Education and Positions

• Associate Research Fellow, ASIAA (2005~present)
• Odin Project Scientist, Univ. Calgary (1998~2005)
• Research Associate, St. Mary’s Univ. (1992~1996)
• Research Associate, Ohio State Univ. (1991~1992)
• Research Associate, Duke University (1990~1991)
• Postdoctoral Fellow, St. Mary’s Univ. (1988~1990)
• Postdoctoral Fellow, CITA (1986~1988)
• Ph.D., Astronomy, Tohoku University (1984)
• M.S., Astronomy, Tohoku University (1978)

Research Interests

Molecular Astrophysics – (a) Theoretical studies of chemistry in interstellar clouds and circumstellar envelopes. (b) Observational studies in the submillimeter band of abundances of various molecules in space.

Based on a database of a few thousand chemical reactions, my program generates a computer code that estimates the rates of formations and destructions of hundreds of molecular species. The computer simulations with such a chemical code are compared with observations of molecules in interstellar clouds. Observations of molecular lines are translated to the amounts of the emitting molecules through calculations of molecular excitations by collisions and radiation. Important chemical processes are identified after finding a best match between observations and chemical simulations for an astronomical object. The figures show distributions of thin layers of peculiar molecules in a region illuminated by a hot star.

My activities also include radio observations of the molecules. I have been a frequent visitor to Mauna Kea (Hawaii) for observations for twenty years. Most observations these days are carried out in a remote or queue (automated) mode.

Journal Papers affiliated with ASIAA

1. ALMA Partnership; Fomalont EB; Vlahakis C; ...; Matsushita S; …; Espada D.; …; Chapillon E; ...; Hasegawa T; ...; Ohashi N; ...; Huang Y-D; Liu S-Y; Kemper F; Koch PM; Chen M-T; ...; Su Y-N; Trejo-Cruz A; Wang K-S; ...; Ho PTP; et al., "The 2014 ALMA Long Baseline Campaign: An Overview" , ApJL: 808(1), L1, July 20, 2015 [SCI] ( ADS | Fulltext )
2. Motoyama K; Morata O; Shang H; Krasnopolsky R; Hasegawa T, "A hydrochemical hybrid code for astrophysical problems. I. Code verification and benchmarks for Photon-Dominated Region (PDR)" , ApJ: 808(1), 46, July, 2015 [SCI] ( ADS | Fulltext )
3. He J-H; Szczerba R; Hasegawa TI; Schmidt MR, "Observed Relationship between CO 2-1 and Dust Emission during the Post-asymptotic-giant-branch Phase" , ApJS: 210(2), 26, Feb, 2014 [SCI] ( ADS | Fulltext )
4. Mispelaer F; Theulé P; Aouididi H; ...; Morata O; Hasegawa TI; et al., "Diffusion measurements of CO, HNCO, H2CO, and NH3 in amorphous water ice" , A&A: 555, A13, July, 2013 [SCI] ( ADS | Fulltext )
5. Morata O;Hasegawa TI, "Effects of H2 coating of grains on depletion of molecular species" , MNRAS: 429(4), 3578-3583, March 11, 2013 [SCI] ( ADS | Fulltext )
6. Motoyama K; Umemoto T; Shang H; Hasegawa T, "Effects of Magnetic Field and Far-ultraviolet Radiation on the Structures of Bright-rimmed Clouds" , ApJ: 766(1), 50, Mar 20, 2013 [SCI] ( ADS | Fulltext )
7. Huang ZY; Hasegawa TI; Trung DV; Kwok S; Muller S; Hirano N; Lim J; Muthu C; Lyo A, "Detection of Multiple Bipolar Flows in NGC 7027 with Submillimeter Array" , ApJ: 722(1), 273-280, Oct 10, 2010 [SCI] ( ADS | Fulltext )
8. Lee CF; Hasegawa TI; Hirano N; Palau A; Shang H; Ho PTP; Zhang Q, "The Reflection-Symmetric Wiggle of the Young Protostellar Jet HH211" , ApJ: 713(2), 731-737, April 20, 2010 [SCI] ( ADS | Fulltext )
9. He JH; Dinh-V-Trung; Kwok S; ...; Hasegawa TI; et al., "A spectral line survey in the lambda 2 and lambda 1.3mm windows toward the carbon rich envelope of IRC +10216." , ApJS: 177(1), 275-325, July, 2008 [SCI] ( ADS | Fulltext )
10. He JH; Imai H; Hasegawa TI; Campbell SW; et al., "First detection of CO lines towards a water fountain star." , A&A: 488(2), L21-L24, Sep, 2008 [SCI] ( ADS | Fulltext )
11. Wang M-Y; Hasegawa TI; Kwok S, "The Detection of a Molecular Bipolar Flow in the Multipolar Planetary Nebula NGC 2440" , ApJ: 673(1), 264-270, Jan 20, 2008 [SCI] ( ADS | Fulltext )
12. Larsson B; Liseau R; Pagani L;...; Hasegawa T; ...; Kwok S; et al., "Molecular oxygen in the rho Ophiuchi cloud" , A&A: 466(3), 999-1003, May, 2007 [SCI] ( ADS | Fulltext )
13. Manoj P; Ho PTP; Ohashi N; Zhang Q; Hasegawa T; Chen HR; Bhatt HC; Ashok NM, "An evolved disk surrounding the massive main sequence star MWC 297?" , ApJ: 667(2), L187-L190, Oct 1, 2007 [SCI] ( ADS | Fulltext )
14. Nakashima J; Fong D; Hasegawa T; Hirano N; Koning N; Kwok S; Lim J; Dinh-Van-Trung; Young K, "Submillimeter Array Observation of the Proto-Planetary Nebula CRL 618 in the CO J = 6-5 Line" , AJ: 134(5), 2035-2045, Nov, 2007 [SCI] ( ADS | Fulltext )
15. Olofsson AOH; Persson CM; Koning N; ...; Hasegawa T; et al., "A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite - I. The observational data" , A&A: 476(2), 791-806, Dec, 2007 [SCI] ( ADS | Fulltext )
16. Persson CM; Olofsson AOH; Koning N; Hasegawa TI; et al., "A spectral line survey of Orion KL in the bands 487-492 and 541-577 GHz with the Odin satellite - II. Data analysis" , A&A: 476(2), 807-827, Dec, 2007 [SCI] ( ADS | Fulltext )
17. Hasegawa TI; Kwok S; Koning N; Volk K; Justtanont K; Olofsson H; Schoeier FL; Sandqvist Aa; Hjalmarson A; Olberg M; Winnberg A; Nyman L-A; Frisk U, "Observations of the Circumstellar Water 110-->101 and Ammonia 10-->00 Lines in IRC +10216 by the Odin Satellite" , ApJ: 637(2), 791-797, Feb 1, 2006 [SCI] ( ADS | Fulltext )