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Jason Kalirai (Hubble Fellow - UC Santa Cruz)

Stellar Remnants as Cosmological Probes. Space Telescope Science Institute. Feb 11 th , 2008. Jason Kalirai (Hubble Fellow - UC Santa Cruz). Collaborators: UMontreal - P. Bergeron UCLA - B. Hansen, D. Reitzel, R. M. Rich OCIW - D. Kelson UBC - H. Richer …also, for NGC 6397

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Jason Kalirai (Hubble Fellow - UC Santa Cruz)

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  1. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Jason Kalirai (Hubble Fellow - UC Santa Cruz) Collaborators: UMontreal - P. Bergeron UCLA - B. Hansen, D. Reitzel, R. M. Rich OCIW - D. Kelson UBC - H. Richer …also, for NGC 6397 Jay Anderson (STScI), Ivan King (UW) James Brewer and Saul Davis (UBC) Gregory Fahlman and Peter Stetson (HIA/NRC) Michael Shara (AMNH) Jarrod Hurley (Swinburne)

  2. Maryland Primary (Feb 12th)!

  3. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Jason Kalirai (Hubble Fellow - UC Santa Cruz) Collaborators: UMontreal - P. Bergeron UCLA - B. Hansen, D. Reitzel, R. M. Rich OCIW - D. Kelson UBC - H. Richer …also, for NGC 6397 Jay Anderson (STScI), Ivan King (UW) James Brewer and Saul Davis (UBC) Gregory Fahlman and Peter Stetson (HIA/NRC) Michael Shara (AMNH) Jarrod Hurley (Swinburne)

  4. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Outline: 1.) What are white dwarfs and why should we study them? 2.) A new imaging survey for white dwarfs: The CFHT Open Cluster Survey. 3.) The initial-final mass relation. chemical evolution and enrichment of the ISM the age of the Galactic disk the age of the Galactic halo: HST studies of globular clusters 4.) Stellar mass loss as a function of environment. UV upturn in elliptical galaxies planets around white dwarfs type Ia SNe 5.) Serendipity. 6.) Other projects: Galaxy Formation, Structure, and Evolution.

  5. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 - Sirius: brightest star in the night sky (V = -1.5). - 1840’s - exhibits irregular motions on the sky (Bessel 1844). - Optical detection of companion by Alvan Clark in 1862.

  6. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 - 50 year binary orbit 1 Msun companion, but MV = 11.3 (0.003 Lsun)! - Sirius A and B have similar colors Radius of Sirius B = 1/100 Sirius A. - Adams (1914; 1925): spectrum is white, gravitational redshift measured. - White dwarf: very dense remnant of a hydrogen burning star (no fuel).

  7. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 A Few Reasons to Study White Dwarfs 1.) Over 97% of all stars will eventually form white dwarfs. Unique link to the distribution of first generation stars in old stellar populations. 2.) White dwarfs cool predictably with time use as chronometers. 3.) Upper mass limit to white dwarf production = lower limit to type II SNe. 4.) Constraining fundamental stellar evolution and stellar mass loss. 5.) Theoretical calibration of evolutionary models of AGB and PN phases.

  8. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The CFHT Open Star Cluster Survey (Kalirai et al. 2001, AJ, 122, 257) - Deep CFHT B,V imaging data set of two dozen, rich open clusters. Goals: 1.) Cluster ages, distances, reddening, richness, etc. 2.) Luminosity and mass functions. 3.) Test theoretical isochrones through numerical simulations. 4.) Catalogue large populations of white dwarfs in each system. Results - NGC 6819: Kalirai et al. (2001, AJ, 122, 267) - NGC 2099: Kalirai et al. (2001, AJ, 122, 3239) - NGC 2168 and NGC 2323: Kalirai et al. (2003, AJ, 126, 1402) - Numerical Simulations: Kalirai & Tosi (2004, MNRAS, 351, 649) - NGC 6791: Kalirai et al. (2007, ApJ, 671, 748) - NGC 7789: Kalirai et al. (2007, ApJ, in press, astro-ph/0706.3894) - data shared with many external groups…

  9. Stellar Remnants as Cosmological Probes West (1967) Mermilliod et al. (1996) Kalirai et al. (2001) Space Telescope Science Institute Feb 11th, 2008 NGC 2099 (M37) - Kalirai et al. (2001, AJ, 122, 3239)

  10. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Some CFHT CMDs

  11. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Kalirai et al. (2007, ApJ in press, astro-ph/0706.3894)

  12. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008

  13. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The Initial-Final Mass Relation Curves from: Marigo (2001, A&A, 370, 194) Girardi et al. (2000, A&AS, 141, 371) - Total integrated stellar mass loss through post main-sequence evolution. - High mass end: Upper mass limit to WD production. - Low mass end: Ages of the Galactic disk and halo, stellar IMF.

  14. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Some CFHT CMDs

  15. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Weidemann + Reimers & Koester (1980’s) Claver et al. (2001) Dobbie et al. (2004, 2006) Williams et al. (2004, 2007) Kalirai et al. (2005) Liebert et al. (2005)

  16. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Kalirai et al. (2007, ApJ in press, astro-ph/0706.3894) Conclusion:Mfinal = (0.109 +/- 0.007)Minitial + (0.394 +/- 0.025) Msun

  17. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The Age of the MW Disk White dwarf mass function: Liebert, Bergeron & Holberg (2005)

  18. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The Age of the MW Halo NGC 6397 126 HST/ACS orbits Kalirai et al. (2007, ApJL, 657, 93) Richer et al. (2006, Science, 313, 936) Hansen et al. (2007, ApJ, 671,380)

  19. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The Age of the MW Halo NGC 6397 126 HST/ACS orbits tNGC 6397 = 11.5 - 12.0 Gyrs tM4 = 10.1 - 12.5 Gyrs t47 Tuc = ??? Hansen et al. (2007, ApJ, 671, 380)

  20. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Hansen et al. (2007, ApJ, 671, 380)

  21. Stellar Remnants as Cosmological Probes = +3.56 +/- 0.04 mas/yr = -17.34 +/- 0.04 mas/yr Kalirai et al. (2007, ApJL, 657, 93) Space Telescope Science Institute Feb 11th, 2008 The Orbit of NGC 6397

  22. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 A Strange Cluster (N6791): Age = 8 -10 Gyrs but… [Fe/H] = +0.4 Kalirai et al. (2007, ApJ, 671, 748)

  23. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 MS turnoff age = 8 Gyrs WD cooling age = 2.4 Gyrs? Bedin et al. (2005, ApJL, 624, 45)

  24. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The Theory: - Mass Loss on the RGB (Faulkner 1972; Sweigart 1987, Castellani & Castellani 1993; Hansen 2005). Two Tests: 1.) RGB luminosity function. 2.) WD mass function. Kalirai et al. (2007, ApJ, 671, 748)

  25. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Forming He-core White Dwarfs Kalirai et al. (2007, ApJ, 671, 748)

  26. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Forming He-core White Dwarfs Bedin et al. (2008, ApJ, in press, astro-ph/0801.1346)

  27. Space Telescope Science Institute Feb 11th, 2008 Conclusions and Implications 1.) Mfinal = (0.109 +/- 0.007)Minitial + (0.394 +/- 0.025) Msun. 2.) Age of Galactic disk = 8 Gyr, Age of Galactic halo = 12 Gyr. 3.) Mass loss is more efficient in higher metallicity environments. 4.) NGC 6791 stars evolved along three channels…no age issue, 2nd peak. 5.) Source of UV upturn. -- variable excess among galaxies. -- correlation with metallicity? 6.) Planets. -- currently no known planets around WDs. -- Fischer & Valenti (2005) - 25% MS stars with planets have [Fe/H] > +0.3 - 3% of MS stars with planets have -0.5 < [Fe/H] < 0.0 7.) Type Ia SNe rates. 8.) Kilic, Stanek, & Pinsonneault (2007, ApJ, 671, 761). - Fraction of [Fe/H] > +0.3 stars in Solar nbhd in the past 10 Gyrs = 3%. - Single, low mass WD formation rate = 4%.

  28. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Gemini/GMOS HST/ACS

  29. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Kalirai et al. (2007, ApJ, submitted)

  30. Space Telescope Science Institute Feb 11th, 2008 The Andromeda Spiral Galaxy (M31) The Andromeda Team (UCSC): Raja Guhathakurta, Karrie Gilbert, Evan Kirby, Kirsten Howley, Priya Kollipara, Jedidah Isler, Carynn Luine, Johnathan Rice, Andrew Fittingoff, Basilio Yniguez, Jennifer Consiglio Non-UCSC folks: UVa - Steve Majewski, Jamie Ostheimer, Ricky Patterson, & Rachael Beaton STScI - Tom Brown UMass - Mark Fardal UCLA - Michael Rich & David Reitzel Arizona - Michael Cooper Yale - Marla Geha UC Irvine - James Bullock Wesleyan - Andreea Font Columbia - Kathryn Johnston

  31. Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo SPLASH a

  32. Size of M31’s Stellar Halo Size of M31’s Stellar Halo Image Credit: GALEX team, Caltech, NASA Image Credit: GALEX team, Caltech, NASA Background Image of Night Sky from Stellarium Planetarium Background Image of Night Sky from Stellarium Planetarium Background Image of Night Sky from Stellarium Planetarium

  33. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) - Hubble Space Telescope WFPC2 - STScI-PRC03-21

  34. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) - Hubble Space Telescope WFPC2 - STScI-PRC03-21

  35. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Weidemann + Reimers & Koester (1980’s) Claver et al. (2001) Dobbie et al. (2004, 2006) Williams et al. (2004, 2007) Kalirai et al. (2005) Liebert et al. (2005)

  36. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Kalirai et al. (2007, ApJ in press, astro-ph/0706.3894)

  37. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Signature of a White Dwarf:

  38. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 The White Dwarf Cooling Age of NGC 6397: Hansen et al. (2007, ApJ submitted, astro-ph/0701738)

  39. Stellar Remnants as Cosmological Probes Space Telescope Science Institute Feb 11th, 2008 Peeling off the Luminosity Function Kalirai et al. (2007, ApJ, 671, 748)

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