1 / 14

Stellar evolution and the ‘O-rich AGB sequence’

Stellar evolution and the ‘O-rich AGB sequence’. F. Jiménez-Esteban 1,2 , P. García-Lario 2 & D. Engels 1. 1- Hamburger Sterwarte / Universit ät Hamburg 2- ISO Data Center / European Space Astronomy Center. van der Veen & Habing, 1988, A&A, 194, 125.

corbin
Download Presentation

Stellar evolution and the ‘O-rich AGB sequence’

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Stellar evolution and the ‘O-rich AGB sequence’ F. Jiménez-Esteban1,2, P. García-Lario2 & D. Engels1 1- Hamburger Sterwarte / Universität Hamburg 2- ISO Data Center / European Space Astronomy Center

  2. van der Veen & Habing, 1988, A&A, 194, 125 Stellar evolution and the ‘O-rich AGB sequence’ The ‘O-rich AGB sequence’ Well defined location of O-rich AGB stars in the IRAS c-c diagram Sequence of increasing optical thickness of the CSE: 3 possible interpretations: - Evolutionary - Progenitor mass - Combination of both AGB PN Thinner Bluer Thicker Redder

  3. Stellar evolution and the ‘O-rich AGB sequence’ The sample Two previous photometric analysis of OH/IR stars: I - Arecibo sample - 363 (Jiménez-Esteban et al., 2005, A&A, 431, 779) II - GLMP sample - 94 (Jiménez-Esteban et al., 2005, A&A, submitted) 457 OH/IR stars providing very good coverage • Samples are not directly comparable, but complementary: i) Arecibo: blue colours GLMP: red colours ii) Arecibo: Arecibo sky GLMP: the entire sky (32% of GLMP in the GB)

  4. Stellar evolution and the ‘O-rich AGB sequence’ Bolometric Flux • Well coveredSpectral Energy Distribution J-H-K ( own obs. or 2MASS ); A-C-D-E( MSX ); 12-25-60-100 ( IRAS ) (1.25 - 1.65 - 2.2 m ) (8.28 - 12.13 - 14.65 - 21.3 m ) • Integration: trapezium rule + Extrapolation Fbol

  5. We assume LOH/IR 3500 L Distance & Galactic Height Stellar evolution and the ‘O-rich AGB sequence’ Absolute bolometric luminosity 41 GLMP OH/IR in the direction of the Galactic Bulge D  8kpc Wide range  2500 – 26000 L Maximum in  3500 L Coincidence with other authors who studied mainly bluer samples of OH/IR stars in the GB and in the solar neighborhood ( Habing et al. 1985; Rowan-Robinson & Chester 1987; Jones et al. 1994; Blommaert et al. 1998; Wood et al. 1998; Jackson et al. 2002; Knauer et al. 2001 ) The luminosity function may be similar throughout the Galaxy and not very dependent on the colours

  6. Stellar evolution and the ‘O-rich AGB sequence’ Parametrization [12] –[25] adequate descriptor for the blue part of the sequence [25] –[60] adequate descriptor for the red part of the sequence We parameterize the curve: Lower λ Bluer Higher λ Redder

  7. Stellar evolution and the ‘O-rich AGB sequence’ Galactic Height Relation between  and the galactic height red OH/IR stars are concentrated towards the Galactic Plane The red part of the O-rich AGB sequence must be populated mainly with objects of higher mass

  8. Stellar evolution and the ‘O-rich AGB sequence’ Expansion velocity Deficit of OH/IR stars with high vexp at large GH Systematic trend: high vexp in OH/IR stars with small GH Low vexp associated to low  High  associated to high vexp Low  OH/IR stars covers the whole range of vexp The red part of the O-rich AGB sequence is mainly populated by high progenitor mass and high Vexp stars The blue part of the O-rich AGB sequence is populated by OH/IR stars with a wide range of Vexp and progenitor masses

  9. Stellar evolution and the ‘O-rich AGB sequence’ Evolutionary Scenario Evolutionary Scenario All OH/IR stars would start the AGB phase, independent of their progenitor mass, in the blue part of the O-rich AGB sequence, and then they would evolve toward redder colors, although only the more massive stars would reach the red end of the O-rich AGB sequence.

  10. Thin CSE Thin & Thick CSE Thick CSE Stellar evolution and the ‘O-rich AGB sequence’ Galactic Scale Height ∆ = 0.3 Galactic scale height ( H ):

  11. Stellar evolution and the ‘O-rich AGB sequence’ Evolutionary connection • Extremely blue ( H = 536 pc ) Optical Miras with short-P ( H = 600 pc ) (Jura 1994) Type III PN ( <Z> = 660 pc ) (Maciel & Dutra 1992) • Blue ( H = 344 pc ) Solar neighbourhood OH/IR ( H = 330 pc ) (Ortiz & Maciel 1996) Miras close to the Galactic Plane ( H = 315 pc ) (Wood & Cahn 1977) Type II PN ( <Z> = 350 pc ) (Maciel & Dutra 1992)

  12. Stellar evolution and the ‘O-rich AGB sequence’ Evolutionary connection • Transition ( H = 287 pc ) Intermediate- and long-P Miras ( H = 240 pc ) (Jura & Kleinmann 1992) Optical C-rich stars ( H = 290 - 260 pc ) (Groenewegen et al. 1992) ( Massive ) Type II PN ( 250 < <Z> < 350 pc ) • Red ( H = 193 pc ) IR C-stars ( H = 155-200 pc ) • (Groenewegen et al. 1992; Claussen et al. 1996) • O-rich HBB AGB stars (N-rich) Type I PN ( <Z> = 150 pc ) • (Maciel & Dutra 1992) • Extremely red ( H = 48 pc ) Infrared PN? ( OHPNe )

  13. Stellar evolution and the ‘O-rich AGB sequence’ Conclusions Unique sample of ~450 OH/IR to study the O-rich AGB sequence Found a triple relation among Progenitor mass -  - vexp Postulated an evolutionary scenario which need to be further investigated Defined 5 main groups and established evolutionary connections between all kind of AGB stars and PNe

  14. Stellar evolution and the ‘O-rich AGB sequence’

More Related