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Mining Hot, Luminous Stars in the Southern Sky: A New Look at the Magellanic-Cloud System

Mining Hot, Luminous Stars in the Southern Sky: A New Look at the Magellanic-Cloud System. Dana Casetti, Kathy Vieira, Terry Girard, Bill van Altena. Yale University and CIDA - Venezuela. Outline. New surveys Candidate Selection Spatial distribution: Bridge, Clouds ’ periphery, LA, MS

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Mining Hot, Luminous Stars in the Southern Sky: A New Look at the Magellanic-Cloud System

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  1. Mining Hot, Luminous Stars in the Southern Sky: A New Look at the Magellanic-Cloud System Dana Casetti, Kathy Vieira, Terry Girard, Bill van Altena Yale University and CIDA - Venezuela

  2. Outline • New surveys • Candidate Selection • Spatial distribution: Bridge, Clouds’ periphery, LA, MS • Formation insights

  3. Known Blue Stars in the Bridge Area Blue stars – Demers & Irwin 1991 (photographic photometry in 2 pairs of UK Schmidt plates; ~1700 stars to V =18.5) 2MASS M giants HI – Putman et al. 2003 MS

  4. New Surveys • GALEX (Bianchi et al. 2011) ~ all sky => NUV • 2MASS (Skrutskie et al. 2006) – all sky => J • SPM4 (Girard et al. 2011) – d < -20o => V, m • APASS (Henden et al. 2011) => V

  5. New Surveys: GALEX Data release 5 – Bianchi et al. 2011 - FUV 1344-1786Å, leff = 1538.6Å - NUV 1771-2831Å, leff = 2315.7Å - All-sky imaging survey(AIS) 65.3 million sources; limiting mags 19.9 FUV, 20.8 NUV - Medium-depth imaging survey (MIS) – 12.6 million sources; limiting mags 22.6 FUV, 22.7 NUV

  6. New Surveys: SPM4 -103 million objects; positions and absolute proper motions, B and V to V~ 17.5, d < -20o - Girard et al. 2011 CCD - PV Photographic (~1/3) 1st epoch only B, V ccd data are calibrated on Tycho2 V : 0.93x0.93deg; 0.83”/pix B : 0.42x0.42deg; 0.74”/pix ~20% coverage

  7. New Surveys: SPM4 Photometric properties: comparison with OGLE3 data in the LMC OGLE3 OGLE3 & SPM4 e V = 0.05 -0.07 mag

  8. New Surveys: APASS DR3 -The AAVSO all-sky photometric catalog (www.aavso.org/apass); Henden et al. 2009, 2010,2011; DR3 – 18.9 million obj. - In Johnson B, V and Sloan g,r,i; valid from V~10 to ~17.0 DR3 -From comparison with SPM4 (V mag only), there are some bad regions at dec < -80deg; eV ~ 0.06 - 0.07 mag.

  9. Area Coverage in the MC region 2MASS M giants HI – Putman et al. 2003 (outer contour: NHI = 1020 atoms/cm2) GALEX (No V) GALEX+SPM4_CCD GALEX+APASS+SPM4 MS

  10. Color Selection (NUV-V)0= [-2.0,2.0] (V-J)0 = [-1.2,-0.2] eNUV ≤ 0.10 eJ ≤ 0.15 E(B-V)≤ 0.5 B8 (NUV-V)0= [-2.0,0.0] (V-J)0 = [-1.2,-0.2] eNUV ≤ 0.10 eJ ≤ 0.15 E(B-V)≤ 0.5 B5

  11. Color Selection: Spatial Distribution (NUV-V)0= [-2.0,2.0] (V-J)0 = [-1.2,-0.2] eNUV ≤ 0.10 eJ ≤ 0.15 E(B-V)≤ 0.5

  12. Second Cut: V Magnitude (NUV-V)0= [-2.0,2.0] (V-J)0 = [-1.2,-0.2] eNUV ≤ 0.10 eJ ≤ 0.15 E(B-V)≤ 0.5 V0 = [13.0,17.0)

  13. Spatial Distribution vs (NUV-V) color (V-J)0 = [-1.2,-0.2]; eNUV ≤ 0.10; eJ ≤ 0.15, E(B-V)≤ 0.5; V0 = [13.0,17.0)

  14. Proper-motion Distribution vs (NUV-V) color (V-J)0 = [-1.2,-0.2]; eNUV ≤ 0.10; eJ ≤ 0.15, E(B-V)≤ 0.5; V0 = [13.0,17.0)

  15. Final Selection (NUV-V)0= [-2.0,0.0] (V-J)0 = [-1.2,-0.2] eNUV ≤ 0.10 eJ ≤ 0.15 E(B-V)≤ 0.5 V0 = [13.0,17.0) Dm ≤ 8.0 mas/yr em ≤ 4.0 mas/yr

  16. Spatial Distribution SPM4 proper motions 2MASS M giants OB cand. (567 all area) GALEX (No V) GALEX+SPM4_CCD GALEX+APASS+SPM4

  17. Spatial Distribution Vieira et al. 2010 proper motions 2MASS M giants OB cand. (567 all area) GALEX (No V) GALEX+SPM4_CCD GALEX+APASS+SPM4

  18. Spatial Distribution 2MASS M giants OB cand. HI – Putman et al. 2003 30 Dor

  19. Emission nebulae Associations Clusters 15 of 567/1445; 3 in the LMC 12 in the wing 71 of 567/3326; 2 in the SMC 11 in the LMC rest in the wing, bridge 10 of 567/3740; 1 in the SMC 2 in the LMC rest in the wing Bica et al. 2008 – catalog 567 OB cand. – this work

  20. Spatial Distribution: Zooming Out HI - Nidever et al. 2010 15.0 21.9 log NHI

  21. Spatial Distribution: Zooming Out HI - Nidever et al. 2010 15.0 21.9 log NHI

  22. Spatial Distribution: Zooming Out

  23. Recent Past of the Clouds Recent encounter -current separation: 24 kpc -errors from proper-motion errors only ----------------------------------------------------------------------------------- SF peaks (Glatt et al. 2010; cluster ages of young clusters < 1 Gyr)LMC (1193) SMC (324) 125 Myr 160 Myr 630 Myr 800 Myr ----------------------------------------------------------------------------- OB stars => 10-25 Myr (Demers&Batinelli98) => formed in situ

  24. The LMC’s present-day gaseous and young star distributions Bekki & Chiba 2007 -dynamical, hydrodynamical and SF history of the latest 0.8Gyr -outer parts of disks collide (key is the impact parameter, used 8 kpc) -assym. gas distrib. with lumps at the ends of the bar; one sp. arm connects to the bridge. stellar (age < 20 Myr) surface density gas surface density

  25. Summary - Stringently-selected OB-type candidates in the periphery of the Clouds, Bridge, LA and MS - Clumps at the ends of the bar in the LMC, and along a spiral arm - Well-populated SMC wing, with an extension all the way to the LMC halo; this extension appears offset from the HI high density region; two branches appear to partly surround the SMC - Some of the OB candidates are located in portions of the Leading Arm

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