DOI QR코드

DOI QR Code

STARS: A 3D GRID-BASED MONTE CARLO CODE FOR RADIATIVE TRANSFER THROUGH RAMAN AND RAYLEIGH SCATTERING WITH ATOMIC HYDROGEN

  • Chang, Seok-Jun (Department of Physics and Astronomy, Sejong University) ;
  • Lee, Hee-Won (Department of Physics and Astronomy, Sejong University)
  • Received : 2020.09.30
  • Accepted : 2020.12.05
  • Published : 2020.12.31

Abstract

Emission features formed through Raman scattering with atomic hydrogen provide unique and crucial information to probe the distribution and kinematics of a thick neutral region illuminated by a strong far-ultraviolet radiation source. We introduce a new 3-dimensional Monte-Carlo code in order to describe the radiative transfer of line photons that are subject to Raman and Rayleigh scattering with atomic hydrogen. In our Sejong Radiative Transfer through Raman and Rayleigh Scattering (STaRS) code, the position, direction, wavelength, and polarization of each photon is traced until escape. The thick neutral scattering region is divided into multiple cells with each cell being characterized by its velocity and density, which ensures flexibility of the code in analyzing Raman-scattered features formed in a neutral region with complicated kinematics and density distribution. To test the code, we revisit the formation of Balmer wings through Raman scattering of the far-UV continuum near Lyβ and Lyγ in a static neutral region. An additional check is made to investigate Raman scattering of O vi in an expanding neutral medium. We find a good agreement of our results with previous works, demonstrating the capability of dealing with radiative transfer modeling that can be applied to spectropolarimetric imaging observations of various objects including symbiotic stars, young planetary nebulae, and active galactic nuclei.

Keywords

Acknowledgement

This work was supported by the Korea Astronomy and Space Science Institute under the R&D program (Project No. 2018-1-860-00) super-vised by the Ministry of Science, ICT and Future Planning. This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT; No. NRF-2018R1D1A1B07043944). SJC is very grateful to Dr. Kwang-Il Seon for his help with the adoption of the grid-based technique.

References

  1. Ahn, S.-H., & Lee, H.-W. 2015, Polarization of Lyman α Emergent from a Thick Slab of Neutral Hydrogen, JKAS, 48, 195
  2. Akras, S., Guzman-Ramirez, L., Leal-Ferreira, M. L., & Ramos-Larios, G. 2019, A Census of Symbiotic Stars in the 2MASS, WISE, and Gaia Surveys, ApJS, 240, 21 https://doi.org/10.3847/1538-4365/aaf88c
  3. Angel, J. R. P. 1969, Polarization of Thermal X-Ray Sources, ApJ, 158, 219 https://doi.org/10.1086/150185
  4. Arrieta, A., & Torres-Peimbert, S. 2002, Broad Hα Wings in Young Planetary Nebulae RMxAC, 12, 154
  5. Bethe, H. A., & Salpeter, E. E. 1967, Quantum Mechanics of One and Two Electron Atoms (New York: Academic Press)
  6. Brinch, C., & Hogerheijde, M. R. 2010, LIME - A Flexible, Non-LTE Line Excitation and Radiation Transfer Method for Millimeter and Far-infrared wavelengths, A&A, 523, A25 https://doi.org/10.1051/0004-6361/201015333
  7. Birriel, J. J. 2004, Raman-scattered He ii at 4851 Å in the Symbiotic Stars HM Sagittae and V1016 Cygni, ApJ, 612, 1136 https://doi.org/10.1086/422835
  8. Celnikier, L. M., & Lefevre, J. 1974, Radiation Transport in Circumstellar Dust - A Monte Carlo Approach, A&A, 36, 429
  9. Chang, S.-J., Heo, J.-E., Di Mille, F., et al. 2015, Formation of Raman Scattering Wings around Hα, Hβ, and Paα in Active Galactic Nuclei, ApJ, 814, 98 https://doi.org/10.1088/0004-637X/814/2/98
  10. Chang, S.-J., Lee, H.-W., & Yang, Y. 2017, Polarization of Rayleigh Scattered Lyα in Active Galactic Nuclei, MN-RAS, 464, 5018 https://doi.org/10.1093/mnras/stw2744
  11. Chang, S.-J., Lee, H.-W., Lee, H.-G., et al. 2018, Broad Wings around Hα and Hβ in the Two S-type Symbiotic Stars Z Andromedae and AG Draconis, ApJ, 866, 129 https://doi.org/10.3847/1538-4357/aadf88
  12. Chen, Z., Frank, A., Blackman, E. G., et al. 2017, Mass Transfer and Disc Formation in AGB Binary Systems, MNRAS, 468, 4465 https://doi.org/10.1093/mnras/stx680
  13. Choi, B.-E., Chang, S.-J., Lee, H.-G., & Lee, H.-W. 2020, Line Formation of Raman-scattered He ii λ4851 in an Expanding Spherical H i Shell in Young Planetary Nebulae, ApJ, 889, 2 https://doi.org/10.3847/1538-4357/ab61f9
  14. Choi, B.-E., & Lee, H.-W. 2020, Discovery of Raman-scattered He ii λ6545 in the Planetary Nebulae NGC 6886 and NGC 6881, ApJL, 903, 39 https://doi.org/10.3847/1538-4357/abb6fd
  15. de Val-Borro, M., Karovska, M., Sasselov, D. D., & Stone, J. M. 2017, Three-dimensional Hydrodynamical Models of Wind and Outburst-related accretion in Symbiotic Systems, MNRAS, 468, 3408 https://doi.org/10.1093/mnras/stx684
  16. Dopita, M. A., Nicholls, D. C., Sutherland, R. S., et al. 2016, The Discovery of Raman Scattering in H II regions, ApJL, 824, L13 https://doi.org/10.3847/2041-8205/824/1/L13
  17. Eide, M. B., Gronke, M., Dijkstra, M., & Hayes, M., 2018 ApJ, Unlocking the Full Potential of Extragalactic Lyα through Its Polarization Properties, 856, 156 https://doi.org/10.3847/1538-4357/aab5b7
  18. Groves, B., Dopita, M. A., Williams, R. E., & Hua, C.-T. 2002, The Internal Extinction Curve of NGC 6302 and Its Extraordinary Spectrum, PASA, 19, 425 https://doi.org/10.1071/AS02010
  19. Harries, T. J., & Howarth, I. D. 1996, Raman Scattering in Symbiotic Stars. I. Spectropolarimetric Observations, A&AS, 119, 61 https://doi.org/10.1051/aas:1996228
  20. Heo, J.-E., & Lee, H.-W. 2015, Accretion Flow and Disparate Profiles of Raman Scattered O vi λλ1032, 1038 in the Symbiotic Star V1016 Cygni, JKAS, 48, 105
  21. Heo, J.-E., Angeloni, R., Di Mille, F., et al. 2016, A Profile Analysis of Raman-scattered O vi Bands at 6825 Å and 7082 Å in Sanduleak's Star, ApJ, 833, 286 https://doi.org/10.3847/1538-4357/833/2/286
  22. Jung, Y.-C., & Lee, H.-W. 2004, Centre Shift of the Raman Scattered He ii λ4850 in the Symbiotic Star V1016 Cygni, MNRAS, 355, 221 https://doi.org/10.1111/j.1365-2966.2004.08311.x
  23. Kang, E.-H., Lee, B.-C., & Lee, H.-W. 2009, Raman-Scattered He ii λ6545 in the Young and Compact Planetary Nebula NGC 6790, ApJ, 695, 542 https://doi.org/10.1088/0004-637X/695/1/542
  24. Lee, H.-W., & Park, M.-G. 1999, Toward the Evidence of the Accretion Disk Emission in the Symbiotic Star RR Telescopii, ApJL, 515, L89 https://doi.org/10.1086/311977
  25. Lee, H.-W. 2000, Raman-Scattering Wings of Hα in Symbiotic Stars, ApJ, 541, 25 https://doi.org/10.1086/309391
  26. Lee, H.-W., Kang, Y.-W., & Byun, Y.-I. 2001, Raman-scattered He ii Line in the Planetary Nebula M2-9 and in the Symbiotic Stars RR Telescopii and He 2-106, ApJ, 551, 121
  27. Lee, H.-W., Jung, Y.-C., Song, I.-O., & Ahn, S.-H. 2006, Raman-scattered He ii λλ4850, 6545 in the Young and Compact Planetary Nebula IC 5117, ApJ, 636, 1045 https://doi.org/10.1086/498143
  28. Lee, K.-W., & Lee, H.-W. 1997, On the Profiles and the Polarization of Raman-scattered Emission Lines in Symbiotic Stars - II. Numerical Simulations, MNRAS, 292, 573 https://doi.org/10.1093/mnras/292.3.573
  29. Lee, Y.-M., Lee, H.-W., Lee, H.-G., & Angeloni, R. 2019, Stellar-wind Accretion and Raman-scattered O vi Features in the Symbiotic Star AG Draconis, MNRAS, 487, 2166 https://doi.org/10.1093/mnras/stz1374
  30. Miller, J. S., & Goodrich, R. W. 1990, Spectropolarimetry of High-polarization Seyfert 2 Galaxies and Unified Seyfert Theories, ApJ, 355, 456 https://doi.org/10.1086/168780
  31. Nussbaumer, H., Schmid, H. M., & Vegel, M. 1989, Raman Scattering as a Diagnostic Possibility in Astrophysics, A&A, 211, 27
  32. Pequignot, D., Baluteau, J.-P., Morisset, C., & Boisson, C. 1997, NGC7027: Discovery of a Raman Line in a Planetary Nebula, A&A, 323, 217
  33. Saladino, M. I., Pols, O. R., van der Helm, E., et al. 2018, Gone with the Wind: The Impact of Wind Mass Transfer on the Orbital Evolution of AGB Binary Systems, A&A, 618, A50 https://doi.org/10.1051/0004-6361/201832967
  34. Saslow, W. M., & Mills, D. L. 1969, Raman Scattering by Hydrogenic Systems, Phys. Rev., 187, 1025 https://doi.org/10.1103/PhysRev.187.1025
  35. Sakurai, J. J. 1967, Advanced Quantum Mechanics (Reading, MA: Addison-Wesley)
  36. Schild, H., & Schmid, H. M. 1996, Spectropolarimetry of Symbiotic Stars. On the Binary Orbit and the Geometric Structure of V1016 Cygni, A&A, 310, 211
  37. Schmid, H. M. 1989, Identification of the Emission Bands at 6830, 7088 Å, A&A, 211, 31
  38. Schmid, H. M. 1992, Monte-Carlo Simulations of Raman Scattered O vi Emission Lines in Symbiotic Stars, A&A, 254, 224
  39. Schmid, H. M. 1995, Monte Carlo Simulations of the Rayleigh Scattering Effects in Symbiotic Stars, MNRAS, 275, 227 https://doi.org/10.1093/mnras/275.2.227
  40. Seon, K.-I., Min, K. W., Choi, C. S., & Nam, U. W. 1994, Monte Carlo Simulation of Comptonization in a Spherical Shell Geometry, JKAS, 27, 45
  41. Seon, K.-I. 2009, Monte-Carlo Simulation of the Dust Scattering, PKAS, 24, 43
  42. Seon, K.-I. 2015, Monte-Carlo Radiative Transfer Model of the Diffuse Galactic Light, JKAS, 47, 57
  43. Seon, K.-I., & Kim, C.-G. 2020, Lyα Radiative Transfer: Monte-Carlo Simulation of the Wouthuysen-Field Effect, ApJS, 250, 9 https://doi.org/10.3847/1538-4365/aba2d6
  44. Sekeras, M., & Skopal, A., 2015, Mass-loss Rate by the Mira in the Symbiotic Binary V1016 Cygni from Raman Scattering, ApJ, 812, 162 https://doi.org/10.1088/0004-637X/812/2/162
  45. Shore, S. N., Wahlgren, G. M., Genovali1, K., et al. 2010, The Spectroscopic Evolution of the Symbiotic Star AG Draconis: I. The O vi Raman, Balmer, and Helium Emission Line Variations during the Outburst of 2006-2008, A&A, 510, A70 https://doi.org/10.1051/0004-6361/200913367
  46. Storey, P. J., & Hummer, D. G. 1995, Recombination Line Intensities for Hydrogenic Ions - IV. Total Recombination Coefficients and Machine-readable Tables for Z = 1 to 8, MNRAS, 272, 41 https://doi.org/10.1093/mnras/272.1.41
  47. Tran, H. D. 2010, Hidden Double-peaked Emitters in Seyfert 2 Galaxies, ApJ, 711, 1174 https://doi.org/10.1088/0004-637X/711/2/1174
  48. van Gronigen, E. 1993, Further Evidence for Raman Scattering in RR Tel, MNRAS, 264, 975 https://doi.org/10.1093/mnras/264.4.975
  49. Yoo, J. J., Bak, J.-Y., & Lee, H.-W., 2002, Polarization of the Broad Hα Wing in Symbiotic Stars, MNRAS, 336, 467 https://doi.org/10.1046/j.1365-8711.2002.05753.x