2006 Fiscal Year Final Research Report Summary
ELUCIDATION OF ORIGINS OF STELLAR MASS WITH WIDE FIELD IR SURVEYS: IMF IN STAR FORMATION
| Project/Area Number |
16340061
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory of Japan (NAOJ) |
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Principal Investigator |
TAMURA Motohide NAOJ, OPT/IR DIV., ASSOC. PROF., 光赤外研究部, 助教授 (00260018)
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| Co-Investigator(Kenkyū-buntansha) |
NAGATA Tesuya TYOTO UNIV., SCIENCE, PROF., 大学院理学研究科, 教授 (80208016)
SATO Shuji NAGOYA UNIV., SCIENCE, PROF., 大学院理学研究科, 教授 (50025483)
HAYASHI Masahiko NAOJ, OPT/IR DIV, PROF., 光赤外研究部, 教授 (10183914)
SUTO Hiroshi NAOJ, OPT/IR DIV, ASSISTANT PROF., 光赤外研究部, 主任研究員む (50300710)
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| Project Period (FY) |
2004 – 2006
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| Keywords | INFRARED / STAR FORMATION / BROWN DWARF / MASS FUNCTION / MOLECULAR CLOUD / POLARIZATION / VARIABILITY |
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| Research Abstract |
This research aims to establish the initial mass function (IMF) of stars, including very low-mass stars such as brown dwarfs and even planetary mass objects. In order to this, we have conducted very wide field infrared surveys of star forming regions. Since infrared surveys can uncover the embedded stellar clusters whose mass distribution reflects the IMF. In addition, because the young stars are relatively bright at infrared due to their gravitational energy, we can detect down to very low mass stars. We can distinguish young stars from background stars taking into account their color and polarization information. The mains results are summarized as follows:
(1)We conducted observations of nearby star forming regions. with the IRSF 1.4m telescope in South Africa, the Subaru and Gemini telescopes in Hawaii. Those at IRSF were conducted with the SIRIUS JHKs-band simultaneous camera, which was developed by NAOJ and Naoya University. The observed regions are Oph, Cha, R CrA, Orion, Vela, Cygnus molecular clouds. We have detected a number f new brown dwarfs and planetary mass candidates in some regions. The results for Orion, S106, and Vela regions were already published in refereed journals. We have discovered the universality of brown dwarfs and the relative populations of very low mass stars to low mass stars vary from region to region.
(2)We discovered the middle mass young stars in the Magellanic Bridge (published in refereed journal).
(3)We developed wide field infrared polarimeter for IRSF/SIRIUS and conducted polarization observations. We detected a number of new circumstellar structures.
(4)We conducted photometry and spectroscopy of the Oph cloud core and found lowest mass candidates.
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