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MAGNETIC FIELDS IN BRIGHT-RIMMED CLOUDS AND COMETARY GLOBULES TRACED USING R-BAND POLARIZATION OBSERVATIONS

  • SOAM, ARCHANA (Aryabhatta Research Institute of Observational Sciences (ARIES)) ;
  • GOPINATHAN, MAHESWAR (Aryabhatta Research Institute of Observational Sciences (ARIES)) ;
  • LEE, CHANG WON (Korea Astronomy and Space Science Institute) ;
  • BHATT, HRISH (Indian Institute of Astrophysics, Kormangala (IIA))
  • Received : 2014.11.30
  • Accepted : 2015.06.30
  • Published : 2015.09.30

Abstract

We present results of our R-band polarimetry of a bright-rimmed cloud, IC1396A (with BRC 36), associated with the H II region S131 and the cometary globule LDN 1616 to study their magnetic field geometry. The distances of these clouds have been reported to be ~ 750 pc and ~ 450 pc, respectively in the literature. The young open cluster Trumpler 37 in the vicinity of IC1396A and the high mass stars in the Orion belt near L1616 are found to be responsible for the structure of these clouds. We made polarimetry of foreground stars inferred from their distances measured by the Hipparcos satellite to subtract the foreground contribution to the observed polarization results. We discuss the optical polarimetric results and compare our findings with MHD simulations towards BRCs and CGs.

Keywords

References

  1. Bertoldi, F., 1989, The Photoevaporation of Interstellar clouds. I - Radiation-Driven Implosion, ApJ, 346, 735 https://doi.org/10.1086/168055
  2. Garcia-Segura, G. & Franco, J., 1996, From Ultracompact to Extended H II Regions, ApJ, 469, 171 https://doi.org/10.1086/177769
  3. Giuliani Jr., J. L., 1979, The Hydrodynamic Stability of Ionization-Shock Fronts - Linear Theory, ApJ, 233, 280 https://doi.org/10.1086/157389
  4. Goodman, A. A., Jones, T. J., Lada, E. A., & Myers, P. C., 1995, Does Near-Infrared Polarimetry Reveal the Mag-netic Field in Cold Dark Clouds?, ApJ, 448, 748 https://doi.org/10.1086/176003
  5. Goodman, A. A., 1996, The Interpretation of Polarization Position Angle Measurements, ASPC, 97, 325
  6. Henney, W. J., Arthur, S. J., de Colle, F., & Mellema, G., 2009, Radiation-Magnetohydrodynamic Simulations of the Photoionization of Magnetized Globules, MNRAS, 398, 157 https://doi.org/10.1111/j.1365-2966.2009.15153.x
  7. Mackey, J., & Lim, A. J., 2011, Effects of Magnetic Fields on Photoionized Pillars and Globules, MNRAS, 412, 2079 https://doi.org/10.1111/j.1365-2966.2010.18043.x
  8. Rautela, B. S., Joshi, G. C., & Pandey, J. C., 2004, ARIES Imaging Polarimeter, BASI, 32, 159
  9. Reipurth, B., 1983, Star formation in BOK Globules and Low-Mass Clouds. I - The Cometary Globules in the GUM Nebula, A&A,117,183
  10. Soam, A., Maheswar, G., Bhatt, H. C., Lee, C. W., & Ramaprakash, A. N., 2013, Magnetic Fields in Cometary Globules - IV. LBN 437, MNRAS, 432, 1502 https://doi.org/10.1093/mnras/stt576
  11. Williams, R. J. R., 1999, Shadowing Instabilities of Ioniza tion Fronts, MNRAS, 310, 789 https://doi.org/10.1046/j.1365-8711.1999.03014.x
  12. Williams R. J. R., 2007, Photoionized Flows from Magnetized Globules, Ap&SS,307,179 https://doi.org/10.1007/s10509-006-9257-y