John F Wardle

Professor of Astrophysics

wardle@brandeis.edu
781-736-2889
Abelson-Bass-Yalem Building, 328

Departments/Programs

Physics

Degrees

University of Manchester, Ph.D.
University of Cambridge, M.A.
University of Manchester, M.S.
University of Cambridge, B.A.

Expertise

Radio astronomy. Cosmology. High energy astrophysics. Extragalactic radio sources. Quasars. Active Galactic Nuclei. X-ray astronomy. Supermassive Black Holes. The Event Horizon Telescope

Profile

My research concerns observational and theoretical studies of the powerful jets which are seen to shoot out at close to the speed of light from the hearts of active galaxies and quasars, and also from some x-ray binary systems (dubbed “micro-quasars”) within our own Galaxy. These are thought to originate from the vicinity of black holes that range in mass from ten to ten billion times the mass of the Sun.
I am also a member of the Event Horizon Telescope Collaboration which images the event horizon of nearby supermassive black holes. On April 10 2019, we announced and presented the first ever image of the event horizon of a black hole (the supermassive black hole in the center of the galaxy M87. For this, the entire collaboration was awarded the $3M 2019 "Breakthrough Prize in Fundamental Physics."

Courses Taught

PHSC	2b	Introductory Astronomy
PHYS	20a	Waves and Oscillations
PHYS	91g	Introduction to Research Practice
PHYS	108b	Astrophysics
PHYS	168b	Introduction to Astrophysics

Awards and Honors

Royal Astronomical Society Group Achievement Award Presented to EHT collaboration (2021)

Breakhrough Prize in Fundamental Physics (2019)

Guggenheim Foundation Fellowship (1994 - 1995)

Fellow, Royal Astronomical Society (1970)

Scholarship

Wardle, John F, with Snios, Bradford; Schwartz, Daniel, et al. "Discovery of Candidate X-ray Jets in High-Redshift Quasars." arXiv210212609S (astro-ph) (2021). (forthcoming)

Akiyama, K., and The Event Horizon Telescope Collaboration.. "First M 87 Event Horizon Telescope results VII: The polarization of the Ring." Astrophysical Journal Letters (in press) (2021): pp 53.

Akiyama, K., and The Event Horizon Telescope Collaboration.. "First M87 Event Horizon Telescope Results VIII: Magnetic Field Structure Near The Event Horizon." Astrophysical Journal Letters (in press) (2021): pp 27.

Wardle, John F with Algaba, J.-C. and the Event Horizon Telescope collaboration. "Broadband Multi-wavelength Properties of M87 During the 2017 Event Horizon Telescope Campaign." Astrophysical Journal Letters (in press) (2021).

Wardle, John F, wih Goddi, C. and the Event Horizon Telescope collaboration. "Polarimetric properties of event horizon telescope targets from ALMA." Astrophysical Journal Letters (in press) (2021).

Wardle, John F with Wielgus, Maciek, and the Event Horizon Telescope Collaboration. "Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope." Astrophysical Journal 901. (2020): pp 67-105.

Wardle, John F, with Freek Roelefs and the Event Horizon Telescope Collaboration. "SYMBA: An end to end VLBI synthetic data generation pipeline, smulating Evenet Horizon Telescope observations of M87." Astronomy and Astrophysics 636. (2020): pp 5-25.

Wardle, John F, with Maithil, Jaya, et al. "Investigating Orientation Effects Considering Angular Resolution for a Sample of Radio-loud Quasars Using VLA Observations." Astrophysical Journal 904. (2020): pp 179-219.

Wardle, John F, with Psaltis, D, and the Event Horizon Telescope Collaboration. "Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole." Physical Review Letters 125. (2020): pp 1104-1114.

Wardle, John F, with Schwartz, D. A., Siemiginowska, A, et al.. "Two Candidate High-redshift X-Ray Jets without Coincident Radio Jets." Astrophysical Journal 904. (2020): pp 57-64.

Wardle, John F, with Worrall, D. M.; Birkinshaw, M.; Marshall, H. L.; Schwartz, D. A.; Siemiginowska, A.;. "Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421-0643." Monthly Notices of the Royal Astronomical Society 497. (2020): pp 998-1000.

Wardle, John F, with the Event Horizon Telescope Collaboration. "Event Horizon Telescope imaging of the archtypal blazar 3C279 at an extreme 20 microarcsecond resolution." Astronomy and Astrophysics 640. (2020): pp 69 - 92.

Wardle, John F; Avery Broderick, with the Event Horizon Telescope Collaboration. "THEMIS: A Parameter Estmation Framework for the Event Horizon Telescope." Astrophysical Journal 897. (2020): pp 193 - 230.

Wardle, John F; Roman Gold, and the Event Horizon Telescope Collaboration. "Verification of Radiative Transfer Schemes for the EHT." Astrophysical Journal 897. (2020): pp148-170.

Wardle, John; with Chael, Andrew A.; Bouman, Katherine L.; et al.. "ehtim: Imaging, analysis, and simulation software for radio interferometry." Astrophysics Source Code Library 1904.004. (2020).

Wardle, John; with Porth, O.; Chatterjee, K.; Narayan, R. et al.. "The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project." Astrophysical Journal Supplememnt Series 243. 2 (2020): 40.

Akiyama, K., and The Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results I: The shadow of the central black hole." Astrophysical Journal Letters 875. L1 (2019): 16 pages.

Akiyama, K., and The Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results II: Array and instrumentation." Astrophysical Journal Letters 875. 1, L2 (2019): 30 pages.

Akiyama, K., and The Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results III: Data processing and calibration." Astrophysical Journal Letters 875. 1, L3 (2019): 32 pages.

Akiyama, K., and The Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results IV: Imaging the central supermassive black hole." Astrophysical Journal Letters 875. 1, L4 (2019): 52 pages.

Akiyama, K., and The Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results VI: The shadow and mass of the central black hole." Astrophysical Journal Letters 875. 1, L6 (2019): 49 pages.

Akiyama, K.: and theThe Event Horizon Telescope Collaboration. "First M 87 Event Horizon Telescope results V: Physical origin of the ring-like structure of the central black hole." Astrophysical Journal Letters 875. 1, L5 (2019): 34 pages.

Schwartz, Daniel A; Siemiginowska, Aneta; Worrall, Diana M; Birkinshaw, Mark; Cheung, Teddy; Marshall, Herman; Migliori, Guilia; Wardle, John; Gobeille, Doug. "Relativistic X-ray jets at high redshift." arXiv e-print :1901.00057 (2019): 6.

Wardle, John FC et al. "Detecting Relativistic X-Ray Jets in High-redshift Quasars." Astrophysical Journal 823. (2018): 123 - 144.

Wardle, John FC. "The Variable Rotation Measure Distribution in 3C 273 on Parsec Scales." Galaxies 6. 1 (2018): 5-15.

Andrew Chael, Michael Johnson, Ramesh Narayan, Shepherd Doeleman, John Wardle, Katherine Bouman. "“High Resolution Linear Polarimetric Imaging for the Event Horizon Telescope”." accepted for publication in The Astrophysical Journal (2016) (2016).

Fish, Vincent L.; Johnson, Michael D.; Doeleman, Sheperd S.; Broderick, Avery E.; Psaltis, Dimitrios; Lu, Ru-Sen; Akiyama, Kazunori; Alef, Walter; Algaba, Juan Carlos; Asada, Keiichi; and 62 coauthors. "“Persistent Asymmetric Structure of Sagittarius A* on Event Horizon Scales”." The Astrophysical Journal Vol 820. (2016): pp 90-101.

Johnson, Michael D.; Fish, Vincent L.; Doeleman, Sheperd S.; Marrone, Daniel P.; Plambeck, Richard L.; Wardle, John F. C.; Akiyama, Kazunori; Asada, Keiichi; Beaudoin, Christopher; Blackburn, Lindy; and 38 coauthors,. "“Resolved magnetic-field structure and variability near the event horizon of Sagittarius A*”." Science Vol 350. Issue 6265 (2016): pp 1242-1245.

Gobeille, Doug B.; Wardle, John F. C.; Cheung, C. C.. "VLA Observations of a Complete Sample of Radio Loud Quasars between redshifts 2.5 and 5.28: I. high-redshift sample summary and the radio images." eprint arXiv:1406.4797, (2015): 31 pages.

Johnson, Michael D.; Fish, Vincent L.; Doeleman, Sheperd S.; Broderick, Avery E.; Wardle, John F. C.; Marrone, Daniel P.,. "Relative Astrometry of Compact Flaring Structures in Sgr A* with Polarimetric Very Long Baseline Interferometry." Astrophys. J. 794. (2015): pp 150-157.

K.J. Van Gorkom*, J.F.C. Wardle, A.P. Rauch and D.B. Gobeille (* indicates undergraduate author). "Comparing Different Indicators of Quasar Orientation." Mon. Not. Roy. Astr. Soc. Vol 450,. (2015): pp 4240-4247.

Wardle, John FC, Ivan Agudo and 21 coauthors. "Studies of Relativistic Jets in Active Galactic Nuclei with SKA." eprint arXiv:1501.00420, in Conference Proceedings "Advancing Astrophysics with the Square Kilometre Array (AASKA14). 9 -13 June, 2014. Giardini Naxos, Italy (2015).

Wardle, John FC. "Magnetic fields and polarization in AGN jets." Invited review at "The Innermost Regions of Relativistic Jets and Their Magnetic Fields,", Granada, Spain. EPJ Web of Conferences, Volume 61, id.06001, Edited by José L. Gómez;, December 2013.

Wardle, John FC (with Roberts, D. H. & Marchenko, V. V.). "The Structure and Linear Polarization of the Kiloparsec-scale Jet of the Quasar 3C 345." Astronomical Journal 145. (2013): 49-58.

Wardle, John FC, with Vincent Fish et al.,. "High-Angular-Resolution and High-Sensitivity Science Enabled by Beamformed ALMA." astro-ph eprint arXiv:1309.3519. (2013)

Wardle, John FC (with Cheung, C. C.; Stawarz, Ł.; Siemiginowska, A.; Gobeille, D.; Harris, D. E.; Schwartz, D. A.). "Discovery of a Kiloparsec-scale X-Ray/Radio Jet in the z = 4.72 Quasar GB 1428+4217." Astrophysical Journal 756. (2012): L20-L24.

Wardle, John FC (with Roberts, D. H.). "Evidence for Highly Relativistic Velocities in the Kiloparsec-scale Jet of the Quasar 3C 345 Authors: ." Astrophysical Journal 749. (2012): L35-L39.

Wardle, John FC (with M. R. Bell and D. R. Roberts). " Structure and Magnetic Fields in the Precessing Jet System SS433 III. Evolution of the Intrinsic Brightness of the Jets from a Deep Multi-Epoch VLA Campaign." Astrophysical Journal 736. 2 (2011): 118-132.

Wardle, John FC (with David H. Roberts, Michael R. Bell, Matthew R. Mallory, Valerie Marchenko, Phoebe Sanderbeck). "Structure and Magnetic Fields in the Precessing Jet System SS 433 II. Intrinsic Brightness of the Jets." Astrophysical Journal, 719, pp1918 - 1925 (2010).

Wardle, John FC with D. Homan, M. Lister, H. Aller, M. Aller. "Full Polarization Spectra of 3C 279." Astrophysical Journal (2009).

Wardle, John FC, with Roberts, David H.; Lipnick, Scott L.; Selesnick, Philip L.; Slutsky, Simon;. "Structure and Magnetic Fields in the Precessing Jet System SS 433. I. Multifrequency Imaging from 1998." Astrophysical Journal 676. (2008): 585-593.

Wardle, John FC with Cheung, C. C.; Stawarz, L.; Siemiginowska, A.; Harris, D. E; Schwartz, D. A.; Gobeille, D.; Lee, N. P.;. "The Highest Redshift Relativistic Jets." Extragalactic Jets: Theory and Observation from Radio to Gamma Ray, Girdwood, Alaska. Eds. T.A. Rector and D.S. De Young, 21-24 May (2007).

Wardle, John FC with Cheung, C. C.; Lee, N. P.. "Large-Scale Radio and X-ray Jets in the Highest Redshift Quasars." 22nd Texas Symposium on Relativistic Astrophysics, Eds. P. Chen et al. also arXiv:astro-ph/0606256. (2006).

Wardle, John FC with Sambruna, Rita M.; Gliozzi, Mario; Donato, Davide; Maraschi, L.; Tavecchio, F.; Cheung, C. C.; Urry, C. Megan. "Deep Chandra and Multicolor HST Follow-up of the Jets in Two Powerful Radio Quasars." Astrophysical Journal 641. 2 (2006): 717-731.

Wardle, John FC with Tavecchio, F.; Maraschi, L.; Sambruna, R. M.; Gliozzi, M.; Cheung, C. C.; Urry, C. Megan,. "Deceleration from Entrainment in the Jet of the Quasar 1136-135?." Astrophysical Journal 641. 2 (2006): 732-739.

Wardle, John FC, with Attridge, Joanne M.; Wardle, Homan, D. C.. "Concurrent 43 and 86 GHz Very Long Baseline Polarimetry of 3C 273." Astrophysical Journal 628. 1 (2005): 104-112.

Wardle,John FC with C Cheung & T Chen. "Optical detections of the radio hotspots in three powerful 3CR quasars." Astrophysical Journal (2005).

Wardle,John FC with D. Homan. "High levels of circulary polarized emission from the raido jet in NGC 1275 (3C84)." Astrophysical Journal 602. 13 (2004).

Wardle,John FC with R Ojha, D Homan, D. Roberts, M Aller H Aller & P Hughes. "Parsec scale blazar monitoring: the data." Astrophys. J. Supplement 150. 187 (2004).

Wardle,John FC with Z Paragi, R Vermeulen, D Homan, I Fejes, R Schillizzi, R Spencer & A Stirling. Probing the polarization characteristics of SS433 on mas scales. Proc 7th Symposium on the European VLBI network and astro_ph/0412682, 2004.