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Emission-line stars and HII-Galaxies

Emission-line stars and HII-Galaxies. Alexei Kniazev (SAAO, SALT). 6 November 2012. SALT Proposals:. 1. Optical Spectroscopy of Stars With 24 Micron Shells: Search for New Luminous Blue Variables: 2010-1-RSA_OTH-001 + 2011-3-RSA_OTH-002

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Emission-line stars and HII-Galaxies

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  1. Emission-line stars and HII-Galaxies Alexei Kniazev (SAAO, SALT) 6 November 2012

  2. SALT Proposals: 1.Optical Spectroscopy of Stars With 24 Micron Shells: Search for New Luminous Blue Variables: 2010-1-RSA_OTH-001 + 2011-3-RSA_OTH-002 2.Planetary Nebulae in the area of CMa dwarf galaxy: 2011-3-RSA-003 3.The Eridanus void galaxies: census and evolutionary status 2012-1-RSA-001

  3. Search for new Luminous Blue Variables (1) Vasilii Gvaramadze (SAI MSU) & Alexei Kniazev

  4. Search for new Luminous Blue Variables (2) Altogether 35 different candidates were observed with different quality

  5. Search for new Luminous Blue Variables (3) Gvaramadze, Kniazev et al. 2012,MNRAS,421,3325

  6. Search for new Luminous Blue Variables (4) Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres

  7. Search for new Luminous Blue Variables (5) The PoWR code solves the non-LTE radiative transfer problem in a spherically expanding atmosphere simultaneously with the statistical equilibrium equations while accounting for energy conservation.

  8. Search for new Luminous Blue Variables (6) Todt , Kniazev, et al., 2012, MNRAS, submitted : In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48.

  9. The PNe in the area of CMa dwarf galaxy (1)

  10. The PNe in the area of CMa dwarf galaxy (2) From the total sample of 39 PNe and PNe candidates, 18 were observed up to now using SALT and 1.9m SAAO telescopes.

  11. The PNe in the area of CMa dwarf galaxy (3) From the total sample of 39 PNe and PNe candidates, 18 were observed up to now using SALT and 1.9m SAAO telescopes.

  12. The PNe in the area of CMa dwarf galaxy (4) Pilot results on observations of first 7 PNe are published in Kniazev (2012, in press)

  13. The PNe in the area of CMa dwarf galaxy (5)

  14. Galaxy evolution versus global environment • Role of denser galaxy density is relatively clear, but for very low density regions (voids) the effect of environment is poorly known. • Voidsare delineated byluminous (L > L*) massive objects, are populatedby dwarfs and devoid of luminous objects. Void properties can vary. • Not only galaxy interactionsoccur in voids much less frequently, but also DM halo and galaxy formation from density perturbations can be somewhat retarded due to the lower voidmean gravitational potential.

  15. The void galaxies: census and evolutionary status • The basic relation “O/H vs M_B” as derived on the Local Volume groups and field dwarfs (van Zee & Haynes 2006, the upper dashed line) and O/H, observed in void dwarfs • The line shifted by 1 mag (or ~0.15 dex on O/H) better accounts for possible systematic lower O/H in the void • Several extremely low O/H dwarfs: very rare special cases From Pustilnik, Teplyakova & Kniazev (2011)

  16. The Eridanus void galaxies: redshifts Three more galaxies in the Eridanus void out from 10 observed in 2012-1 300s exposure for each

  17. The Eridanus void galaxies: abundances Three galaxies in the Eridanus void out of 4 observed in 2012-1 shows [O III] 4363 line.

  18. The Eridanus void galaxies: census and evolutionary status

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