Kei E. I. Tanaka

Assistant Professor
Department of Earth and Planetary Sciences
Institute of Science Tokyo

Welcome to my page!

I’m an astronomer studying the birth of stars and planets

Recent Topics

• Jul 13, 2026: Paper Published! Yang, Zhang, Tanaka et al. 2026, ApJ
  Our paper from the HOTDISK project has been published. Using high-resolution ALMA observations of 10 massive protostars, we detected compact rotating structures in seven sources. We demonstrated that high-excitation water vapor, NaCl, and SiS lines are powerful tracers of disks and revealed that hot-disk chemistry is widespread in massive star-forming regions.

• Jun 16, 2026: ngVLA International Science Conference 2026 registration is now open!
  Registration and abstract submission are now open for the ngVLA International Science Conference 2026, which will be held in Sendai, Japan, on November 10-13, 2026. The meeting will bring together researchers to discuss science enabled by the next-generation Very Large Array. The abstract submission deadline for oral presentations and financial support is July 31, 2026.

• May 22, 2026: Paper Published! Meng et al. 2026, ApJ
  Our paper from the INFANT survey has been published. Focusing on the massive star-forming filament I19368, we reveal a dynamic scenario for high-mass star formation, where turbulence-driven hierarchical fragmentation coexists with gravity-driven multiscale gas infall.

• Mar 9, 2026: Paper Published! Luo et al. 2026, ApJ
  Our paper on low-mass multiples in high-mass cluster-forming regions has been published. ALMA observations reveal a characteristic separation of ~1200 au, suggesting turbulent core fragmentation.

• Mar 3, 2026: Paper Published! Ikeda et al. 2026, ApJ
  Our paper on the hot molecular core Sh2-283 in the outer Galaxy has been published. We detected complex organic molecules and investigated chemical complexity in low-metallicity star-forming environments.

• Feb 26, 2026: Paper Published! Olguin et al. 2026, ApJ
  Our paper from the ALMA DIHCA survey has been published. We identified 32 disk candidates around high-mass protostars and found evidence for anisotropic infall feeding massive star formation.

• Feb 16, 206: Paper Published! Mondal et al. 2026, ApJ
  Our paper on ALMA observations of the N79 South giant molecular cloud in the Large Magellanic Cloud has been published. We detected cold methanol gas associated with dense cores, providing new insights into organic molecule formation in a low-metallicity environment.

• Feb 3, 2026: Paper Published! Shimonishi, Tanaka et al. 2026, ApJS
  Our MAGOS (Magellanic Outflow and Chemistry Survey) paper on hot cores in the Large Magellanic Cloud has been published. Using ALMA observations of 30 massive protostellar objects, we identified multiple hot cores and detected complex organic molecules, providing new insights into hot-core chemistry in low-metallicity environments. 

• Jan 6, 206:  Paper Published! Sequeira-Murillo et al. 2026, ApJ
  Our paper from the SOFIA Massive (SOMA) Star Formation Survey has been published. Using VLA and ATCA observations, we investigated radio continuum emission from high-luminosity massive protostars and identified several ionized jet candidates.

• Dec 22, 2025: Our paper on the SOMA Survey was featured on AAS Nova!

• Dec 15, 2025:  Paper Published! Guo et al. 2025, A&A
  Our paper from the ALMA INFANT survey has been published. We reported the multi-scale structure and hierarchical fragmentation of the massive star-forming filament IRAS 19074+0752.

• Oct 1, 2025: Suinan Zhang joined Science Tokyo as an ALMA Project Assistant Professor!
  She has joined our team through the ALMA Joint Scientific Research Program by NAOJ ALMA. Welcome, Suinan!

• Sep 26, 2025: Adam Ginsburg joined Science Tokyo as a Visiting Associate Professor!
  He has joined our team through the WRH Program by Science Tokyo. Welcome, Adam!

• Sep 10, 2025: Press Release! "NASA’s Webb Observes Immense Stellar Jet on Outskirts of Our Milky Way"
  Our recent paper on the LZ-STAR survey of Sh2-284 was press released from NASA JWST. The JWST image shows an immense stellar jet extending over 8 light-years, providing striking evidence of ordered massive star formation in the outer Galaxy.

• Sep 10, 2025: Paper Published! Cheng et al. 2025, ApJ
  Our paper on the LZ-STAR survey of the low-metallicity region Sh2-284 has been published. Using JWST and ALMA, we reported ordered massive star formation with large bipolar outflows in one of the lowest-metallicity star-forming regions of our Galaxy.

• Aug 25, 2025: Paper Published! Yamamuro et al. 2025, ApJ
  We developed a self-consistent model of grain growth and millimeter-wave emission in massive protostellar disks. A comparison with ALMA observations suggests that silicate grain coagulation may be suppressed in these high-temperature environments.

• Aug 20, 2025: Paper Published! Olguin et al. 2025, Sci. Adv
  Our paper on ALMA observations of the massive star-forming region G336.01 has been published. We discovered massive extended streamers feeding a massive protostar, providing direct evidence of large-scale inflows that sustain its growth.

• Aug 4, 2025: Paper Published! Zhen et al. 2025, A&A
  Our paper on ALMA observations of the massive star-forming region I18308 has been published. We revealed hierarchical fragmentation in a hub-filament system, linking large-scale structures to the formation of massive stars.

• July 29, 2025: Press Release! “Discovery of Protostellar Outflows in the Outer Galaxy – Approaching the Universality of Star Formation in the Outer Milky Way”
  The press release on our recent paper was issued from Niigata Univ (Japanese only).

• July 17, 2025: Paper Published! Ikeda et al. 2025, ApJ
  Our paper on ALMA observations of a protostar in the outer Galaxy has been published. We reported the first detection in this region of a well-collimated jet accompanied by a wider molecular outflow.