![Harvey Richer
Large Hubble Space Telescope Programs
(PI H. Richer)
Cycle Star Cluster Distance [Fe/H] Orbits
9 Messier 4 2.2 kpc -1.2 123
13 NGC 6397 2.3 kpc -2 126
17 47 Tuc 4.5 kpc -0.7 121
Bold Scientific Leadership](https://image.slidesharecdn.com/richeruniversekaliraiifmrpublic-190522231519/85/Jason-Kalirai-Redefining-the-Initial-Final-Mass-Relation-3-320.jpg)
![Harvey Richer
Advocate for Canada’s
Scientific Leadership
Champion and Mentor of
Early Career Scientists
Large Hubble Space Telescope Programs
(PI H. Richer)
Cycle Star Cluster Distance [Fe/H] Orbits
9 Messier 4 2.2 kpc -1.2 123
13 NGC 6397 2.3 kpc -2 126
17 47 Tuc 4.5 kpc -0.7 121
Bold Scientific Leadership
FRIENDSHIP](https://image.slidesharecdn.com/richeruniversekaliraiifmrpublic-190522231519/85/Jason-Kalirai-Redefining-the-Initial-Final-Mass-Relation-4-320.jpg)
Jason Kalirai: Redefining the Initial-Final Mass Relation*
- 1. Redefining the Initial Final Mass Relation Jason Kalirai (JHU APL)
- 2. Redefining the Initial Final Mass Relation Jason Kalirai (JHU APL)
- 3. Harvey Richer Large Hubble Space Telescope Programs (PI H. Richer) Cycle Star Cluster Distance [Fe/H] Orbits 9 Messier 4 2.2 kpc -1.2 123 13 NGC 6397 2.3 kpc -2 126 17 47 Tuc 4.5 kpc -0.7 121 Bold Scientific Leadership
- 4. Harvey Richer Advocate for Canada’s Scientific Leadership Champion and Mentor of Early Career Scientists Large Hubble Space Telescope Programs (PI H. Richer) Cycle Star Cluster Distance [Fe/H] Orbits 9 Messier 4 2.2 kpc -1.2 123 13 NGC 6397 2.3 kpc -2 126 17 47 Tuc 4.5 kpc -0.7 121 Bold Scientific Leadership FRIENDSHIP
- 5. The Stellar Initial Mass Function and its Dependency on Environment Our Research Program 3 Key Ingredients to Bridge Stars and Galaxies Kalirai et al. (2013) High Precision Color Magnitude Relations Kalirai et al. (2012) Kalirai et al. (2009; 2014) Cummings et al. (2016; 2018) Mass Loss and Evolutionary Timescales
- 6. Why White Dwarfs? Unique White Dwarf Characteristics White dwarfs are the evolutionary end state for >95% of all stars - Contain the imprinted signature of rapid RGB/AGB evolutionary processes - Used to infer stellar mass loss rates - Assess contribution to galactic mass budget - Determine primordial mass functions for first generation populations White dwarfs have no nuclear fuel and therefore cool predictably with time - Serve as cosmic clocks to date ancient populations - Used to infer early Milky Way archaeology White dwarfs are supported by degenerate electron pressure - Serve as natural condensed matter laboratories for extreme stellar structure studies - Unique insights on stellar thresholds and pulsations through seismology White dwarfs have (mostly) simple H atmospheres - Spectroscopical determination of fundamental properties without knowing their distances White dwarfs are among the faintest stars in the Universe - Increased contrast to detect planets and measure the composition of planetary debris
- 7. Why White Dwarfs? Unique White Dwarf Characteristics White dwarfs are the evolutionary end state for >95% of all stars - Contain the imprinted signature of rapid RGB/AGB evolutionary processes - Used to infer stellar mass loss rates - Assess contribution to galactic mass budget - Determine primordial mass functions for first generation populations White dwarfs have no nuclear fuel and therefore cool predictably with time - Serve as cosmic clocks to date ancient populations - Used to infer early Milky Way archaeology White dwarfs are supported by degenerate electron pressure - Serve as natural condensed matter laboratories for extreme stellar structure studies - Unique insights on stellar thresholds and pulsations through seismology White dwarfs have (mostly) simple H atmospheres - Spectroscopical determination of fundamental properties without knowing their distances White dwarfs are among the faintest stars in the Universe - Increased contrast to detect planets and measure the composition of planetary debris
- 8. Log(g) = 7.0 P.-E. Tremblay & P. Bergeron, priv comm The Tell Tale Signature of a White Dwarf
- 9. Log(g) = 7.0, 8.0 The Tell Tale Signature of a White Dwarf P.-E. Tremblay & P. Bergeron, priv comm
- 10. Log(g) = 7.0, 8.0, 9.0 The Tell Tale Signature of a White Dwarf P.-E. Tremblay & P. Bergeron, priv comm
- 11. The Trick Simultaneously measure both the initial and final masses of stars The Method - Cheating Past the Hard Stuff The Initial-Final Mass Relation (IFMR)
- 12. When we started… The Initial-Final Mass Relation (IFMR)
- 13. 3 Step Roadmap to Measure the IFMR Photometric Survey Uncover white dwarfs in clusters and measure cluster ages and turnoff masses
- 14. 3 Step Roadmap to Measure the IFMR Photometric Survey Uncover white dwarfs in clusters and measure cluster ages and turnoff masses Spectroscopic Survey Confirm remnants and measure final (white dwarf) properties (age, mass)
- 15. 3 Step Roadmap to Measure the IFMR Photometric Survey Uncover white dwarfs in clusters and measure cluster ages and turnoff masses Spectroscopic Survey Confirm remnants and measure final (white dwarf) properties (age, mass) Initial-Final Mass Relation TCLUSTER - TWHITE DWARF = TPROGENITOR
- 16. Finding White Dwarfs in Star Clusters Kalirai et al. (2001a; 2001b; 2001c) Kalirai et al. (2003) Kalirai & Tosi (2004) Kalirai et al. (2007) Kalirai et al. (2008) Kalirai et a. (2009) M4
- 17. Bright White Dwarfs in the Globular Cluster M4 Kalirai et al. (2009; 2012)
- 18. Summary of Initial-Final Mass Relation 1.) Low mass stars like the Sun will lose 46% of their mass through stellar evolution 2.) Intermediate mass stars with MINITIAL = 2-3 MSUN will lose 70-75% of their mass 3.) Higher mass stars with MINITIAL = 5-6 MSUN will lose 80% of their mass 4.) Scatter in the relation is mostly due to observational errors The Initial-Final Mass Relation Weidemann (1977, 1987, 2000) Reimers & Koester (1980’s) Claver et al. (2001) Dobbie et al. (2004, 2006) Williams et al. (2004, 2007) Liebert et al. (2005) Kalirai et al. (2005a, 2005b) Kalirai et al. (2005a, 2005b) Kalirai et al. (2007, 2008, 2009) Cummings et al. (2015) Cummings et al. (2016a; 2016b) Cummings et al. (2018a; 2018b) 1.26 MSUN
- 19. The Critical Mass b/w White Dwarfs and Supernovae An Important Threshold in Astrophysics Sets the number of core-collapse supernovae occurring in the Universe Sets the level of energetic feedback in galaxies Sets the formation rate of neutron stars (especially ones with low-velocity kicks) Sets the nucleosynthetic yields and chemical enrichment from higher mass stars Shapes the metallicity, star formation rate, and morphology of galaxies Methods Difficult to constrain theoretically due to unconstrained physical effects - mass loss, overshooting, binary interactions, rotationally induced mixing - end product could be a massive electron-degenerate white dwarf or an electron capture SNe Difficult to constraint observationally due to the IMF and short evolutionary times Indirect methods - Fit stellar models to red supergiants in pre-images of SNe (e.g., Smartt 2009) - Measure the SFH of a galaxy in the vicinity of a supernovae (e.g., Williams et al. 2018) Results indicate MCRIT = 7 to <9.5 MSUN
- 20. The Initial-Final Mass Relation Properties of Planetary Nebulae (Ciardullo 2010) Characterize Exoplanet Hosts (Kilic, Gould, & Koester 2009) Measure SN Rates, Evolution, and Progenitors (Pritchet et al. 2008; Greggio 2010; Kistler et al. 2011) Constrain Star Formation Scenarios (Leitner & Kravtsov 2011) Study Disk Formation in LCDM (Leitner & Kravtsov 2011) Calculate Stellar IMF (Lockmann, Baumgardt, & Kroupa 2010)
- 21. Thank you, and Happy Birthday!