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Constraining Reionization with Lyα Emitting Galaxies

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Book cover Understanding the Epoch of Cosmic Reionization

Part of the book series: Astrophysics and Space Science Library ((ASSL,volume 423))

Abstract

Neutral diffuse intergalactic gas that existed during the Epoch of Reionization (EoR) suppresses Lyα flux emitted by background galaxies. In this chapter I summarise the increasing observational support for the claim that Lyα photons emitted by galaxies at z > 6 are suppressed by intervening HI gas. I describe key physical processes that affect Lyα transfer during the EoR. I argue that in spite of the uncertainties associated with this complex multiscale problem, the data on Lyα emitting galaxies at \( z=0\!\!-\!\!6 \) strongly suggests that the observed reduction in Lyα flux from galaxies at z > 6 is due to additional intervening HI gas. The main question is what fraction of this additional HI gas is in the diffuse neutral IGM. I summarise how future surveys on existing and incoming instruments are expected to reduce existing observational uncertainties enormously. With these improved data we will likely be able to nail down reionization with Lyα emitting galaxies.

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Notes

  1. 1.

    The ‘effective’ optical depth in the Lyα forest exceeds unity, τ eff > 1 at \( z\stackrel{>}{\sim }4 \) (see e.g. Fig. 3 of [21]).

  2. 2.

    Photons that do scatter in the diffuse neutral IGM form so called ‘Loeb-Rybicki halos’ [46], which are several orders of magnitude fainter than the currently observed halos (see Fig. A1 of [15]).

  3. 3.

    This reduced sensitivity to CGM/IGM opacity is important as we expect its opacity to Lyα photons to increase with redshift, while observations indicate it is increasingly easy to detect Lyα flux from galaxies towards higher redshifts from z = 0 to z = 6.

  4. 4.

    The quantity x HI will refer to the volume averaged neutral fraction of hydrogen throughout this chapter.

  5. 5.

    During the final stages of preparation, a preprint by Choudhury et al. [10] appeared which constrained \( x_{\mathrm{HI}} \sim 0.3 \) at \( z \sim 7 \) for a model that is similar to that of Mesinger et al. [53]. Choudhury et al. [10] adopt a steeper EW-PDF P 6(EW), which makes all Lyα emitting galaxies fainter by a factor of \( \sim 0.8 \), and could explain their somewhat smaller required x HI. This further illustrates how current observational uncertainties on Lyα EW-PDFs at \( z \sim 6 \) and \( z \sim 7 \) limit our ability to constrain x HI.

  6. 6.

    http://www.eso.org/sci/facilities/develop/instruments/muse.html.

  7. 7.

    http://www.srl.caltech.edu/sal/keckcosmic-web-imager.html.

  8. 8.

    http://www.naoj.org/Projects/HSC/.

  9. 9.

    The CGM may be more opaque in overdense regions of the Universe, which may make it more difficult to see LAEs in overdense regions. Thus the opacity of the CGM could counteract galaxy bias. This effect has been studied in detail post-reionization by e.g [4, 81, 83].

  10. 10.

    Lidz et al. [45] note that LAE-21 cm cross-correlation is actually sensitive to the characteristic HII regions size around LAEs which are detectable, which especially during the early stages of reionization is larger than the true characteristic HII bubble size. While the LAE-21 cm cross-correlation is likely easier detect, it may be more difficult to infer characteristic HII bubble size from this correlation than from the galaxy-21 cm correlation.

  11. 11.

    http://www.mwatelescope.org/.

  12. 12.

    There exists significant variation in observed line profiles even at a fixed redshift and observed flux, and so we do not expect spectra of in individual galaxies to be able to distinguish between different mechanisms.

  13. 13.

    In the most extreme case in which outflows shift all photons significantly (i.e. \( \stackrel{>}{\sim }200 \) km s−1) to the red side of the systemic velocity of the galaxy, we would expect very little scattering in the CGM.

References

  1. Barkana, R. 2004, MNRAS, 347, 59

    Article  ADS  Google Scholar 

  2. Barnes, L. A., Garel, T., Kacprzak, G.G. 2014, PASP, 126, 9698

    Article  Google Scholar 

  3. Becker, G. D., & Bolton, J. S. 2013, MNRAS, 436, 1023

    Article  ADS  Google Scholar 

  4. Behrens, C., & Niemeyer, J. 2013, A&A, 556, A5

    Article  ADS  Google Scholar 

  5. Bolton, J. S., & Haehnelt, M. G. 2013, MNRAS, 429, 1695

    Article  ADS  Google Scholar 

  6. Bouwens, R. J., Illingworth, G. D., Oesch, P. A., et al. 2012, ApJ, 754, 83

    Article  ADS  Google Scholar 

  7. Caruana, J., Bunker, A. J., Wilkins, S. M., et al. 2012, MNRAS, 427, 3055

    Article  ADS  Google Scholar 

  8. Caruana, J., Bunker, A. J., Wilkins, S. M., et al. 2013, arXiv:1311.0057

    Google Scholar 

  9. Cassata, P., Tasca, L. A. M., Le Fevre, O., et al. 2014, arXiv:1403.3693

    Google Scholar 

  10. Choudhury, T. R., Puchwein, E., Haehnelt, M. G., & Bolton, J. S. 2014, arXiv:1412.4790

    Google Scholar 

  11. Clément, B., Cuby, J.-G., Courbin, F., et al. 2012, A&A, 538, A66

    Article  ADS  Google Scholar 

  12. Dayal, P., Maselli, A., & Ferrara, A. 2011, MNRAS, 410, 830

    Article  ADS  Google Scholar 

  13. Dijkstra, M., Lidz, A., & Wyithe, J. S. B. 2007a, MNRAS, 377, 1175

    Article  ADS  Google Scholar 

  14. Dijkstra, M., Wyithe, J. S. B., & Haiman, Z. 2007b, MNRAS, 379, 253

    Article  ADS  Google Scholar 

  15. Dijkstra, M., & Wyithe, J. S. B. 2010, MNRAS, 408, 352

    Article  ADS  Google Scholar 

  16. Dijkstra, M., Mesinger, A., & Wyithe, J. S. B. 2011, MNRAS, 414, 2139

    Article  ADS  Google Scholar 

  17. Dijkstra, M., & Wyithe, J. S. B. 2012, MNRAS, 419, 3181

    Article  ADS  Google Scholar 

  18. Dijkstra, M., Wyithe, S., Haiman, Z., Mesinger, A., & Pentericci, L. 2014, MNRAS, 440, 3309

    Article  ADS  Google Scholar 

  19. Dijkstra, M. 2014, PASA, 31, e040

    Article  ADS  Google Scholar 

  20. Faisst, A. L., Capak, P., Carollo, C. M., Scarlata, C., & Scoville, N. 2014, ApJ, 788, 87

    Article  ADS  Google Scholar 

  21. Faucher-Giguère, C.-A., Prochaska, J. X., Lidz, A., Hernquist, L., & Zaldarriaga, M. 2008, ApJ, 681, 831

    Article  ADS  Google Scholar 

  22. Finkelstein, S. L., Papovich, C., Salmon, B., et al. 2012, ApJ, 756, 164

    Article  ADS  Google Scholar 

  23. Fontana, A., Vanzella, E., Pentericci, L., et al. 2010, ApJ, 725, L205

    Article  ADS  Google Scholar 

  24. Furlanetto, S. R., Zaldarriaga, M., & Hernquist, L. 2004, ApJ, 613, 1

    Article  ADS  Google Scholar 

  25. Furlanetto, S. R., Zaldarriaga, M., & Hernquist, L. 2006a, MNRAS, 365, 1012

    Article  ADS  Google Scholar 

  26. Furlanetto, S. R., Oh, S. P., & Briggs, F. H. 2006b, Physics Reports, 433, 181

    Article  ADS  Google Scholar 

  27. Gnedin, N. Y., & Prada, F. 2004, ApJ, 608, L77

    Article  ADS  Google Scholar 

  28. Gronke, M., Dijkstra, M., Trenti, M., & Wyithe, S. 2015, MNRAS, 449, 1284

    Article  ADS  Google Scholar 

  29. Haiman, Z., & Spaans, M. 1999, ApJ, 518, 138

    Article  ADS  Google Scholar 

  30. Haiman, Z. 2002, ApJ, 576, L1

    Article  ADS  MathSciNet  Google Scholar 

  31. Hayes, M., Schaerer, D., Ostlin, G., et al. 2011, ApJ, 730, 8

    Article  ADS  Google Scholar 

  32. Hu, E. M., Cowie, L. L., & McMahon, R. G. 1998, ApJ, 502, L99

    Article  ADS  Google Scholar 

  33. Hutter, A., Dayal, P., Partl, A. M., Muller, V. 2014, MNRAS, 441, 2861

    Article  ADS  Google Scholar 

  34. Iliev, I. T., Shapiro, P. R., McDonald, P., Mellema, G., & Pen, U.-L. 2008, MNRAS, 391, 63

    Article  ADS  Google Scholar 

  35. Inoue, A. K., Iwata, I., & Deharveng, J.-M. 2006, MNRAS, 371, L1

    Article  ADS  Google Scholar 

  36. Jensen, H., Laursen, P., Mellema, G., et al. 2013, MNRAS, 428, 1366

    Article  ADS  Google Scholar 

  37. Jensen, H., Hayes, M., Iliev, I. T., et al. 2014, MNRAS, 444, 2114

    Article  ADS  Google Scholar 

  38. Jiang, L., Bian, F., Fan, X., et al. 2013, ApJ, 771, L6

    Article  ADS  Google Scholar 

  39. Jones, T. A., Ellis, R. S., Schenker, M. A., & Stark, D. P. 2013, ApJ, 779, 52

    Article  ADS  Google Scholar 

  40. Kashikawa, N., Shimasaku, K., Malkan, M. A., et al. 2006, ApJ, 648, 7

    Article  ADS  Google Scholar 

  41. Kashikawa, N., Shimasaku, K., Matsuda, Y., et al. 2011, ApJ, 734, 119

    Article  ADS  Google Scholar 

  42. Konno, A., Ouchi, M., Ono, Y., et al. 2014, arXiv:1404.6066

    Google Scholar 

  43. Kuhlen, M., & Faucher-Giguère, C.-A. 2012, MNRAS, 423, 862

    Article  ADS  Google Scholar 

  44. Laursen, P., Sommer-Larsen, J., & Razoumov, A. O. 2011, ApJ, 728, 52

    Article  ADS  Google Scholar 

  45. Lidz, A., Zahn, O., Furlanetto, S. R., et al. 2009, ApJ, 690, 252

    Article  ADS  Google Scholar 

  46. Loeb, A., & Rybicki, G. B. 1999, ApJ, 524, 527

    Article  ADS  Google Scholar 

  47. Madau, P., & Rees, M. J. 2000, ApJ, 542, L69

    Article  ADS  Google Scholar 

  48. Martin, C., Moore, A., Morrissey, P., et al. 2010, PROCSPIE, 7735

    Google Scholar 

  49. McGreer, I. D., Mesinger, A., & D’Odorico, V. 2015, MNRAS, 447, 499

    Article  ADS  Google Scholar 

  50. McQuinn, M., Hernquist, L., Zaldarriaga, M., & Dutta, S. 2007, MNRAS, 381, 75

    Article  ADS  Google Scholar 

  51. Mesinger, A., & Furlanetto, S. R. 2008a, MNRAS, 385, 1348

    Article  ADS  Google Scholar 

  52. Mesinger, A., & Furlanetto, S. R. 2008b, MNRAS, 386, 1990

    Article  ADS  Google Scholar 

  53. Mesinger, A., Aykutalp, A., Vanzella, E., et al. 2015, MNRAS, 446, 566

    Article  ADS  Google Scholar 

  54. Momose, R., Ouchi, M., Nakajima, K., et al. 2014, MNRAS, 442, 110

    Article  ADS  Google Scholar 

  55. Morales, M. F., & Wyithe, J. S. B. 2010, ARAA, 48, 127

    Article  ADS  Google Scholar 

  56. Ono, Y., Ouchi, M., Mobasher, B., et al. 2012, ApJ, 744, 83

    Article  ADS  Google Scholar 

  57. Ota, K., Iye, M., Kashikawa, N., et al. 2010, ApJ, 722, 803

    Article  ADS  Google Scholar 

  58. Ota, K., Richard, J., Iye, M., et al. 2012, MNRAS, 423, 2829

    Article  ADS  Google Scholar 

  59. Ouchi, M., Shimasaku, K., Akiyama, M., et al. 2008, ApJS, 176, 301

    Article  ADS  Google Scholar 

  60. Ouchi, M., Shimasaku, K., Furusawa, H., et al. 2010, ApJ, 723, 869

    Article  ADS  Google Scholar 

  61. Papovich, C., Finkelstein, S. L., Ferguson, H. C., Lotz, J. M., & Giavalisco, M. 2011, MNRAS, 412, 1123

    ADS  Google Scholar 

  62. Pentericci, L., Fontana, A., Vanzella, E., et al. 2011, ApJ, 743, 132

    Article  ADS  Google Scholar 

  63. Pentericci, L., Vanzella, E., Fontana, A., et al. 2014, arXiv:1403.5466

    Google Scholar 

  64. Pritchard, J. R., & Loeb, A. 2012, Reports on Progress in Physics, 75, 086901

    Article  ADS  Google Scholar 

  65. Santos, M. R. 2004, MNRAS, 349, 1137

    Article  ADS  Google Scholar 

  66. Schenker, M. A., Stark, D. P., Ellis, R. S., et al. 2012, ApJ, 744, 179S

    Article  ADS  Google Scholar 

  67. Schenker, M. A., Ellis, R. S., Konidaris, N. P., & Stark, D. P. 2014, arXiv:1404.4632

    Google Scholar 

  68. Schmidt, K. B., Treu, T., Brammer, G. B., et al. 2014, ApJ, 782, L36

    Article  ADS  Google Scholar 

  69. Shibuya, T., Ouchi, M., Nakajima, K., et al. 2014, ApJ, 788, 74

    Article  ADS  Google Scholar 

  70. Sobacchi, E., & Mesinger, A. 2015, arXiv:1505.02787

    Google Scholar 

  71. Stark, D. P., Ellis, R. S., Richard, J., et al. 2007, ApJ, 663, 10

    Article  ADS  Google Scholar 

  72. Stark, D. P., Ellis, R. S., Chiu, K., Ouchi, M., & Bunker, A. 2010, MNRAS, 408, 1628

    Article  ADS  Google Scholar 

  73. Stark, D. P., Ellis, R. S., & Ouchi, M. 2011, ApJ, 728, L2-L7

    Article  ADS  Google Scholar 

  74. Taylor, J., & Lidz, A. 2013, MNRAS, 2740

    Google Scholar 

  75. Trac, H. Y., & Gnedin, N. Y. 2011, Advanced Science Letters, 4, 228

    Article  ADS  Google Scholar 

  76. Treu, T., Trenti, M., Stiavelli, M., Auger, M. W., & Bradley, L. D. 2012, ApJ, 747, 27

    Article  ADS  Google Scholar 

  77. Treu, T., Schmidt, K. B., Trenti, M., Bradley, L. D., & Stiavelli, M. 2013, ApJ, 775, L29

    Article  ADS  Google Scholar 

  78. van Haarlem, M. P., Wise, M. W., Gunst, A. W., et al. 2013, A&A, 556, A2

    Article  ADS  Google Scholar 

  79. Verhamme, A., Schaerer, D., Atek, H., & Tapken, C. 2008, A&A, 491, 89

    Article  ADS  Google Scholar 

  80. Wiersma, R. P. C., Ciardi, B., Thomas, R. M., et al. 2013, MNRAS, 432, 2615

    Article  ADS  Google Scholar 

  81. Wyithe, J. S. B., & Dijkstra, M. 2011, MNRAS, 415, 3929

    Article  ADS  Google Scholar 

  82. Zheng, Z., Cen, R., Trac, H., & Miralda-Escudé, J. 2010, ApJ, 716, 574

    Article  ADS  Google Scholar 

  83. Zheng, Z., Cen, R., Trac, H., & Miralda-Escudé, J. 2011, ApJ, 726, 38

    Article  ADS  Google Scholar 

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Acknowledgements

I would like to thank Andrei Mesinger for permission to reproduce figures from his work.

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  1. Institute for Theoretical Astrophysics, University of Oslo, 1029, 0315, Oslo, Norway

    Mark Dijkstra

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  1. Astronomy, Scuola Normale Superiore Astronomy, Pisa, Italy

    Andrei Mesinger

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Dijkstra, M. (2016). Constraining Reionization with Lyα Emitting Galaxies. In: Mesinger, A. (eds) Understanding the Epoch of Cosmic Reionization. Astrophysics and Space Science Library, vol 423. Springer, Cham. https://doi.org/10.1007/978-3-319-21957-8_5

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