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FIELD BLUE STRAGGLERS AND RELATED MASS TRANSFER ISSUES. like this. George Preston, ESO, Santiago, 2012. or this. We stand on the shoulders of giants who pioneered stellar structure and evolution in interacting binaries. my giants. O. Struve. Z. Kopal. H. Bondi. G. P. Kuiper.

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  1. FIELD BLUE STRAGGLERS AND RELATED MASS TRANSFER ISSUES like this George Preston, ESO, Santiago, 2012

  2. or this

  3. We stand on the shoulders of giants who pioneered stellar structure and evolution in interacting binaries

  4. my giants O. Struve Z. Kopal H. Bondi G. P. Kuiper W. H. McCrea F. Hoyle R. Kippenhahn L. Lucy B. Paczynski

  5. my giants mentor O. Struve Z. Kopal H. Bondi G. P. Kuiper mentor W. H. McCrea F. Hoyle R. Kippenhahn friend friend L. Lucy B. Paczynski

  6. my giants Detached Semi-detached Contact gas streams Beta Lyrae O. Struve Z. Kopal Roche lobe overflow Mass transfer Bondi-Hoyle accretion H. Bondi G. P. Kuiper The BS mass-transfer model W. H. McCrea Hoyle-Bondi accretion Cases A B & C F. Hoyle R. Kippenhahn The most camera-shy giant known The Algol paradox & more L. Lucy B. Paczynski

  7. M3, where it all started M3

  8. In a dense stellar environment Allan Sandage PhD thesis

  9. . unlike my FBS domain .

  10. . mostly empty space . like here and here etc.

  11. While reading papers on the subject of my talk, I was surprised to learn …

  12. how often first-class astronomers ignore each other’s work! Thus, Sandage (AJ 1953) first identified blue stragglers unambiguosly in M3 McCrea invented an explanation for Sandage’s blue stragglers 11 years later (MNRAS 1964) with no reference to Sandage. Böhm-Vitense (ApJ 1980) confirmed operation of McCrea’s process 16 years later in the ζ Capricorni system with no reference to either Sandage or McCrea. McClure (ApJ 1984) brilliantly generalized Böhm-Vitense’s result 4 years later with no reference to Sandage or McCrea or Böhm-Vitense.

  13. how often first-class astronomers ignore each other’s work! Thus, Sandage (AJ 1953) first identified blue stragglers unambiguosly in M3 McCrea invented an explanation for Sandage’s blue stragglers 11 years later (MNRAS 1964) with no reference to Sandage. Böhm-Vitense (ApJ 1980) confirmed operation of McCrea’s process 16 years later in the ζ Capricorni system with no reference to Sandage or McCrea. McClure (ApJ 1984) brilliantly generalized Böhm-Vitense’s result 4 years later with no reference to Sandage or McCrea or Böhm-Vitense. Three decades of ignoring! WTF!

  14. Finally, in 1989 Peter Leonard set the stage for this conference AJ 98, 217

  15. HOW TO IDENTIFY FBS

  16. Of necessity, in the field we first identified metal-poor FBS by colorimetry.

  17. Of necessity, in the field we first identified metal-poor FBS by colorimetry. Any photometric system with a uv filter will work. Metal poor stars near GC turnoff BMPstars MS [Fe/H = 1 BHB RHB MS [Fe/H] = 0 W. W. Morgan would have called the BMP stars a “natural group”. HK Survey: Beers et al. 1985, 1992 Preston et al. 1994

  18. Of necessity, in the field we first identified metal-poor FBS by colorimetry. Any photometric system with a uv filter will work. FBS are a subset of BMP Metal poor stars near GC turnoff BMPstars MS [Fe/H = 1 BHB RHB MS [Fe/H] = 0 W. W. Morgan would have called the BMP stars a “natural group”. HK Survey: Beers et al. 1985, 1992 Preston et al. 1994

  19. In BMP domain isochrones with a wide range of ages and metallicities overlap in a tangled mess. main sequence isochrones Turnoffs for: [Fe/H] = 2.2 ages 3 7,10 Gy Isochrones of various [Fe/H] values and ages overlap in a 2-color diagram of the BS domain. subgiant isochrones Hence, “straggle” RYI Isochrones Green et al. (1987) Preston & Sneden 2000

  20. Thecool (red) edgeof the BS domain in any stellar system is defined by stars that are not members of the domain STRANGE DEFINITION Mandushev, Fahlman, Richer 1997, AJ

  21. MOST FBS ARE A SUBSET OF A LARGER FAMILY OF MAIN SEQUENCE MASS TRANSFER BINARIES Use of MSTO color as a boundary obscures this reality Mandushev, Fahlman, Richer 1997, AJ

  22. CASE IN POINT Metal-poor carbon stars below MSTO in hierarchical triples Masseron et al. 2012, ApJ, 751:14 surely FBS 12 Gy isochrone CS 22964-161 CS 22949-008 pri. & sec. mass transfer sequence = CEMP, literature

  23. Various tools have been devised to isolate field blue stragglers. Pier (1983) pioneered the identification of FBSs. FBS 0.2 D(0.2) BHB

  24. Various tools have been devised to isolate field blue stragglers. Sersic (b,c) Balmer parameters do this particularly well. They do not require knowledge of photometric colors. FBS BHB Clewley et al. 2002

  25. Various tools have been devised to isolate field blue stragglers. Sersic (b,c) Balmer parameters do this particularly well. They do not require knowledge of photometric colors. FBS BHB Clewley et al. 2002

  26. An application of Sersic parameters to Sloan data in the distant halo (n = many) (n = 4985) Xue et al. 2011

  27. Globular clusters provide luminosity calibration for Galactic structure applications, e.g. halo (R) Sarajedini 1993, ASP Conf. Ser.

  28. Globular clusters provide luminosity calibration for Galactic structure applications, e.g. halo (R) (MV) ~ 0.5 mag/star (distance) ~ 3 %/100 stars Sarajedini 1993, ASP Conf. Ser.

  29. GROUP PROPERTIES OF FBS

  30. It is easy to find binaries among FBS candidates JD - 2400000 RV-constant stars Binary stars A child can do it.

  31. Ahigh %of FBS are members of spectroscopic binaries 4 km/s vertical scales are not uniform 20 km/s Preston & Sneden 2000

  32. Ahigh %of FBS are members of spectroscopic binaries Very high Preston & Sneden 2000, AJ

  33. But alow %of FBS are indouble-linedspectroscopic binaries Very low ≤ The one DLSB, CS 22873-139, included here is contested by Spite et al. 2000, A&A, 360, 1077 Preston & Sneden 2000, AJ

  34. FBS have longish orbital periods & a high % of small orbital eccentricities reminiscent of their carbon-star cousins Normal MS binaries disk = x halo = o BMP blue metal-poor deficit of short periods excess of low eccentricities at P > 100 d C, s-process rich Preston & Sneden 2000, AJ

  35. and their mass functions suggest companions of lower-than-normal mass(like maybewhite dwarfs?). f1 = K13 P / (2 π G) = M23 (sin3 i) / (M1 + M2)2 FBS Ba, CH cousins Preston & Sneden 2000, AJ

  36. All of the preceding: High binary fraction Deficit of short periods Low orbital eccentricities Small mass functions No visible secondaries * And Thank You, Erika, for  Capricorni tell us that FBS are a species sui generis *Hierarchical triples excepted

  37. white dwarf flux red wing of L in white dwarf

  38. All of the preceding: High binary fraction Deficit of short periods Low orbital eccentricities Small mass functions Few (no?) visible secondaries And Thank You, Erika, for  Capricorni tell us that FBS are a species sui generis My perspective: Wide binary disruption is main reason for the specific frequency deficit In GCs relative to the Galactic field

  39. Specific frequency of FBS appears to be the upper bound of a sequence defined by OCs (DeMarchi et al 2006) and GCs (Piotto et al 2004) FBS This is a logarithm FBS 4.0 Something like “concentration” must be what matters This isn’t Preston & Sneden 2000, AJ

  40. These more frequent wide binaries are largely disrupted in GCs.Hence, the relatively low specific frequency of blue stragglers in globular clusters. This interpretation follows from the presumption that the Duquennoy-Mayor (1991, A&A) period distribution is universal. Ockham’s Razor, etc radial velocity binaries P<4000 d visual binaries c.p.m. binaries { William of Ockham 1248-1307 This 13% of radial velocity binaries with P  5 d merge in less than a Hubble time (Vilhu, 1982, A&A, 109, 17). Hence, the deficit of short period binaries in the field.

  41. DUSTING

  42. DUST: A thin layer that you notice on tables just before your guests arrive How do you hide it?

  43. DUST: A thin layer that you notice on tables just before your guests arrive In the house use this

  44. DUST: A thin layer that you notice on tables just before your guests arrive In stars redistribute by thermohaline mixing.

  45. Reconciliation of theory and observation Observational facts/issues that can be improved: Numbers, orbital parameters of MS and post-MS C and Ba stars Detection criteria Detection threshholds, bias, completeness Observer persistence (RV) Theory: Mass transfer by winds Including stuff like Davies-Pringle (1980) paradox AGB theory and practice from Busso & Gallinoand Convective envelopes Gravitational settling and stabilizing molecular gradients Dilution with and without thermohaline mixing those all those other Italians

  46. Do all MS CEMP survive the RGB ascent? INNOCENT QUESTION: Is the observed density ratio (RGB)/(MS) OK? IF LRGB /LMS ~ 40 Volume ratio ~ 250 and n(RGB)/n(MS) ~ 102 THEN Vol* n ~ 2.5 CEMP(RGB) MS RGB those CEMP(MS) n= nuclear time scale (kpc-3) = space density all relative volumes searched (in apparent magnitude limited surveys)

  47. All the stars with “no-dilution” solutions lie near MSTO; ~half are FBS) x pure AGB dilutions from Bisterzo et al. 2012, MNRAS, 422, 849 dilution = log MCE/MAGBacc Stars with “no-dilution” solutions MSTO dilution those all those RGB(CEMP)/MS(CEMP) ~ 2.5 in Bisterzo et al. sample. I was a bit surprised.

  48. We have very little information about wind accretion at large distances from an AGB donor. [s]

  49. Regression below is anchored by two long-period SLSBs with primaries originally classified as ordinary GK giants! [s] G8 III K0 III Griffin 1985

  50. Regression below is anchored by two long-period SLSBs with primaries originally classified as ordinary GK giants! Want more candidates? See McWilliam 1990, ApJS, 74 23/671= 4% of GK giants V(mag)  6.0, [s] > 0.2 Expect 800 more in HD (V<11) [s] G8 III K0 III Griffin 1985

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