Dr. Nithyanandan Thyagarajan

Address National Radio Astronomy Observatory Webpage https://tnithyanandan.wordpress.com/ 1003 Lopezville Rd E-mail [email protected] Socorro, NM 87801, USA Phone +1 (575) 835-7095

Education

2004-2011 PhD in Astronomy, Columbia University, New York, NY, USA. Thesis Advisor: Prof. David J. Helfand Ph.D. dissertation available for download at https://tnithyanandan.wordpress.com/

2006-2007 M.Phil. in Astronomy, Columbia University, New York, NY, USA

2004-2006 M.A. in Astronomy, Columbia University, New York, NY, USA

2000-2004 Bachelor of Technology in Electrical Engineering, IIT Madras, India. Thesis Advisor: Prof. Harishankar Ramachandran

Professional Experience

Sep 2017 - National Radio Astronomy Observatory, Socorro, NM, USA Present Jansky Postdoctoral Fellow Collaborations: Hydrogen Epoch of Reionization (HERA), Square Kilometre Array (SKA), Murchison Wideﬁeld Array (MWA)

Oct 2016 - Arizona State University, School of Earth and Space Exploration, Tempe, AZ, USA Aug 2017 Assistant Research Scientist Collaborations: Hydrogen Epoch of Reionization (HERA), Square Kilometre Array (SKA), Murchison Wideﬁeld Array (MWA)

Sep 2013 - Arizona State University, School of Earth and Space Exploration, Tempe, AZ, USA Sep 2016 Post-doctoral Research Associate Collaborations: Hydrogen Epoch of Reionization (HERA), Square Kilometre Array (SKA), Murchison Wideﬁeld Array (MWA)

May 2011 - Raman Research Institute, Bangalore, India Jul 2013 Pancharatnam Post-doctoral Fellow Collaborations: Murchison Wideﬁeld Array (MWA)

1 of 14 Research Grants

• Principal investigator of a $600,000 grant proposal funded by the National Science Foundation (NSF) Advanced Technologies and Instrumentation (ATI) division for “First Deployment of an E-Field Parallel Imaging Correlator with the LWA” at Sevilleta LWA station in collaboration with Prof. Greg Taylor (UNM), Prof. Gregg Hallinan (Caltech), Prof. Aaron Parsons (Berkeley), Prof. Judd Bowman (ASU), Prof. Miguel Morales (UW), Prof. Ralph Wijers (U. Amsterdam, AARTFAAC-LOFAR) and Prof. Dan Werthimer (Berkeley).

Peer-reviewed Publications

1. Thyagarajan, N., Beardsley, A. P., Bowman, J. D., & Morales, M. F., Monthly Notices of the Royal Astronomical Society, 467, 715 (2017), “A Generic and Efficient E-field Parallel Imag- ing Correlator for Next-Generation Radio Telescopes” 2. Thyagarajan, N., Parsons, A. R., DeBoer, D. R., Bowman, J. D., et al., The Astrophysical Journal, 825, 9 (2016), “Effects of Antenna Beam Chromaticity on Redshifted 21 cm Power Spec- trum and Implications for Hydrogen Epoch of Reionization Array” 3. Beardsley, A. P., Thyagarajan, N., Morales, M. F., & Bowman, J. D., Monthly Notices of the Royal Astronomical Society (2017), “An Efficient Feedback Calibration Algorithm for Di- rect Imaging Radio Telescopes” 4. Thyagarajan, N., Jacobs, D. C., Bowman, J. D., et al., The Astrophysical Journal Letters, 807, 28 (2015), “Confirmation of Wide-field Signatures in Redshifted 21 cm Power Spectra” 5. Thyagarajan, N., Jacobs, D. C., Bowman, J. D., et al., The Astrophysical Journal, 804, 14 (2015), “Foregrounds in Wide-Field Redshifted 21 cm Power Spectra” 6. Thyagarajan, N., Udaya Shankar, N., Subrahmanyan, R., et al., The Astrophysical Journal, 776, 6 (2013), “A Study of Fundamental Limitations to Statistical Detection of Redshifted HI from the Epoch of Reionization” 7. Thyagarajan, N., Helfand, D. J., White, R. L., & Becker, R. H., The Astrophysical Journal, 742, 49 (2011), “Variable and Transient Radio Sources in the FIRST Survey” 8. DeBoer, D. R., Parsons, A. R., …Thyagarajan, N., et al. [54 authors], Publications of the As- tronomical Society of Pacific, 129, 045001 (2017), “Hydrogen Epoch of Reionization Array (HERA)” 9. Kapinska, A. D., Staveley-Smith, L., Crocker, R., …Thyagarajan, N., et al. [70 authors], The Astrophysical Journal, 838, 68 (2017), “Spectral Energy Distribution and Radio Halo of NGC 253 at Low Radio Frequencies” 10. Patra, N., Parsons, A. R., DeBoer, D. R., Thyagarajan, N., et al., arXiv:1701.03209 (2017), Exper- imental Astronomy (in press), “The Hydrogen Epoch of Reionization Array Dish III : Mea- suring Chromaticity of Prototype Element with Reflectometry” 11. Nunhokee, C. D., Bernardi, G., Kohn, S. A., Aguirre, J. E., Thyagarajan, N., et al., The Astrophys- ical Journal (2017), “Constraining polarized foregrounds for eor experiments II: Simula- tions of polarization leakage in the avoidance scheme” 12. Kittiwisit, P.,Bowman, J. D., Jacobs, D. C., Thyagarajan, N. & Beardsley, A. P., arXiv:1708.00036 (2017), Monthly Notices of the Royal Astronomical Society (Accepted, in press), “Sensitivity of the Hydrogen Epoch of Reionization Array and its Build-out Stages to One-point Statistics from Redshifted 21 cm Observations”

2 of 14 13. Paul, S., Sethi, S. K., …Thyagarajan, N., et al. [54 authors], The Astrophysical Journal, 833, 213 (2016), “Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization” 14. Beardsley, A. P.,Hazelton, B. J., …Thyagarajan, N., et al. [66 authors], The Astrophysical Jour- nal, 833, 102 (2016), “First Season MWA EoR Power Spectrum Results at Redshift 7” 15. Neben, A., Bradley, R. F., …Thyagarajan, N., et al. [29 authors], The Astrophysical Journal, 826, 199 (2016), “The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Mea- surements and Science Implications” 16. Ewall-Wice, A., Bradley, R. F., …Thyagarajan, N., et al. [27 authors], The Astrophysical Jour- nal, 831, 196 (2016), “The HERA Dish II: Electromagnetic Simulations and Science Impli- cations” 17. Ewall-Wice, A., Dillon, J. S., …Thyagarajan, N., et al. [65 authors], Monthly Notices of the Royal Astronomical Society, 460, 4320 (2016), “First limits on the 21 cm power spectrum during the epoch of X-ray heating” 18. Lenc, E., Gaensler, B. M., …Thyagarajan, N., et al. [79 authors], The Astrophysical Journal, 830, 38 (2016), “Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole” 19. Carroll, P.,Line, J., …Thyagarajan, N., et al. [64 authors], The Monthly Notices of the Royal As- tronomical Society, 461, 4151 (2016), “A high reliability survey of discrete Epoch of Reion- ization foreground sources in the MWA EoR0 field” 20. Jacobs, D. C., Hazelton, B. J., …Thyagarajan, N., et al. [64 authors], The Astrophysical Journal, 825, 114 (2016), “The Murchison Widefield Array 21 cm Power Spectrum Analysis Method- ology” 21. Pober, J. C., Hazelton, B. J., …Thyagarajan, N., et al. [68 authors], The Astrophysical Journal, 819, 8 (2016), “The Importance of Widefield Foreground Removal for 21 cm Cosmology: A Demonstration with Early MWA Epoch of Reionization Observations” 22. Offringa, A. R., Trott, C. M., …Thyagarajan, N., et al. [41 authors], The Monthly Notices of the Royal Astronomical Society, 458, 1057 (2016), “Parametrising Epoch of Reionization foregrounds: A deep survey of low-frequency point-source spectra with the MWA” 23. Trott, C. M., Pindor, B., …Thyagarajan, N., et al. [52 authors], The Astrophysical Journal, 818, 139 (2016), “CHIPS: The Cosmological HI Power Spectrum Estimator” 24. Dillon, J. S., Neben, A. R., …Thyagarajan, N., et al. [55 authors], Physical Review D, 91, 123011 (2015), “Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data” 25. Offringa, A. R., Wayth, R. B., …Thyagarajan, N., et al. [65 authors], Publications of the Astro- nomical Society of Australia, 32, 8 (2015), “The Low-Frequency Environment of the Murchi- son Widefield Array: Radio-Frequency Interference Analysis and Mitigation”

Ph.D. Dissertation (2011): “Investigations in Time and of Space Using the FIRST Survey: Ra- dio Source Variability and the Evolution of FR II Quasars”, ProQuest Dissertations and Theses, Publication Number: AAT 3443779

Research Experience

3 of 14 2017 - Investigation of Novel and Alternate Approaches to Redshifted 21 cm Cosmology Present Collaborators: Prof. Chris L. Carilli (NRAO), Prof. Judd Bowman (ASU), Prof. Aaron Parsons (UC Berkeley), & HERA Collaboration Despite having theoretical sensitivity to make a high significance EoR detection, current EoR experiments using redshifted 21 cm observations at low frequencies such as MWA, PAPER, and LOFAR are severely limited by spectral systematics arising out of leakage from bright foregrounds, wide-field effects, reflections, non-redundancies and heterogeneous behavior among antennas, calibration errors, etc. I am investigating closure phase quan- tity as an alternate method to study spectral separability of the EoR signal and some of these systematics. Since closure quantities are independent of antenna-based calibration and calibration errors, they are immune to many of the aforementioned limitations.

2016 - Array Layout Specifications for HERA and SKA Present Collaborators: Prof. Judd Bowman (ASU), Prof. David DeBoer (UC Berkeley), Prof. Aaron Parsons (UC Berkeley), HERA & SKA Collaborations. Radio instruments have a lot of potential in this era of precision cosmology. Examples in- clude the Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometre Array (SKA). Construction of these arrays have already begun or will commence shortly. In- accuracies in layout will lead to loss of any assumed redundancy, baseline-dependent chromaticity, and significant mis-estimates and mis-subtraction of foreground contamination. Using Precision Radio Interferometry Simulator (PRISim), I am developing performance specifications on the accuracy of the layouts. These specifications will charac- terize the effect of HERA and SKA layout inaccuracies on their ability to calibrate (based on phase closure), loss of redundancy, and signal contamination due to foreground mis- estimation.

System Design Specifications for HERA and SKA Collaborators: Prof. Aaron Parsons (UC Berkeley), Prof. David DeBoer (UC Berkeley), Prof. Judd Bowman (ASU), HERA & SKA Collaborations. Despite a decade of observations with advanced experiments such as the Murchison Widefield Array (MWA), Low Frequency Array (LOFAR), Precision Array for Probing Epoch of Reionization (PAPER), detection of HI signal from the Epoch of Reionization (EoR) has remained elusive. This is primarily due to systematic limitations caused by bright foregrounds and instrumental effects. With comprehensive and high-precision simulations, I simulate an end-to-end system to understand these effects and devise techniques to mit- igate these effects by providing critical inputs to HERA and SKA system designs. My work provided a generic framework to set design constraints on the level of reflections in the system while current focus is on setting limits on calibration requirements due to devia- tions from redundancy in measurements.

2015 - Generic and Eﬃcient E-ﬁeld Parallel Imaging Correlator (EPIC) Present Collaborators: Prof. Judd Bowman (ASU), Prof. Miguel F.Morales (UW) & Adam Beardsley (ASU).

4 of 14 A software tool that implements a generic direct imaging algorithm, namely Modular Op- timal Fast Fourier (MOFF) imaging, which is a generic and eﬃcient alternative to conven- tional correlator (FX/XF) and imaging techniques currently in use in radio interferometry. Data processing including calibration and imaging use antenna-based electric ﬁelds without the need for cross-correlating antenna pairs to produce visibilities. It also relaxes the constraints that antennas have to be placed on a uniform grid for direct imaging and that the antennas must be identical. EPIC has a promising future for next-generation radio telescopes that have a dense, large-N antenna array layout such as HERA, LWA and SKA. An immediate-term science driver is the real-time search for radio transients. Work is un- derway to realize a GPU-based implementation of EPIC for LWA station in Sevilleta (New Mexico).

Beam characterization, Forecast of EoR HI signal and foregrounds for HERA and SKA Collaborators: Prof. Judd Bowman (ASU), HERA & SKA Collaborations. Using high precision simulations, characterizing chromaticity of the antenna beam and its performance, forecasting detection sensitivity and best windows in observing parameters for EoR HI observations using HERA, a top ranked project in the Astro2010 Decadal survey as well as the SKA. Parameters such as foreground mitigation through instrument design aspects such as spectral characteristics of antenna aperture and data analysis aspects such as baseline-based ﬂagging methods and direction-dependent foreground removal strategies will be considered in identifying the best observing strategy for these experiments.

2013 - Confirming predicted wide-field foreground signatures in EoR observations 2015 Collaborators: Prof. Judd Bowman (ASU), Daniel Jacobs (ASU) & MWA Collaboration. First and high-significance confirmation (using MWA data) of the pitchfork signature characteristic of foregrounds in EoR observations with wide-field instruments predicted earlier thus emphasizing the need for clever aperture designs with desirable antenna power patterns that suppress instrument sensitivity near the horizon for future instruments such as HERA and SKA.

Prediction of characteristic EoR foreground signatures observed by radio interferom- eters Collaborators: Prof. Judd Bowman (ASU), Daniel Jacobs (ASU) & MWA Collaboration. First detailed simulations of EoR signal and foregrounds as observed through radio interferometer arrays helped discover that wide-field instruments imprint a characteristic pitchfork signature in the power spectrum “wedge” – a signature which critically affects EoR signal sensitivity in important k-modes. Contamination from the pitchfork feature can be controlled by careful design of antenna apertures that suppress power pattern near the horizon and by using a sky model and baseline-based flagging technique. Simulations are publicly available for the radio astronomy community.

2011 - Statistical Foreground Modeling and EoR Sensitivity for the MWA 2013 Collaborators: Prof. Ravi Subrahmanyan (RRI), Prof. Udayashankar (RRI) & MWA Collaboration. Understanding fundamental limitations to EoR detection in HI power spectrum – classical source confusion, sidelobe confusion, and thermal noise – thereby estimating sensitivity of radio instruments such as MWA in EoR experiments with implications for observing strategies.

GMRT and PTF follow-up of VLA FIRST transients

5 of 14 Collaborators: Prof. K. S. Dwarakanath (RRI) & Prof. Shri Kulkarni (Caltech) Follow-up of ≳ 1600 variables and transients from the FIRST survey with the Palomar Transient Factory in the optical bands and 20 carefully chosen bright transients at low radio frequencies with the GMRT thereby characterizing the dynamic radio sky.

2007 - Radio variables & transients from the VLA FIRST survey 2011 Collaborators: Prof. David J. Helfand (Columbia University), Prof. Richard L. White (STScI) & Prof. Robert H. Becker (UC Davis) One of the biggest searches for radio variables and transients at mJy levels using the FIRST survey, constructing statistics of the variable/transient radio sky and probing unexplored regions of parameter-space in discovering new types of variable and transient objects. Using the FIRST survey, I estimated the VLA dish power pattern at 1.4 GHz to a very high accuracy than available with standard models in AIPS.

2005 - Angular size-redshift analysis from VLA FIRST data using FR-II sources 2007 Advisor: Prof. David J. Helfand, Columbia University. Veriﬁed that FR-II quasars behave as standard rods without intrinsic redshift evolution by assuming the currently accepted cosmological parameters and by using a combination of FIRST images and SDSS spectroscopic and photometric redshifts thereby creating the largest and homogeneous database of radio selected FR-II quasars.

Angular correlation of radio sources in the FIRST survey Advisor: Prof. David J. Helfand, Columbia University. Studied the angular correlation of radio sources down to mJy levels and using higher order statistics to study the radio clustering properties of the universe with optical magnitudes available from SDSS.

2004 - HI in the Perseus cluster using WSRT 2005 Advisor: Prof. Jacqueline van Gorkom, Columbia University. Investigated HI in selected galaxies sampling the inner and outer regions of the Perseus cluster using the data with the new WSRT back-end and also studying the two HI absorp- tions at the center of the cluster which are not very well understood.

2003 Understanding the performance of NNLS algorithm in synthesis imaging Advisors: Prof. Rajaram Nityananda, NCRA, Pune, India & Prof. Harishankar Ramachan- dran, IIT Madras, India. Experimented with the Non-Negative Least Squares algorithm assessing its performance and eﬃciency and compared to the CLEAN algorithm.

2002 Gravitational Waves in the linearized theory of gravity Advisor: Prof. Bala R. Iyer, RRI, Bangalore, India. Performed simulations of test particles under the inﬂuence of gravitational waves in the linearized theory of gravity.

Peer-reviewed Publications

1. Thyagarajan, N., Beardsley, A. P., Bowman, J. D., & Morales, M. F., Monthly Notices of the Royal Astronomical Society, 467, 715 (2017), “A Generic and Eﬃcient E-ﬁeld Parallel Imag-

6 of 14 ing Correlator for Next-Generation Radio Telescopes” 2. Thyagarajan, N., Parsons, A. R., DeBoer, D. R., Bowman, J. D., et al., The Astrophysical Journal, 825, 9 (2016), “Effects of Antenna Beam Chromaticity on Redshifted 21 cm Power Spec- trum and Implications for Hydrogen Epoch of Reionization Array” 3. Beardsley, A. P., Thyagarajan, N., Morales, M. F., & Bowman, J. D., [arXiv:1603.02126] (2015), will be accepted in the Monthly Notices of the Royal Astronomical Society pending few revi- sions, “AnEfficient Feedback Calibration Algorithm for Direct Imaging Radio Telescopes” 4. Thyagarajan, N., Jacobs, D. C., Bowman, J. D., et al., The Astrophysical Journal Letters, 807, 28 (2015), “Confirmation of Wide-field Signatures in Redshifted 21 cm Power Spectra” 5. Thyagarajan, N., Jacobs, D. C., Bowman, J. D., et al., The Astrophysical Journal, 804, 14 (2015), “Foregrounds in Wide-Field Redshifted 21 cm Power Spectra” 6. Thyagarajan, N., Udaya Shankar, N., Subrahmanyan, R., et al., The Astrophysical Journal, 776, 6 (2013), “A Study of Fundamental Limitations to Statistical Detection of Redshifted HI from the Epoch of Reionization” 7. Thyagarajan, N., Helfand, D. J., White, R. L., & Becker, R. H., The Astrophysical Journal, 742, 49 (2011), “Variable and Transient Radio Sources in the FIRST Survey” 8. Patra, N., Parsons, A. R., DeBoer, D. R., Thyagarajan, N., et al., arXiv:1701.03209 (2017), Sub- mitted to The Astrophysical Journal, “The Hydrogen Epoch of Reionization Array Dish III: Measuring Chromaticity of Prototype Element with Reflectometry” 9. Nunhokee, C. D., Bernardi, G., Kohn, S. A., Aguirre, J. E., Thyagarajan, N., et al. (2017), Sub- mitted to The Astrophysical Journal (manuscript draft available upon request), “Constraining polarized foregrounds for EoR experiments II: Simulations of polarization leakage in the avoidance scheme” 10. Kittiwisit, P.,Bowman, J. D., Jacobs, D. C., Thyagarajan, N. & Beardsley, A. P., arXiv:1610.06100 (2016), Submitted to The Astrophysical Journal, “Impact of Instrument Responses on the Detectability of One-point Statistics from Redshifted 21 cm Observations” 11. DeBoer, D. R., Parsons, A. R., …Thyagarajan, N., et al. [54 authors], Publications of the Astro- nomical Society of the Pacific, 129, 045001 (2016), “Hydrogen Epoch of Reionization Array (HERA)” 12. Kapinska, A. D., Staveley-Smith, L., …Thyagarajan, N., et al. [70 authors], [arXiv:1702.02434] (2017), Accepted in The Astrophysical Journal, “Spectral energy distribution and radio halo of NGC 253 at low radio frequencies” 13. Paul, S., Sethi, S. K., …Thyagarajan, N., et al. [54 authors], The Astrophysical Journal, 833, 213 (2016), “Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization” 14. Beardsley, A. P.,Hazelton, B. J., …Thyagarajan, N., et al. [66 authors], The Astrophysical Jour- nal, 833, 102 (2016), “First Season MWA EoR Power Spectrum Results at Redshift 7” 15. Neben, A., Bradley, R. F., …Thyagarajan, N., et al. [29 authors], The Astrophysical Journal, 826, 199 (2016), “The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Mea- surements and Science Implications” 16. Ewall-Wice, A., Bradley, R. F., …Thyagarajan, N., et al. [27 authors], The Astrophysical Jour- nal, 831, 196 (2016), “The HERA Dish II: Electromagnetic Simulations and Science Impli- cations”

7 of 14 17. Ewall-Wice, A., Dillon, J. S., …Thyagarajan, N., et al. [65 authors], Monthly Notices of the Royal Astronomical Society, 460, 4320 (2016), “First limits on the 21 cm power spectrum during the epoch of X-ray heating”

18. Lenc, E., Gaensler, B. M., …Thyagarajan, N., et al. [79 authors], The Astrophysical Journal, 830, 38 (2016), “Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole”

19. Carroll, P.,Line, J., …Thyagarajan, N., et al. [64 authors], The Monthly Notices of the Royal As- tronomical Society, 461, 4151 (2016), “A high reliability survey of discrete Epoch of Reion- ization foreground sources in the MWA EoR0 ﬁeld”

20. Jacobs, D. C., Hazelton, B. J., …Thyagarajan, N., et al. [64 authors], The Astrophysical Journal, 825, 114 (2016), “The Murchison Wideﬁeld Array 21 cm Power Spectrum Analysis Method- ology”

21. Pober, J. C., Hazelton, B. J., …Thyagarajan, N., et al. [68 authors], The Astrophysical Journal, 819, 8 (2016), “The Importance of Wideﬁeld Foreground Removal for 21 cm Cosmology: A Demonstration with Early MWA Epoch of Reionization Observations”

22. Oﬀringa, A. R., Trott, C. M., …Thyagarajan, N., et al. [41 authors], The Monthly Notices of the Royal Astronomical Society, 458, 1057 (2016), “Parametrising Epoch of Reionization foregrounds: A deep survey of low-frequency point-source spectra with the MWA”

23. Trott, C. M., Pindor, B., …Thyagarajan, N., et al. [52 authors], The Astrophysical Journal, 818, 139 (2016), “CHIPS: The Cosmological HI Power Spectrum Estimator”

24. Dillon, J. S., Neben, A. R., …Thyagarajan, N., et al. [55 authors], Physical Review D, 91, 123011 (2015), “Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Wideﬁeld Array 128-tile data”

25. Oﬀringa, A. R., Wayth, R. B., …Thyagarajan, N., et al. [65 authors], Publications of the Astro- nomical Society of Australia, 32, 8 (2015), “The Low-Frequency Environment of the Murchi- son Wideﬁeld Array: Radio-Frequency Interference Analysis and Mitigation”

8 of 14 Software Advancing Radio Interferometry

Precision Radio Interferometry Simulator (PRISim) I developed a generic and highly parallel radio interferometer array simulator for modern wide-field radio telescopes. This highly modular Python package utilizes Message Passing Interface (MPI) and can run in parallel across multiple nodes. Though developed for cosmology during the Epoch of Reionization, it can be be customized to applications across various radio instruments, a wide range of radio frequencies and observing parameters. It is publicly available at https://github.com/nithyanandan/PRISim. E-Field Parallel Imaging Correlator (EPIC) I developed an efficient, versatile, and highly parallel antenna electric field-based correlator-cum-imaging software demonstrator for next generation radio telescopes. It is highly modular and emulates real telescopes in software. It comes packed with the ultra-efficient MOFF architecture as well as traditional FX and XF architectures, besides imaging modules. It utilizes sparse matrix and parallelization routines for efficiency. It is aimed at particular applications to cosmology during the EoR and fast radio transients. It is available publicly at https://github.com/nithyanandan/EPIC. General Purpose Python Modules (AstroUtils) I developed general purpose modules that serve miscellaneous purposes such as signal and image processing, nearest neighbor and catalog matching, and function as dependencies for the aforementioned software packages. These modules can be found on https://github.com/nithyanandan/general.

Professional Talks, Conferences & Workshops

Feb. 2018 Cosmological Signals from Cosmic Dawn to the Present, Aspen, CO, USA New Approaches and Design Strategies to Detect Signals from the Cosmic Dawn

Jan. 2018 American Astronomical Society Meeting, Washington DC, USA Designing Successful Next-Generation Instruments to Detect the Epoch of Reion- ization Jan. 2018 National Radio Science Meeting (URSI), Boulder, CO, USA Deployment of a Novel Interferometer Architecture on the LWA-Sevilleta Station

Dec. 2017 Science at Low Frequencies IV, Sydney, Australia The efficient E-field Parallel Imaging Correlator (EPIC) and first deployment onLWA- Sevilleta station Nov. 2017 New Mexico Symposium, Socorro, NM, USA Searching for Neutral Hydrogen in the Early Universe and Progress with Low Frequency Radio Instruments Oct. 2017 International Astronomical Union Symposium 333, Dubrovnik, Croatia Status of Foreground and Instrument Challenges for 21cm EoR Experiments – Design and Analysis Strategies for SKA and HERA

May 2017 Invited seminar, National Radio Astronomy Observatory (NRAO), Socorro, NM, USA Expanding Science Frontiers at Low Frequencies

9 of 14 May 2017 American Astronomical Society Topical Conference Series, Palm Springs, CA, USA Enabling Future Large Searches for Exoplanet Auroral Emission with the EPIC Correlator Architecture Jan. 2017 Invited seminar, University of Colorado, Boulder, CO, USA Evolution of 21 cm EoR experiments: Present and Future

Jan. 2017 Invited talk (Video conference), AARTFAAC Brainstorm Meeting, Amsterdam, The Netherlands Eﬃcient Image-based Fast Radio Transient Architecture for the LOFAR-AARTFAAC Project

Jan. 2017 National Radio Science Meeting (URSI), Boulder, CO, USA Enabling Detection of the Epoch of Reionization With Next-generation Radio Instru- ments Dec. 2016 MWA Project Meeting, California Institute of Technology (Caltech), Pasadena, CA, USA

Dec. 2016 Science at Low Frequencies III, California Institute of Technology (Caltech), Pasadena, CA, USA Designing Next-Generation Instruments to Enable Detection of the Epoch of Reionization

Oct. 2016 HERA Collaboration Meeting, MIT, Cambridge, MA, USA Eﬀects of antenna position errors on calibration and EoR power spectrum estimation

Oct. 2016 CALIM 2016, National Radio Astronomy Observatory (NRAO), Socorro, NM, USA E-ﬁeld Parallel Imaging Correlator – A versatile, eﬃcient architecture for modern radio telescopes

Jul. 2016 University of Edinburgh Seminar, University of Edinburgh, Edinburgh, UK Updates on Epoch of Reionization from Current and Future 21cm Experiments

Jun. 2016 Invited Talk, 21cm Cosmology Workshop, University of Cambridge, Cambridge, UK 21cm Cosmology-driven Instrument Design

Jun. 2016 Imperial College Seminar, London, UK Wide-ﬁeld measurements of foregrounds and their role in EoR power spectrum estimators

Jun. 2016 Oxford University Seminar, Oxford, UK Design Guidelines for EoR science with SKA-low and Eﬃcient Scalability of Next- generation Low-frequency Radio Telescopes

Mar. 2016 The Reionization Epoch: New Insights and Future Prospects, Aspen, CO, USA High Precision Wide-ﬁeld Instrument and Foreground Simulations for EoR Experiments

Jan. 2016 Invited Colloquium, National Radio Astronomy Observatory, Socorro, NM, USA E-ﬁeld Parallel Imaging Correlator: An Ultra-eﬃcient Architecture for Modern Radio In- terferometers

Jan. 2016 National Radio Astronomy Observatory Seminar, Socorro, NM, USA Wide-ﬁeld measurements of EoR power spectrum and implications for instrument design

Jan. 2016 National Radio Science Meeting (URSI), Boulder, CO, USA A Generic and Eﬃcient “E-ﬁeld Parallel Imaging Correlator” Software for Next- generation Radio Telescopes

Dec. 2015 MWA Project Meeting, Canada and the Square Kilometre Array, University of Toronto, Toronto, Canada E-ﬁeld Parallel Imaging Correlator: A New Imager for Large-N Arrays

10 of 14 Dec. 2015 MWA Project Meeting, Canada and the Square Kilometre Array, University of Toronto, Toronto, Canada Tackling Foregrounds in Wide-Field EoR Instruments

Dec. 2015 Science at Low Frequencies II, Albuquerque, NM, USA E-ﬁeld Parallel Imaging Correlator: A Novel Imager for Next-generation Radio Telescopes

Oct. 2015 Seminar at University of Washington, Seattle, WA, USA Relevance of a Generic and eﬃcient “E-ﬁeld Parallel Imaging Correlator” (EPIC) for future radio telescopes

Oct. 2015 HERA Simulations Workshop, University of Washington, Seattle, USA

Oct. 2015 Seminar at California Institute of Technology, Pasadena, CA, USA Generic and eﬃcient “E-ﬁeld Parallel Imaging Correlator” (EPIC) for next-generation radio telescopes

Oct. 2015 Seminar at University of California, Los Angeles, CA, USA Lessons for future redshifted 21 cm Epoch of Reionization experiments from modeling and current observations Oct. 2015 Preparing for the 21-cm Cosmology Revolution, University of California, Irvine, CA, USA Decoding the Foreground Devil

Sep. 2015 HERA Workshop, University of California, Irvine, USA

Jun. 2015 Conference on Reionization – A Multi-Wavelength Approach, Kruger Park, South Africa The MWA EoR Experiment: Challenges, Progress, and Future

Mar. 2015 Seminar at National Optical Astronomy Observatory, Tucson, AZ, USA The MWA EoR Experiment: Challenges and Progress

Mar. 2015 Tools for Astronomical Big Data, Tucson, Arizona, USA

Jan. 2015 American Astronomical Society Meeting, Seattle, WA, USA Comparison of Observed and Simulated Reionization Foregrounds from the Murchison Wideﬁeld Array

Dec. 2014 Meeting on Early Science from Low-frequency Radio Telescopes, Tempe, AZ, USA EoR Foreground Simulations: The Devil is in the Details

Dec. 2014 MWA EoR (USA) Project Meeting, Tempe, AZ, USA EoR Foreground Simulations (Quick Summary): The Devil is in the Details

Nov. 2014 HERA Kickoﬀ Meeting, University of California, Berkeley, CA, USA Simulations: EoR and Foregrounds through the HERA Instrument

Oct. 2014 Columbia University Seminar, New York, NY, USA Observed and Simulated Foregrounds for Reionization Studies with the Murchison Wide- ﬁeld Array

Oct. 2014 HERA Kickoﬀ Meeting, University of California, Berkeley, USA

Oct. 2014 MWA EoR (USA) Project Meeting, Cape Cod, Massachusetts, USA

Jul. 2014 Raman Research Institute Seminar, Bangalore, India EoR Foreground Signatures in Delay Space

11 of 14 Jun. 2014 MWA EoR (USA) Project Meeting, University of California, Berkeley, USA EoR Foreground Signatures in Delay Space (Quick Summary)

Dec. 2012 MWA Project Meeting, Geraldton, Australia

Aug. 2012 Joint Indo-South Africa Workshop on Astronomy, Cape Town, South Africa Study of Foregrounds and Limitations to EoR Detection

Jun. 2012 MWA Project Meeting, Bangalore, India Study of Foregrounds and Limitations to EoR Detection

Apr. 2012 National Centre for Radio Astrophysics Seminar, Pune, India Foreground Contamination and the EoR window

Feb. 2012 Curtin University Seminar, Perth, Australia Foreground Contamination and the EoR window

Dec. 2011 MWA Project Meeting, Melbourne, Australia

Jul. 2011 Raman Research Institute Seminar, Bangalore, India Variables and Transients in the VLA FIRST Survey

Dec. 2008 Low Frequency Radio Universe, NCRA, Pune, India A Comprehensive Search for Variables and Transients in the VLA FIRST Survey

Jun. 2006 Summer Synthesis Imaging Workshop, Albuquerque, NM, USA

Jun. 2005 Wide Field Imaging, Dwingeloo, The Netherlands

Jun. 2003 Visiting Summer Research Programme, NCRA, Pune, India

Jun. 2003 Synthesis Imaging school, NCRA, Pune, India

Jun. 2002 Visiting Summer Research Programme, RRI, Bangalore, India

Fellowships and Awards

2017- Jansky Fellow National Radio Astronomy Observatory, Socorro, USA

2011- Pancharatnam Fellow 2013 Raman Research Institute, Bangalore, India

2006- Graduate Research Fellow 2011 Columbia University, New York, NY USA

2004- Faculty Fellow 2006 Columbia University, New York, NY USA

1998- National Talent Search Scholar 2004 Government of India

12 of 14 Teaching

2017 Instructor at the CAMPARE-HERA Astronomy Minority Partnership (CHAMP) Summer 2017 Bootcamp for “Intro. to radio astronomy”, “Interferometry”, and “HERA Walkthrough” courses. 2016- Mentor for research project of graduate student at ASU to explore application of techniques developed for EoR experiments towards Dark Energy detection experiments. Fall 2007 TA for the course Introduction to Astrophysics I for Prof. Kristen Menou. Spring 2007Instructor for lab course Beyond the Solar system. Fall 2006 Instructor for lab course Earth, moon and planets. Spring 2006Instructor for lab course Beyond the Solar system. Fall 2005 Instructor for lab course Earth, moon and planets. Spring 2005TA for lab course Beyond the Solar system. Fall 2004 TA for lab course Earth, moon and planets.

Public Outreach

2013 - ASU Earth & Space Open House, ASU, Tempe, AZ, USA 2011 - 2013 Global Jet Watch project, Partnership between Oxford University and Raman Research Institute, Bangalore, India 2004 - 2011 Columbia University Public Outreach, Columbia University, New York, NY, USA

Professional Service

• Membership in Professional Organizations: International Astronomical Union (Full member), American Astronomical Society (Full member), International Union of Radio Science (Full member) • Scientiﬁc Journal Referee: The Astrophysical Journal, Monthly Notices of the Royal Astro- nomical Society

Undergraduate, Graduate, and Postdoc Advisors

Postdoc Advisor: • Prof. Chris Carilli, National Radio Astronomy Observatory • Prof. Judd Bowman, Arizona State University • Prof. Ravi Subrahmanyan, Raman Research Institute Graduate Advisor: • Prof. David Helfand, Columbia University • Prof. Jacqueline van Gorkom, Columbia University Undergraduate Advisors: • Prof. Harishankar Ramachandran, Indian Institute of Technology (Madras) • Prof. Rajaram Nityananda, National Centre for Radio Astrophysics

13 of 14 Referees

• Prof. Chris L. Carilli, National Radio Astronomy Observatory e-mail: [email protected], phone: +1 (575) 835-7306

• Prof. Judd D. Bowman, Arizona State university e-mail: [email protected], phone: +1 (480) 965-8880

• Prof. Aaron R. Parsons, University of California, Berkeley e-mail: [email protected], phone: +1 (510) 406-4322

• Prof. Ravi Subrahmanyan, Raman Research Institute e-mail: [email protected], phone: +91 (80) 23611012

• Prof. David J. Helfand, Columbia University e-mail: [email protected], phone: +1 (212) 854-2150

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