2007A&A...464..581K


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.14CEST14:01:23

2007A&A...464..581K - Astronomy and Astrophysics, volume 464, 581-599 (2007/3-3)

A brown dwarf desert for intermediate mass stars in Scorpius OB2?

KOUWENHOVEN M.B.N., BROWN A.G.A. and KAPER L.

Abstract (from CDS):

We present JHKS observations of 22 intermediate-mass stars in the Scorpius-Centaurus OB association, obtained with the NAOS/CONICA system at the ESO Very Large Telescope. This survey was performed to determine the status of (sub)stellar candidate companions of Sco OB2 member stars of spectral type A and late-B. The distinction between companions and background stars is made on the basis of a comparison to isochrones and additional statistical arguments. We are sensitive to companions with an angular separation of 0.1''-11'' (13-1430AU) and the detection limit is KS=17mag. We detect 62 stellar components of which 18 turn out to be physical companions, 11 candidate companions, and 33 background stars. Three of the 18 confirmed companions were previously undocumented as such. The companion masses are in the range 0.03M≤M≤1.19M, corresponding to mass ratios 0.06≤q≤0.55. We include in our sample a subset of 9 targets with multi-color ADONIS observations from Kouwenhoven et al. (2005A&A...430..137K). In the ADONIS survey secondaries with KS<12mag were classified as companions; those with KS>12mag as background stars. The multi-color analysis in this paper demonstrates that the simple KS=12mag criterion correctly classifies the secondaries in ∼80% of the cases. We reanalyse the total sample (i.e. NAOS/CONICA and ADONIS) and conclude that of the 176 secondaries, 25 are physical companions, 55 are candidate companions, and 96 are background stars. Although we are sensitive (and complete) to brown dwarf companions as faint as KS=14mag in the semi-major axis range 130-520AU, we detect only one, corresponding to a brown dwarf companion fraction of 0.5±0.5% (M>30MJ). However, the number of brown dwarfs is consistent with an extrapolation of the (stellar) companion mass distribution into the brown dwarf regime. This indicates that the physical mechanism for the formation of brown dwarf companions around intermediate mass stars is similar to that of stellar companions, and that the embryo ejection mechanism does not need to be invoked in order to explain the small number of brown dwarf companions among intermediate mass stars in the Sco OB2 association.

Abstract Copyright:

Journal keyword(s): binaries: visual - binaries: general - stars: formation - stars: low mass, brown dwarfs - clusters open and associations: individual: Sco OB2

VizieR on-line data: <Available at CDS (J/A+A/464/581): table2.dat table4.dat tablea1.dat tablea2.dat tablea3.dat>

Simbad objects: 84

goto Full paper

goto View the reference in ADS

Number of rows : 84

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 Ass Ori OB 2 As* 05 31 26.000 +12 09 36.00           ~ 5 0
2 TYC 5478-859-1 * 09 48 56.4041736696 -10 30 32.386149806   12.79 11.70     ~ 6 0
3 CCDM J10191-6441AB ** 10 19 05.07255 -64 40 34.5275   5.72 5.67     A1V 47 1
4 HD 92896 * 10 41 59.65270 -63 30 26.2741   7.53 7.34     A3IV 29 1
5 HD 95324 ** 10 59 14.01166 -61 19 14.6584   6.118 6.178     B8IV 37 1
6 HD 101582 * 11 41 00.2287691962 -54 32 55.551918558   7.43 7.41     A0V 16 0
7 HD 104021 * 11 58 38.9317460548 -52 46 07.348097749   7.70 7.49     A7V 19 0
8 HD 104839 * 12 04 16.7045672461 -51 28 21.051575259   6.43 6.47     B9.5V 22 0
9 HD 105874 * 12 11 14.8132783939 -52 13 03.185465564   8.10 7.91     A6V 15 1
10 HD 106036 * 12 12 10.2739609068 -63 27 14.809116299   7.063 6.977     A2V 28 0
11 NAME Lower Centaurus Crux As* 12 19 -57.1           ~ 334 1
12 HD 107143 * 12 19 16.6043709690 -47 49 48.071668344   7.96 7.86     A1V 18 0
13 HD 108501 * 12 28 19.2607760520 -64 20 27.574132199 6.08 6.14 6.09     A0V 35 0
14 HD 109197 * 12 33 19.9292206160 -54 58 52.058020273   7.708 7.614     A2V 20 0
15 HD 109808 ** 12 38 07.25326 -55 55 52.3849           A1/2V 18 0
16 V* FH Mus El* 12 39 55.8513201361 -66 30 40.091455588   6.199 6.252     B8V 47 0
17 HD 110390 ** 12 42 27.2256910048 -61 01 06.688913161   7.35 7.20     A1V 24 0
18 HD 110461 * 12 42 49.7638510107 -55 56 49.285412751   6.029 6.057     B9V 36 0
19 HD 110698 ** 12 44 34.9624673 -57 17 12.920403   6.710 6.641     A0IV/V 24 1
20 V* V823 Cen a2* 12 56 58.2221359148 -54 35 14.487809249   6.431 6.485     ApSiCr 63 0
21 HD 114772 ** 13 13 23.35287 -50 41 59.3747   5.886 5.899     B9.5V 43 1
22 HD 115988 * 13 21 25.9078344885 -43 38 03.579384898   6.647 6.662     B9V 22 0
23 HD 117193 * 13 29 36.1666726943 -47 52 32.950557529   7.01 6.93     A1V 16 0
24 HD 119884 ** 13 47 10.5582709469 -52 16 09.313314097   6.949 6.930     A0V 18 0
25 HD 121040 * 13 54 38.3015968448 -55 44 17.992320393   7.53 7.24     A9V 32 0
26 HD 121336 ** 13 56 19.96521 -54 07 56.7142   8.96 8.69 7.52   A1V 40 0
27 HD 122259 * 14 01 45.7042537675 -39 26 19.007351452   7.70 7.54     A3IV/V 18 0
28 HD 122982 * 14 06 08.2356097459 -44 41 20.711153799   7.24 7.23     A0V 19 0
29 HD 123445 * 14 08 51.8859074874 -43 28 14.801932182   6.11 6.17     B9V 56 0
30 HD 124620 * 14 16 31.9635295806 -57 17 50.986561286   7.38 7.18     B9IV 16 0
31 HD 127215 * 14 31 14.3793856953 -40 39 21.349094592   7.62 7.47     A1V 20 0
32 HD 128819 * 14 40 17.6464592221 -40 50 30.052649830   6.580 6.649     B8/9V 32 1
33 V* IT Lup a2* 14 40 19.2712157079 -45 47 37.826912719   6.504 6.615     ApSi 52 0
34 HD 131399 ** 14 54 25.30919 -34 08 34.0412   7.19 7.08 8.33   A1V 33 0
35 HD 131461 ** 14 54 54.47833 -36 25 49.2930   7.3 7.23     A0/1V 18 1
36 GSPC S273-E * 14 56 52.0 -44 49 15           ~ 15 0
37 V* HZ Lup a2* 15 06 33.1977060064 -30 55 06.536906644   5.893 5.977     ApSi 95 0
38 V* HR Lup a2* 15 08 12.1245697358 -40 35 02.158712447 5.25 5.65 5.79     B8IVSi 146 1
39 HD 134837 * 15 13 07.6613057814 -36 05 29.114095971   5.996 6.079     B8V 40 1
40 HD 136164 * 15 20 13.3925969213 -34 55 31.571564890   7.97 7.76     A2V 21 0
41 HD 136347 ** 15 21 30.09403 -38 13 07.2862   6.480 6.538     ApSi 60 1
42 NAME Upper Centaurus Lupus As* 15 24 -41.9           ~ 342 1
43 HD 137919 ** 15 30 21.29078 -41 55 08.4957           B9.5V 24 0
44 HD 138138 ** 15 31 17.20862 -33 49 11.4308           A2/3V 37 0
45 HD 138221 * 15 31 50.2299849204 -32 52 52.013844928   6.540 6.488     B7V 36 0
46 HD 138343 * 15 32 10.3300687362 -21 58 00.560013162   7.26 7.23     B9V 24 0
47 HD 140817 ** 15 47 04.4641248452 -35 30 37.226520746   6.89 6.92     A0V 40 1
48 HD 140840 * 15 47 06.1670334211 -35 31 04.938686406   7.26 7.26     B9/A0V 27 0
49 HD 142315 SB* 15 54 41.5960624501 -22 45 58.512729751   6.887 6.861     B9V 94 0
50 * 47 Lib * 15 55 00.36549 -19 22 58.5127   5.930 5.957     B2/3V 109 0
51 HD 143567 * 16 01 55.4546289923 -21 58 49.397570493   7.27 7.19 7.87   B9V 94 1
52 V* LM Lup a2* 16 04 44.4890499672 -39 26 04.780382706   6.86 6.94   6.968 ApSiCr 57 1
53 HD 144175 * 16 05 19.1476601945 -23 40 08.829045668   7.70 7.64     B9V 30 0
54 HD 144254 ** 16 05 43.3891779201 -21 50 19.540607253   7.96 7.78     A0V 28 0
55 HD 144118 * 16 05 46.27839 -39 50 35.9336   8.14 7.96     A5V 18 1
56 HD 144569 ** 16 07 04.6738866107 -16 56 35.755722772   8.06 7.90     B9.5V 27 0
57 HD 145145 * 16 07 08.1659909266 +49 04 59.121008585   7.88 7.60     A2 9 0
58 HD 144586 * 16 07 14.9288660424 -17 56 09.736020891   7.91 7.81     B9V 30 0
59 BD-14 4350 PM* 16 07 15.2714663900 -14 23 35.212241832   11.82 10.65     ~ 10 0
60 HD 144844 V* 16 08 43.7199351602 -23 41 07.451972503 5.59 5.90 5.88     B9V 132 0
61 HD 144925 ** 16 09 02.6012201339 -18 59 44.039571243   7.98 7.78     A0V 38 1
62 HD 144981 ** 16 09 20.8883510830 -19 27 25.958998409   8.22 8.04     A0V 40 0
63 HD 145189 ** 16 10 25.3553081546 -23 06 23.387071540   8.00 7.79     A3III/IV 25 0
64 NAME Upper Sco Association As* 16 12 -23.4           ~ 955 1
65 HD 145554 * 16 12 21.8333006041 -19 34 44.570507060   7.77 7.64     B9V 69 0
66 HD 145792 a2* 16 13 45.49839 -24 25 19.5421           B6IV 105 0
67 HD 145880 * 16 14 57.7662971068 -39 37 40.122795395   7.18 7.16     B9.5V 24 0
68 NAME ASSOC II SCO As* 16 15 -24.2           ~ 1077 1
69 HD 146285 * 16 16 25.1727655978 -24 59 19.465473164   8.12 7.94     B8V 56 0
70 HD 146331 * 16 16 50.6247453979 -25 51 46.704565035   8.69 8.30     B9V 27 0
71 HD 147001 V* 16 21 27.0324154185 -48 11 19.043359873   6.456 6.498     B7V 25 0
72 HD 147432 * 16 22 51.77663 -23 07 07.5271   7.93 7.79     A1III/IV 30 1
73 HD 147553 ** 16 23 56.71426 -33 11 57.8305   6.47 6.46     B9.5V(n)+A1V(n) 45 1
74 HD 147701 * 16 24 21.3184734300 -25 01 31.448891118 9.66 9.74 9.20     B5III 104 0
75 HD 147809 ** 16 24 59.1476819338 -25 21 17.984250932   8.99 8.63     A1V 46 0
76 * rho Oph D ** 16 25 24.2937199705 -23 27 36.816821785 6.71 7.05 6.74     B3/4V 187 1
77 * rho Oph C * 16 25 35.0836168833 -23 24 18.788751256 7.24 7.59 7.27     B5V 101 0
78 HD 148562 TT* 16 29 54.5956585494 -24 58 46.075096179 8.08 7.99 7.81     A2V 49 0
79 HD 148716 * 16 31 11.0701008056 -29 59 52.419135469   8.93 8.53     F3V 30 0
80 HD 150193 Be* 16 40 17.9242900066 -23 53 45.192676418 9.69 9.32 8.79 8.41   B9.5Ve 284 0
81 HD 150645 * 16 44 21.0946513964 -44 22 43.477865487   8.19 7.94     A3V 14 0
82 HD 150742 * 16 44 42.5932088698 -40 50 22.829911792   5.528 5.628     B3V 62 1
83 HD 154117 * 17 04 27.8223079195 -23 23 25.935831562   8.09 7.09     G8/K0III 14 0
84 HD 154310 * 17 06 20.1896222098 -37 13 39.329253567   6.05 5.98     A2IV 23 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2007A&A...464..581K and select 'bookmark this link' or equivalent in the popup menu


2019.10.14-14:01:23

© Université de Strasbourg/CNRS

    • Contact