Large-scale CO (J=4–3) mapping toward the Orion-A giant molecular cloud
Author
dc.contributor.author
ISHII, Shun
Author
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Seta, Masumichi
Author
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Nagai, Makoto
Author
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Miyamoto, Yusuke
Author
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Nakai, Naomasa
Author
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Nagasaki, Taketo
Author
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Arai, Hitoshi
Author
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Imada, Hiroaki
Author
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Miyagawa, Naoki
Author
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Maezawa, Hiroyuki
Author
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Maehashi, Hideki
Author
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Finger Camus, Ricardo
Admission date
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2016-11-25T12:30:47Z
Available date
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2016-11-25T12:30:47Z
Publication date
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2015
Cita de ítem
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Publ. Astron. Soc. Japan (2016) 68 (1), 10 (1–13)
es_ES
Identifier
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10.1093/pasj/psv116
Identifier
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https://repositorio.uchile.cl/handle/2250/141464
Abstract
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We have mapped the Orion-A giant molecular cloud in the CO(J=4–3) line with the
Tsukuba 30cm submillimeter telescope. The map covered a 7.125 deg2 area with a 9
resolution, including main components of the cloud such as the Orion Nebula, OMC-
2/3, and L1641-N. The most intense emission was detected toward the Orion KL region.
The integrated intensity ratio between CO(J=4–3) and CO(J=1–0) was derived using
data from the Columbia–Universidad de Chile CO survey, which was carried out with
a comparable angular resolution. The ratio was r4−3/1−0 ∼0.2 in the southern region of
the cloud and 0.4–0.8 at star forming regions. We found a trend that the ratio shows
higher values at the edges of the cloud. In particular, the ratio at the northeastern edge
of the cloud at (l, b) ≈ (208. ◦ 375, −19. ◦ 0) shows the highest value of 1.1. The physical
condition of the molecular gas in the cloud was estimated by non-LTE calculation. The
result indicates that the kinetic temperature has a gradient from north (Tkin = 80 K) to
south (20 K). The estimation shows that the gas associated with the edge of the cloud is
warm (Tkin ∼60 K), dense (nH2∼ 104 cm−3), and optically thin, which may be explained by
heating and sweeping of interstellar materials from OB clusters.