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Tzu-Ching Chang

Photo of Tzu-Ching Chang


4800 Oak Grove Drive
M/S 169-237

Pasadena, CA 91109

Curriculum Vitae:

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Member of:

Structure of the Universe


Tzu-Ching received her PhD in 2003 at Columbia University, where she used the FIRST Radio Survey to make and exploit cosmic shear measurements of large scale structure in the universe.  She has worked on theory and data analysis of 21cm Cosmology and Line Intensity Mapping, exploring probes of cosmic dawn and reionization at high redshift and large-scale structure at low redshift. She is the PI of GBT-HIM, a 800MHz focal-plane array for the Green Bank Telescope for a Baryon Acoustic Oscillation HI survey at z~1, and is involved in TIME, a [CII] intensity mapper tracing the reionization process at 6<z<9.


  • B.S., Physics, National Taiwan University (1997)
  • Ph.D., Astrophysics, Columbia University (2003)

Professional Experience

  • Jet Propulsion Laboratory, Research Scientist (2017-present)
  • Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Assistant Research Fellow (2010-2016)
  • CITA/ASIAA, Postdoctoral Fellow (2006-2010)
  • UC Berkeley, TAC Fellow (2003-2006)

Community Service

  • NASA ATP and NSF Panel reviewer
  • ALMA Review Panel Science Assessor;  MWA TAC member
  • SOC member of multiple conferences.

Research Interests

  • Hydrogen 21-cm Cosmology, global signal and fluctuations
  • Line intensity mapping
  • Physics and probes of the Cosmic Dawn and Epoch of Reionization
  • Formation, evolution and probes of cosmic structures
  • Weak Gravitational Lensing

Selected Awards

  • Elected TWAS Young Affiliate (2012-2016)

Selected Publications

  1. Ensemble Photometric Redshifts. N. Padmanabhan, M. White, T.-C. Chang, J. D. Cohn, O. Dor´e, G. Holder MNRAS, 2017, submitted.
  2. Spectral Lines De-confusion in an Intensity Mapping Survey Y.-T. Cheng, T.-C. Chang, J. J. Bock, C. M. Bradford, A. Cooray ApJ, 2016, 832, 165, arXiv:1604.07833
  3. A Practical Theorem on Using Interferometry to Measure the Global 21-cm Signal T. Venumadhav, T.-C. Chang, O. Dor´e, C. M. Hirata ApJ, 2016, 826, 116, arXiv:1512.05248
  4. Accurate Polarization  Calibration at  800 MHz with  the Green Bank Telescope Y.-W. Liao, T.-C. Chang, C.-Y. Kuo, K. Masui, N. Opperman, U.-L. Pen, J. B. Peterson ApJ, 2016, 833, 289, arXiv:1610.04365
  5. Combining Galaxy and 21cm Surveys D. Cohn, M. White, T.-C. Chang, G. Holder, N. Padmanabhan, O. Dor´e, MNRAS, 2016, 457, 2068, arXiv:1511.07377
  6. Dense Magnetized Plasma Associated with a Fast Radio Burst Masui, H.-H Lin, J. Sievers, C. J. Anderson, T.-C. Chang, X. Chen, A. Ganguly, M. Jarvis,  C.-Y. Kuo,  Y.-C. Li,  Y.-W. Liao,  M. McLaughlin,  U.-L. Pen,  J. B. Peterson, A. Roman, P. T. Timbie, T. Voytek, J. K. Yadav, Nature, 2015, 528, 523
  7. Interpreting the Unresolved Intensity of Cosmologically Redshifted Line Radiation E. R. Switzer, T.-C. Chang, K. W. Masui, U.-L. Pen, T. C. Voytek ApJ, 2015, 815, 51
  8. Erasing the Milky Way:  new cleaning technique for intensity mapping data L. Wolz, C. Blake, F. B. Abdalla, C.M. Anderson, T.-C. Chang, K.W. Masui, P. Timbie, U.-L. Pen, T.C. Voytek, J. Yadav MNRAS, 2017, 464, 4938, arXiv:1510.06432
  9. First Results From COPSS: The CO Power Spectrum Survey G. K. Keating, G. C. Bower, D. P. Marrone, D. R. DeBoer, C. Heiles, T.-C. Chang, J. E. Carlstrom, C. H. Greer, D. Hawkins, J. W. Lamb, E. Leitch, A. D. Miller, S. Muchovej, D. P. Woody ApJ, 2015, 814, 140
  10. Exploiting Cross Correlations and Joint Analyses J. Rhodes, S. Allen, B. A. Benson, T.-C. Chang, R. de Putter et al., Astropartical Physics, 2015, 63, 42
  11. Cosmological Spectral Deconvolution R. de Putter, G. P. Holder, T.-C. Chang, O. Dor´e submitted to MNRAS, 2014, arXiv:1403.3727
  12. Determination of z ∼ 0.8 Neutral Hydrogen Fluctuations using the 21 cm In- tensity Mapping Auto-correlation E.R. Switzer, K. W. Masui, K. Bandura, L.-M. Calin, T.-C. Chang, X. Chen, Y.-C. Li, Y-W. Liao, A. Natarajan, U.-L. Pen, J.B. Peterson, J.R. Shaw, T.C. Voytek, MNRAS Letters, 2013, 434, 46
  13. A Refined Foreground-corrected Limit on the HI Power Spectrum at z=8.6 from the GMRT Epoch of Reionization Experiment G. Paciga, J. Albert, K. Bandura, T.-C. Chang, Y. Gupta, C. Hirata, J. Odegova, U.-L. Pen, J.B. Peterson, J. Roy, MNRAS, 2013, 433, 639
  14. Cross-correlations as a Carbon Monoxide Detector A. Pullen, T.-C. Chang, O. Dor´e, A. Lidz ApJ, 2013, 768, 15
  15. The Weight of Emptiness: The Gravitational Lensing Signal of Stacked Voids E. Krause, T.-C. Chang, O. Dor´e, K. Umetsu, ApJL, 2013, 762, 20
  16. The Baryon Acoustic Oscillation Broadband and Broad-beam Array:  Design Overview and Sensitivity Forecasts, J. Pober, A. R. Parsons, D. R. DeBoer, P. McDonald, M. McQuinn, J. E. Aguirre, Z. Ali, R. F. Bradley, T.-C. Chang, M. F. Morales, AJ, 2013, 145, 65
  17. Measurement of 21 cm brightness fluctuations at z ∼ 0.8 in cross-correlation K. W. Masui, E.R. Switzer, N. Banavar, K. Bandura, C. Blake, L.-M. Calin, T.-C. Chang, X. Chen, Y.-C. Li, Y-W. Liao, A. Natarajan, U.-L. Pen, J.B. Peterson, J.R. Shaw, T.C. Voytek, ApJL, 2013, 763, 20
  18. Intensity Mapping with Carbon Monoxide Emission Lines and the Redshifted 21 cm Line, A. Lidz, S. Furlanetto, P. S. Oh, J. Aguirre, T.-C. Chang, O. Dor´e, J. R. Pritchard, ApJ, 2011, 741, 70
  19. The GMRT-EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z ∼ 8.6, G. Paciga, T.-C. Chang, Y. Gupta, R. Nityanada, J. Odegova, U.-L. Pen, J. Peterson, J. Roy, K. Sigurdson, MNRAS, 2011,413, 1174
  20. An intensity map of hydrogen 21-cm emission at redshift z ∼ 0.8, T.-C. Chang, U.-L. Pen, K. Bandura, J. B. Peterson, Nature, 2010, 466, 463
  21. Enhanced Detectability of Pre-reionization 21 cm Structure, M. Alvarez, U.-L. Pen, T.-C. Chang, ApJ Letters, 2010, 723, 17
  22. The GMRT EoR Experiment: Limits on Polarized Sky Brightness at 150 MHz, U.-L. Pen, T.-C. Chang, J. B. Peterson, J. Roy, Y. Gupta, C. Hirata, J. Odegova, K. Sigurdson, MNRAS, 2009, 399, 181
  23. First Detection of Cosmic Structure in the 21-cm Intensity Field, U.-L. Pen, L. Staveley-Smith, J. B. Peterson, T.-C. Chang, MNRAS Letters., 2009, 394, 6
  24. Baryon Acoustic Oscillation Intensity Mapping of Dark Energy, T.-C. Chang, U.-L. Pen, J. B. Peterson, P. McDonald, Phys. Rev. Lett., 2008, 100, 091303
  25. Mergers and Bubble Growth during Reionization, J. D. Cohn, T.-C. Chang, MNRAS, 2007, 374, 72
  26. Weak Lensing by Large-Scale Structure with the FIRST Radio Survey, T.-C. Chang, A. Refregier, & D. J. Helfand, ApJ, 2004, 617, 794
  27. Shape Reconstruction and Weak Lensing Measurement with Interferometers: A Shapelet Approach, T.-C. Chang, A. Refregier, ApJ, 2001, 570, 447
  28. A Search for H I in E+A Galaxies, T.-C. Chang, J. H. van Gorkom, A. I. Zabludoff, D. Zaritsky, J. C. Mihos, AJ, 2001, 121, 1965
  29. Modeling the Radio Background from the First Black Holes at Cosmic Dawn: Implications for the 21 cm Absorption Amplitude. A. Ewall-Wice, T.-C. Chang, J. Lazio, O. Dor ́e, M. Seiffert, R. A. Monsalve, 2018, submitted, arXiv:1803.01815
  30. A Foreground Removal Strategy for Future [CII] Intensity Mapping Experiments Using Galaxies Selected by Stellar Mass and Redshift. G. Sun, ..., T.-C. Chang, et al., 2018, to appear in ApJ, arXiv:1610.10095
  31. Search for CII Emission on Cosmological Scales at Redshift z ∼ 2.6. A. Pullen, P. Serra, T.-C. Chang, O. Dor ́e, S. Ho, 2017, submitted, arXiv:1707.06172
  32. Lack of small-scale clustering in 21-cm intensity maps crossed with 2dF galaxy densities at z ∼ 0.08. C. Anderson, ..., T.-C. Chang, et al., 2018, to appear in MNRAS, arXiv:1710.00424