Janik Karoly

Publications

See full list of my publications on ADS

The JCMT BISTRO Survey: Magnetic Fields Align with Orbital Structure in the Galactic Center
Janik Karoly, Derek Ward-Thompson, Kate Pattle and the BISTRO Consortium. 2025, The Astrophysical Journal Letters, 982, 22. doi: 10.3847/2041-8213/adbc67

Karoly et al, 2025.

The JCMT BISTRO Survey: Unveiling the Magnetic Fields around Galactic Center
Meng-Zhe Yang, Shih-Ping Lai, Janik Karoly and the BISTRO Consortium. 2025, The Astrophysical Journal, Accepted. doi: 10.48550/arXiv.2503.05198

Submillimeter-wavelength Polarimetry of IRC+ 10216
B-G Andersson, Janik Karoly, Pierre Bastien, et al. 2023, The Astrophysical Journal, 963, 76. doi: 10.3847/1538-4357/ad1835

The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
Janik Karoly, Derek Ward-Thompson, Kate Pattle and the BISTRO Consortium. 2023, The Astrophysical Journal, 952, 29. doi: 10.3847/1538-4357/acd6f2

High Resolution Observations of HI in the IC 63 Reflection Nebula
Lars Bonne, B-G Andersson, Robert Minchin, et al. 2023, The Astronomical Journal, 165, 243. doi: 10.3847/1538-3881/accf85

Ward-Thompson et al, 2023.

First BISTRO Observations of the Dark Cloud Taurus L1495A-B10: The Role of the Magnetic Field in the Earliest Stages of Low-mass Star Formation
Derek Ward-Thompson, Janik Karoly, Kate Pattle and the BISTRO Consortium. 2023, The Astrophysical Journal, 946, 62. doi: 10.3847/1538-4357/acbea4

Spatial Variation in Temperature and Density in the IC 63 PDR from H2 Spectroscopy
Archana Soam, B-G Andersson, Janik Karoly, et al. 2021, The Astrophysical Journal, 923, 107. doi: 10.3847/1538-4357/ac2eb7

The JCMT BISTRO-2 Survey: The Magnetic Field in the Center of the Rosette Molecular Cloud
Vera Konyves, Derek Ward-Thompson, Kate Pattle and the BISTRO Consortium. 2021, The Astrophysical Journal, 913, 57. doi: 10.3847/1538-4357/abf3ca

Revisiting the Magnetic Field of the L183 Starless Core
Janik Karoly, Archana Soam, B-G Andersson, et al. 2020, The Astrophysical Journal, 900, 181. doi: 10.3847/1538-4357/abad37

Measurements of magnetic field structure and strength in a starless core L183
Janik Karoly, Archana Soam, B-G Andersson, Simon Coude, Pierre Bastien. 2020. AAS Conf #235. iPoster

Karoly et al, 2020.

Work

Magnetic field in rho Ophiuchus A visualized by the Line Integral Convolution method.

I study the role of interstellar magnetic fields in the early stages of star formation. I do this across a range of scales, from studying individual molecular clouds and cores in nearby star-forming regions such as Ophiuchus and Taurus all the way to the distant center of our galaxy. The formation of filaments, molecular clouds and eventually stellar cores is mediated by many processes, most notably of course being gravity. However, the roles of magnetic field and turbulence also play important roles.

SCUBA-2 with POL-2 inserted in front of the detector.
Credit: East Asian Observatory

To study the magnetic fields, we rely on telescopes like the James Clerk Maxwell Telescope (JCMT) and its instruments such as the Submillimetre Common User Bolometer Array 2 (SCUBA-2) and its associated polarimeter POL-2. This allows us to study polarised light from distant star forming regions that has been emitted by dust particles. The dust particles are aligned with the local magnetic field via a mechanism called Radiative Alignment Torque (RAT) theory. We can therefore infer the magnetic field direction in these molecular clouds by rotating the polarisation vectors by 90 degrees since the light is polarised along the dust grains larger axis for emission polarimetry and the grains are aligned with the magnetic field along their short axis. We are still working to better understand this mechanism and many caveats have been suggested over the years, but the general mechanism is still believed to hold.

Visiting the JCMT. The 15m dish sits behind the Gore-Tex membrane.

I am currently a member of the JCMT Large Program, B-fields In STar-forming Regions Observations (BISTRO) and the ALMA survey Magnetic Fields in Massive Star-forming Regions (MagMaR). I am also a member of the ALMA CMZ Exploration Survey (ACES). I primarily use data from the JCMT as well as from the Atacama Large Millimetre Array (ALMA) in Chile and the (now sadly retired) Stratosferic Observatory For Infrared Astronomy (SOFIA). I also use archival Planck, Herschel and Spitzer data.

About

Visiting the summit of Mauna Kea and the JCMT in September 2023.

I received my Bachelors of Science from Santa Clara University in Santa Clara, CA in 2020. I graduated with a major in Physics and minors in Math and Political Science, but have always been interested in pursuing astrophysics. I started my PhD at the University of Central Lancashire (now University of Lancashire) in Preston, UK in September 2020, working under Professor Derek Ward-Thompson, and submitted my thesis, titled "The Role of Magnetic Fields Across Different Scales in the Early Stages of Star Formation," in March 2024. I also worked for two summers at the Universities Space Research Association (USRA) at the SOFIA Science Center at NASA Ames in California under Drs. B-G Andersson and Archana Soam. As of April 2024, I have started a 2-year postdoctoral research associate position at the University College London, working with Dr. Kate Pattle.

In addition to studying astrophysics, I enjoy spending as much of my time outdoors as possible. I enjoy rock climbing and playing soccer as well.

Contact

Feel free to reach out to me directly at: j.karoly at ucl.ac.uk

LinkedIn
• LinkedIn

GitHub
• GitHub

ORCiD

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