1. Wide Binaries: the non-violent end of the semi-major axis distribution
Julio Chanamé
Hubble Fellows Symposium 2010

2. Massive Black Holes and Galactic Globular Clusters
Wide Binaries: the non-violent end of
the semi-major axis distribution
Massive Black Holes and
Stellar Dynamics in
Galactic Globular Clusters
2011
Symposium
Julio Chanamé
Hubble Fellows Symposium 2010

3. Wide Binaries: the non-violent end of the semi-major axis distribution
stellar masses, radii
distance scale
chemical evolution
CVs, novae, supernovae
GRBs ….
Duquennoy & Mayor (1991)

4. Wide Binaries: the non-violent end of the semi-major axis distribution
stellar masses, radii
distance scale
chemical evolution
CVs, novae, supernovae
GRBs ….
40 AU
103 AU
2104 AU
wide binaries
a = AU
P ~ 105 yr
m = 2 M
vorb  1 km/s
Duquennoy & Mayor (1991)

5. Wide Binaries: the non-violent end of the semi-major axis distribution
Importance of studying wide binaries
Identifying wide binaries: methods and catalogs
3. Formation and evolution of wide binaries
stellar parameters for field stars
star formation
dynamics and Galactic astronomy

6. Parallax-based distances to low-mass field stars
NLTT + Hipparcos
LSPM-N + Hipparcos
Gould & Chanamé (2004)
Lépine & Bongiorno (2007)

7. White dwarfs in wide binaries
Monteiro et al. (2006)
Initial-to-final mass relation
stellar parameteres: M, Z, redshift, radial velocity
age metallicity relation for Galactic disk
WD luminosity function and age of Galactic disk
initial-final mass relations for WDs
empirical constraints on mass loss
age-activity relations for low-mass stars
…..
Catalán et al. (2008)

8. Subsample of halo binaries with Hipparcos components
Galactic Astronomy
Subsample of halo binaries
with Hipparcos components
halo
disk
secondaries
primaries
Silvestri et al. (2001)
Chanamé & Ivans (in prep.)

9. Galactic Astronomy halo disk Silvestri et al. (2001)
Chanamé & Ivans (in prep.)

10. Constraints on star formation theories
White & Ghez (2001)
Clarke (1995)
disk instabilities
capture
core fragmentation
“coevality” of binary components
favors fragmentation rather
than formation in isolation!!
Larson (2001)

11.  Wide binaries as dynamical probes   M a   , E  0 m a b v Gm
binding energy  E  -
Wide binaries as
dynamical probes 2a
a   , E  0 m  a  b  v M

12.  Wide binaries as dynamical probes   M a   , E  0 m a b v Gm
binding energy  E  -
Wide binaries as
dynamical probes 2a
a   , E  0 m  1)
b >> a  a  2)
condition for destruction:
3) closest encounter: b  v M

13.  ¡ ! Wide binaries as dynamical probes   M a   , E  0 m a b v Gm
binding energy  E  -
Wide binaries as
dynamical probes 2a
a   , E  0 m  1)
b >> a  a  2)
condition for destruction:
3) closest encounter: b ! - 4)  v M

14. 1985: constraints on the nature of (disk) dark matter
Bahcall, Hut, & Tremaine (1985)
MDT < 2 M

15. Constraints on the nature of halo dark matter
Kouwenhoven et al. (2010)
Yoo, Chanamé, & Gould (2004)
PAH: Poveda, Allen, & Hernández (2007)
LB: Lépine & Bongiorno (2007)
CRC: Close, Richer, & Crabtree (1990)
CG: Chanamé & Gould (2004)

16. Wide Binaries: the non-violent end of the semi-major axis distribution
Importance of studying wide binaries
Identifying wide binaries: methods and catalogs
3. Formation and evolution of wide binaries
stellar parameters for field stars
star formation
dynamics and Galactic astronomy

17. Wide Binaries: the non-violent end of the semi-major axis distribution
# of binaries
Heggie
Bahcall & Soneira ………………………19
Retterer & King ………………………... 11
Latham et al. ……………………………. 6
Bahcall, Hut, & Tremaine
Weinberg, Shapiro, & Wasserman
Close, Richer, & Crabtree ……………… 39
Wasserman & Weinberg ……………….. 9
Gould, Bahcall, & Maoz ……………….. 13 ………………… HST
Chanamé & Gould …………………… ……….... NLTT + 2MASS + USNO-A
Yoo, Chanamé, & Gould
Lépine & Bongiorno ………………… ……..……… LSPM + Hipparcos
Sesar, Ivezić, & Jurić …………….… > ………..…... SDSS + USNO-B
Quinn et al.
Jiang & Tremaine
Longhitano & Binggeli ……………… > …………..…… SDSS
Dhital et al. ………………………… ……………… SDSS + USNO-B

18. Wide Binaries: the non-violent end of the semi-major axis distribution
# of binaries
Heggie
Bahcall & Soneira ………………………19
Retterer & King ………………………... 11
Latham et al. ……………………………. 6
Bahcall, Hut, & Tremaine
Weinberg, Shapiro, & Wasserman
Close, Richer, & Crabtree ……………… 39
Wasserman & Weinberg ……………….. 9
Gould, Bahcall, & Maoz ……………….. 13 ………………… HST
Chanamé & Gould …………………… ……….... NLTT + 2MASS + USNO-A
Yoo, Chanamé, & Gould
Lépine & Bongiorno ………………… ……..……… LSPM + Hipparcos
Sesar, Ivezić, & Jurić …………….… > ………..…... SDSS + USNO-B
Quinn et al.
Jiang & Tremaine
Longhitano & Binggeli ……………… > …………..…… SDSS
Dhital et al. ………………………… ……………… SDSS + USNO-B

19. Close pairs on the sky SDSS Sesar, Ivezić, & Jurić (2008) 8  V  12
random
8  V  12
12  V  16

20. Close pairs on the sky Two-point angular correlation function w()
Longhitano & Bingelli (2010)
SDSS data
f() ~ -

21. 1  2
Common proper-motion systems
1950
a  100 AU
2000

22. Luyten (1945-1980)  > 0.18 arcsec/yr NLTT “Reduced Proper Motion”
RPM = V + 5 log() ~ MV
“Reduced Proper Motion” diagram
NLTT

23. Luyten (1945-1980)  > 0.18 arcsec/yr USNO (1950-2000) BV (plates)
“Reduced Proper Motion”
(1998) JHK (CCD)
2MASS
RPM = V + 5 log() ~ MV
“Reduced Proper Motion” diagram
NLTT
rNLTT
Salim & Gould (2003)

24. rNLTT wide binaries final catalog: 1147 systems 999 genuine pairs
801 disk binaries
116 halo binaries
82 with WD components
Chanamé & Gould (2004)

25. rNLTT wide binaries final catalog: 1147 systems 999 genuine pairs
801 disk binaries
116 halo binaries
82 with WD components
Chanamé & Gould (2004)

26. SDSS color-mag relations!
Proper motions precise distance information
SDSS color-mag relations!
Sesar, Ivezić, & Jurić (2008)

27. Proper motions + precise distance information
Dhital et al. (2010)
50"
high mass ratio
twins
WDs / subdwarfs

28. Wide Binaries: the non-violent end of the semi-major axis distribution
Importance of studying wide binaries
Identifying wide binaries: methods and catalogs
3. Formation and evolution of wide binaries
stellar parameters for field stars
star formation
dynamics and Galactic astronomy

29. Formation of wide binaries
clustered star formation?
dynamical capture in the field?

30. Formation of wide binaries
formation during the
dissolution phase of
star clusters
clustered star formation?
dynamical capture in the field?
Kouwenhoven et al. (2010)

31. giant molecular clouds
Formation of wide binaries
formation during the
dissolution phase of
star clusters
clustered star formation?
dynamical capture in the field?
Kouwenhoven et al. (2010)
Galactic Open Clusters
open clusters are
destroyed by
giant molecular clouds
(Binney & Tremaine,
Sec.7.2)
Wielen (1971)
age

32. Formation of wide binaries
formation during the
dissolution phase of
star clusters
clustered star formation?
dynamical capture in the field?
Kouwenhoven et al. (2010)
The Medea/Saturn evolutionary scenario
Galactic Open Clusters
Wielen (1971)
age
Delacroix (1862)
Goya (1820)

33. Initial distribution of semi-major axes
star forming regions
Orion Nebula Cluster
Age ~1 Myr
2 Myr
5 Myr
f(a) ~ 1/a
Kraus & Hillenbrand (2009)
Poveda & Allen (2004)

34. Today’s distribution of
semi-major axes
SDSS disk binaries!!
effect of giant molecular clouds
Weinberg, Shapiro, & Wasserman (1987)
Wasserman & Weinberg (1991)
Jiang & Tremaine (2009)
Sesar, Ivezić, & Jurić (2008)

35. ...however, we have systems much wider than 0.1 pc !!!
Chanamé & Gould (2004)
0.1 pc

36. ...however, we have systems much wider than 0.1 pc !!!
Chanamé & Gould (2004)
bmin ≥ at
M ≥ 103 M
excluded
allowed
0.1 pc
Since binaries with large semimajor axes, a  0.1 pc, are more easily disrupted than those with small ones, any deviation (or lack thereof) from a power-law distribution at wide separations provides a test of halo dark matter models.

37. closest encounter is the all encounters are equally important
bmin >> a  “tidal limit”
bmin << a  “Coulomb limit”
closest encounter is the
most important one
all encounters are equally important

38. bmin >> a  “tidal limit” bmin << a  “Coulomb limit”
Bahcall, Hut, & Tremaine (1985)

39. Constraining Halo Dark Matter
Monte Carlo Simulations
simple impulse approximation
no disk or Galactic tides
constant density of perturbers
combinations of (M,ρ) of MACHOs

40. Constraining Halo Dark Matter
Monte Carlo Simulations
simple impulse approximation
no disk or Galactic tides
constant density of perturbers
combinations of (M,ρ) of MACHOs
Yoo, Chanamé, & Gould (2004)

41. Constraining Halo Dark Matter
Monte Carlo Simulations
simple impulse approximation
no disk or Galactic tides
constant density of perturbers
combinations of (M,ρ) of MACHOs
Yoo, Chanamé, & Gould (2004)

42. Constraining Halo Dark Matter
Monte Carlo Simulations
simple impulse approximation
no disk or Galactic tides
constant density of perturbers
combinations of (M,ρ) of MACHOs
Yoo, Chanamé, & Gould (2004)

43. Constraining Halo Dark Matter
Chanamé & Gould (2004)
Yoo, Chanamé, & Gould (2004)
Halo wide binaries exclude MACHOs with M > 43 M at the standard local halo density ρH at the 95% confidence level (2σ)

44. Constraining Halo Dark Matter
Quinn et al. (2009)

45. Constraining Halo Dark Matter
Chanamé & Gould (2004)
Quinn et al. (2009)

46. Constraining Halo Dark Matter
Quinn et al. (2009)
Yoo, Chanamé, & Gould (2004)

47. Constraining Halo Dark Matter
larger samples of halo binaries
understanding the genesis of halo wide binaries
more sophisticated modeling
Allen, Poveda, & Hernández-Alcántara (2007)
Quinn & Smith (2009)
  binaries

48. SDSS + USNO-B   4 mas/yr DR7 + USNO-B ~ 3 106 halo stars

49. SDSS + USNO-B   4 mas/yr DR5 + USNO-B ~ 4 106 halo stars
+ distance information

50. Looking for wide binaries in SDSS
MDM 2.4m
Chanamé 2010 (in prep.)

51. Looking for wide binaries in SDSS
MDM 2.4m
Chanamé 2010 (in prep.)

52. Looking for wide binaries in SDSS
MDM 2.4m
Chanamé 2010 (in prep.)

53. Looking for wide binaries in SDSS
MDM 2.4m
V  20.5 mag / 20min exptime

54. SUMMARY
wide binaries are applicable to a large range of astronomical problems:
Galactic
structure &
evolution
fundamental
stellar parameters
tests of stellar
evolution
cosmological
interest
formation of wide binaries likely associated to (young) star cluster dissolution
detailed shape of semi-major axis distribution is of fundamental dynamical interest
large, clean samples of wide binaries are thus much welcomed (Gaia, LSST, …)
more sophisticated modeling will also be required