertainty in pmDE
72- 76 F5.1 pc Dist Heliocentric distance
78- 81 F4.1 pc e_Dist Uncertainty in Dist
83- 85 F3.1 mag Ksmag The KS band magnitude
87- 94 A8 --- SpType Adopted spectral type
96-105 A10 --- Assoc Name of association
107-110 F4.1 [yr] logA Log of the estimated age
112-114 F3.1 solMass Mass Estimated mass (1)
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Note (1): From the evolutionary tracks of
Baraffe et al. (1998, Cat. J/A+A/337/403 for M<1.4M☉ and age <30Myr),
D'Antona & Mazzitelli (1994ApJS...90..467D 1994ApJS...90..467D, for M>1.4M☉
and age <30Myr), and
Swenson et al. (1994ApJ...422L..79S 1994ApJ...422L..79S, for age >30Myr).
The mass estimates have been corrected for binarity.
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Byte-by-byte Description of file: table[67].dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Star name (G1)
23- 33 A11 "YYYY/MMM/DD" Date Date of observation
35- 41 A7 --- Obs Observatory
43- 48 A6 --- Optic Optic code (1)
50- 53 F4.1 mag 0.5Ksmag ? Limiting KS band magnitude at 0.5" (2)
55- 58 F4.1 mag 1Ksmag ? Limiting KS band magnitude at 1" (2)
60- 63 F4.1 mag 2Ksmag ? Limiting KS band magnitude at 2" (2)
65- 68 F4.1 mag 5Ksmag ? Limiting KS band magnitude at 5" (2)
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Note (1): Optic code is:
Corona = coronagraph was used.
ND1 = ND 1% filter was used at Palomar.
Note (2): The limiting magnitude corresponds to the apparent KS-band
magnitude of the faintest detectable point source at the given angular
separation, and is quoted only for the epoch of the deepest
observation. 0.5Ks magnitude for Table 7 only.
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Byte-by-byte Description of file: table[89].dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Primary star name (G1)
23- 24 I2 --- m_Name Companion number
26- 31 F6.3 arcsec rho Angular separation
33- 37 F5.3 arcsec e_rho Uncertainty in rho
39- 44 F6.2 deg PA Position angle
46- 49 F4.2 deg e_PA Uncertainty in PA
51- 55 F5.2 mag DelK Primary/Companion KS band magnitude
difference
57- 60 F4.2 mag e_DelK Uncertainty in DelK
62- 66 F5.2 mag Ksmag The KS band magnitude
68- 71 F4.2 mag e_Ksmag Uncertainty in Ksmag
73- 77 F5.2 mag J-Ks ? The (J-KS) color (1)
79- 82 F4.2 mag e_J-Ks ? Uncertainty in J-Ks
84- 93 A10 "YYYY/MM/DD" Date Date candidate companion discovered
95 A1 --- Tel [PK] Telescope used at discovery (2)
97-102 A6 --- phys Physical association of candidate companion
with primary (3)
104 A1 --- f_phys [d] Flag for ScoPMS 214 (4)
106-114 A9 --- Ref Reference if companion was already known.
See refs.dat file
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Note (1): For objects with obtained J-band data.
Note (2): P = Palomar; K = Keck.
Note (3): Various physical association codes as follows:
yes = bona fide companions
no = non-physical companions
? = undecided candidate companions
a = determined through astrometry from the present survey only
c = determined from their near-IR colors
p = determined from combining the present astrometry with prior astrometry
from the literature;
e = based on a non-point-like extended point-spread function (PSF);
Note (4):
d = Candidate companion 1 to ScoPMS 214 shares the proper motion
of the primary, but is inferred to be an unaffiliated field
object based on its K band spectrum (see Section 6.3).
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Name Primary name (G1)
22 A1 --- m_Name [BC] Suffix for companion
24- 28 F5.2 mag KMAG Absolute KS band magnitude
30- 33 F4.2 mag e_KMAG Uncertainty in KMAG
35- 39 F5.2 arcsec ASep Projected angular separation
41- 46 F6.2 AU PSep Projected physical separation
48- 51 F4.2 solMass M2 Secondary mass
53- 56 F4.2 --- q Mass ratio
58 A1 --- f_q [d] Flag on q (1)
60- 65 A6 --- Sample Sample (2)
67- 76 A10 --- Ref Reference in refs.dat file
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Note (1): "AD" denotes companions to stars in the 128-star minimally biased
AD sample (Section 9.1.1). "AD30" marks the 30 companions to AD stars
that reside at projected separations between 0.55"-12.5".
Note (2):
d = The mass ratio for the more distant companion B in the triple system
HD 91962ABC is calculated as q=MB/(MA+MC).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ref Reference code
6- 29 A24 --- Aut Author's name(s)
31- 49 A19 --- BibCode Bibcode
51- 72 A22 --- Com Comment
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Global notes:
Note (G1): Target identifiers are from sources:
1RXS = ROSAT All-Sky Bright (Voges et al., 1999, Cat. IX/10) and Faint
Source Catalogs (Voges et al., 2000, Cat. IX/29);
2RE, RE = ROSAT (2RE) Source Catalog of extreme ultra-violet sources (Pye et
al., 1995, Cat. J/MNRAS/274/1165; Pounds et al., 1993,
Cat. J/MNRAS/260/77);
HE = α Persei member (Heckmann et al., 1956, Cat. J/AN/283/109
substitute "HE" with "Cl Melotte 20" for query in SIMBAD);
1E, 2E = Einstein satellite observations;
HD = Henry Draper Catalog (Cannon A.J. and Pickering E.C., 1918,
Cat. III/135);
HII = Pleiades member (Hertzspring, 1947AnLei..19a...1H 1947AnLei..19a...1H, substitute "HII"
with "Cl Melotte 22" for query in SIMBAD;
van Leeuwen et al., 1986A&AS...65..309V 1986A&AS...65..309V, insert Cl* Melotte 22 before
"Pels" for query in SIMBAD);
HIP = Hipparcos catalog (Perryman et al., 1997, Cat. I/239);
PZ99, ScoPMS = Upper Scorpius member (Preibisch & Zinnecker,
1999AJ....117.2381P 1999AJ....117.2381P, [PZ99] JHHMMSS.s-DDMMSS in SIMBAD;
Walter et al., 1994AJ....107..692W 1994AJ....107..692W);
RX = ROSAT satellite observations;
SAO = Smithsonian Astrophysical Observatory Star Catalog (Whipple,
1966, Cat. I/131);
vB = Hyades member (van Bueren, 1952BAN....11..385V 1952BAN....11..385V, substitute "vB" with
"Cl Melotte 25" for query in SIMBAD).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 13-Oct-2009