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Download the Poster Nature vs. Nurture: Idencal “Twin” Luminous Blue Variable Stars with Contrasng Nebulae Ryan M. Lau1, T. L. Herter1, M. R. Morris2, J. D. Adams1,3 1Cornell University; 2University of California Los Angeles; 3SOFIA-USRA SOFIA/FORCAST Observaons of the Pistol and LBV3 Nebulae Key Results Luminous Blue Variables (LBVs) in and near Massive Stellar Clusters at the Galac/c Center • We propose that the Pistol and LBV3 are idenHcal “twins” that exhibit contrasHng nebulae due to the external influence of their different 5 • LBVs exist in a very brief (< 10 yrs) evoluHonary phase environments nearing the end of their lifeHmes and are extremely rare. Only 1 ~ 10 have been confirmed within the Milky Way • The Pistol nebula is composed of very small, transiently heated grains ( < 60 Å) that are differenHally decelerated and spuaered due to the winds • Three LBVs are located in the vicinity of the Quintuplet Cluster from Wolf-Rayet Carbon (WC) stars in the Quintuplet Cluster to the north (QC) at the GalacHc Center, a site of recent massive star formaon: qF3622, the Pistol star3, and G0.120-0.0484 (LBV3) QC • We suggest that the LBV3 nebula has a grain composiHon similar to that of qF362 the non-spuaered region of the Pistol nebula and is freely expanding • We characterize the LBV nebulae surrounding the Pistol star and LBV3 to trace their evoluHon and study the influence of • Both Pistol and LBV3 nebulae share idenHcal dynamical Hmescales (~104 yrs), their different environments -3 Pistol mass-loss rates (~10 MSun/yr ), and gas-to-dust mass raos (~275) The Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) • Images of the Pistol nebula at 19, 31, and 37 μm were obtained using FORCAST5 on the 2.5 m Telescope aboard the Stratospheric Observatory for Infrared Astronomy (SOFIA) on LBV3 June 8, 2011 (aliHtude ~ 43,000 q) 1 pc • Follow-up observaons with FORCAST of both the Pistol and 25 (blue), 31 (green), and 37 (red) μm LBV3 nebulae were obtained on July 1, 2013 (alHtude ~ 39,000 q) at 19, 25, 31, and 37 μm Lau et al. (2014) FORCAST (w/ elmo) on SOFIA SOFIA in flight, courtesy of NASA Pistol Nebula LBV3 Nebula Morphology: Ionizaon and Dust Energe/cs: Morphology: Ionizaon and Dust Energe/cs: • Shell-like with a radius of 0.5 • Pistol star does not provide enough • Shell-like with a radius of 0.7 pc • LBV3 does not provide enough Lyman- – 0.7 pc Lyman-conHnuum photons to ionize conHnuum photons to ionize nebula nebula • Circularly symmetric about LBV3 • Compressed and asymmetric • Externally ionized by Arches Cluster and about Pistol star • Externally ionized by Quintuplet Cluster • Freely expanding into possibly the Quintuplet Cluster surrounding medium • Shaped by Wolf-Rayet Carbon 1 pc • Dust heang dominated externally by 1 pc • Dust heang dominated centrally by (WC) star winds at the north 31 μm Flux with P-α Contours6 Quintuplet Cluster 31 μm Flux with P-α Contours6 LBV3 Dust Properes: Observed Pistol Nebula SED Dust Properes: Observed LBV3 Nebula SED • Composed of silicates with a minimum size 2 ¥ 1016 • Composed of silicates with minimum 1 ¥ 1016 M = 15 +0.009 of 10 Å and maximum sizes 25 – 60 Å 1 ¥ 1016 d 0.03 Mü grain size < 600 Å and maximum size 5 ¥ 10 Md = 0.021-0.003 Mü decreasing from south to north due to 40 – 2800 Å 15 L spuaering from WC star winds L 5 ¥ 10 1 ¥ 1015 5 Hz Hz 15 • Td ~ 95 K, Md ~ 0.02 MSun, and LIR ~ 10 LSun 14 ¥ ¥ 2 ¥ 10 5 ¥ 10 • Td ~ 120 K, Md ~ 0.03 MSun, Jy Jy 5 15 +46 H and LIR ~ 5 x 10 LSun H 1 ¥ 10 • Gas-to-dust mass rao of 276 95 & n − n 14 F 14 F 1 ¥ 10 n 5 ¥ 10 n +46 dQC = 2 pc 13 • Gas-to-dust mass rao of 275 69 • If LBV3 has very small, transiently heated 5 ¥ 10 + + − a = 10 fi a = 2800 fi a = 600 fi ¥ 14 min,SG +1 grains it would not be detectable by max min 2 10 a = +4 a- = 40 fi a- = 10 fi • If the Pistol nebula has a separate max,SG 34-6 fi Spitzer/IRAC min min 1 ¥ 1014 1 ¥ 1013 distribuHon of large grains (~1000 Å) it 5 10 15 20 25 30 35 40 5 10 15 20 25 30 35 40 would only be 20% of the total dust mass Wavelength mm Lau et al. (2014) SEDs modeled with DustEM8 Wavelength mm Lau et al. (2014) Formalism adopted EvoluHon of the LBV Nebulae H L H L from Kochanek (2011) Pistol Nebula Summary of Pistol and LBV3 Nebulae Proper/es LBV enters an Forms a 7000K Dust condenses and Pistol encounters d (pc) T (K) L (L ) L (L )4 M /M erupve state “pseudo photosphere” grows collisionally WC star winds to d IR Sun * Sun g d 5 6 the north Pistol 1.2 – 1.4 120 5 x 10 3.3 x 10 ~275 LBV3 1.4 95 ~105 4 x 106 ~275 Acknowledgements: We would like to thank the rest of the FORCAST team, George Gull, JusHn Schoenwald, Chuck Henderson, and Jason Wang, the USRA Science and Mission Ops teams, and the enHre SOFIA staff. This work is based on observaons made with the NASA/DLR Stratospheric Observatory for Infrared LBV3 freely LBV3 Nebula Astronomy (SOFIA). expands References: 1. Clark, J. S., Larionov, V. M., & Arkharov, A. 2005, A&A, 435, 239 2. Figer, D. F., McLean, I. S., & Morris, M. 1995, ApJ, 447, L29 3. Figer, D. F., Morris, M., Geballe, T. R., et al. 1999 ApJ, 525, 759 The mass-loss rate is 4. Mauerhan, J. C., Morris, M. R., Cotera, A., et al. 2010, ApJ, 713, L33 The opHcally thick dense winds The opHcally thick winds shield the 5. Adams, J. D., Herter, T. L., Gull, G. E., et al. 2010, Proc. SPIE, 7735, 62 greatly enhanced from form a “pseudo photosphere” dust formaon region (r ~ 1015 cm) 6. Wang, Q. D., Dong, H., Cotera, A., et al. 2010, MNRAS, 402, 895 -5 ~10 MSun/yr (quiescent) to with an apparent temperature from UV photons that would 7. Lau, R. M., Herter, T. L., Morris, M. R., Adams, J. D., ApJ, submiaed ~10-3 M /yr (erup6on) 8. Compiegne, M. Verstraete, L., Jones, A., et al. 2011, A&A, 525, A103 Sun cooler than that of the star otherwise sublimate the grains 9. Kochanek, C. S. 2011, ApJ, 743, 73 .
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