Abstract
The 3P2-3P1 fine-structure line of the neutral carbon atom (809 GHz) has been observed toward the Orion Kleinmann-Low (KL) region with the Mount Fuji submillimeter-wave telescope. The 6′ × 6′ area centered at Orion KL has been mapped with a grid spacing of 1′.5. The intensity distribution of the 3P2-3P1 line is found to be similar to that of the 3P1-3P0 line; these lines are rather weak toward Orion KL, while they are both bright at Orion KL's northern and southern positions. The excitation temperature determined from the intensity ratio between the 3P2-3P1 and 3P1-3P0 lines ranges from 40 to 110 K. The excitation temperature is not enhanced toward Orion KL, whereas it tends to be high in the vicinity of θ1 Orionis C. These results indicate that the C I emission arises from a photodissociation surface illuminated by strong UV radiation from θ1 Ori C. The relative reduction in the C I intensities toward Orion KL is found to originate from a relatively low excitation temperature rather than from the depletion of the C I column density. The origin of the low-excitation temperature of C I toward Orion KL is discussed in terms of a radiative transfer effect.
| Original language | English |
|---|---|
| Journal | Astrophysical Journal |
| Volume | 547 |
| Issue number | 2 PART 2 |
| DOIs | |
| Publication status | Published - 2001 Feb 1 |
| Externally published | Yes |
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Keywords
- ISM: atoms
- ISM: clouds
- ISM: individual (Orion Kleinmann-Low)
ASJC Scopus subject areas
- Space and Planetary Science
Cite this
Observation of the C I 3P2-3P1 line toward the Orion Kleinmann-Low region. / Yamamoto, Satoshi; Maezawa, Hiroyuki; Ikeda, Masafumi; Ito, Tetsuya; Oka, Tomoharu; Saito, Gaku; Iwata, Mitsuhiro; Kamegai, Kazuhisa; Sakai, Takeshi; Sekimoto, Yutaro; Tatematsu, Ken'ichi; Noguchi, Takashi; Shi, Sheng Cai; Arikawa, Yuji; Aso, Yoshiyuki; Miyazawa, Keisuke; Saito, Shuji; Fujiwara, Hideo; Ohishi, Masatoshi; Ozeki, Hiroyuki; Inatani, Junji.
In: Astrophysical Journal, Vol. 547, No. 2 PART 2, 01.02.2001.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Observation of the C I 3P2-3P1 line toward the Orion Kleinmann-Low region
AU - Yamamoto, Satoshi
AU - Maezawa, Hiroyuki
AU - Ikeda, Masafumi
AU - Ito, Tetsuya
AU - Oka, Tomoharu
AU - Saito, Gaku
AU - Iwata, Mitsuhiro
AU - Kamegai, Kazuhisa
AU - Sakai, Takeshi
AU - Sekimoto, Yutaro
AU - Tatematsu, Ken'ichi
AU - Noguchi, Takashi
AU - Shi, Sheng Cai
AU - Arikawa, Yuji
AU - Aso, Yoshiyuki
AU - Miyazawa, Keisuke
AU - Saito, Shuji
AU - Fujiwara, Hideo
AU - Ohishi, Masatoshi
AU - Ozeki, Hiroyuki
AU - Inatani, Junji
PY - 2001/2/1
Y1 - 2001/2/1
N2 - The 3P2-3P1 fine-structure line of the neutral carbon atom (809 GHz) has been observed toward the Orion Kleinmann-Low (KL) region with the Mount Fuji submillimeter-wave telescope. The 6′ × 6′ area centered at Orion KL has been mapped with a grid spacing of 1′.5. The intensity distribution of the 3P2-3P1 line is found to be similar to that of the 3P1-3P0 line; these lines are rather weak toward Orion KL, while they are both bright at Orion KL's northern and southern positions. The excitation temperature determined from the intensity ratio between the 3P2-3P1 and 3P1-3P0 lines ranges from 40 to 110 K. The excitation temperature is not enhanced toward Orion KL, whereas it tends to be high in the vicinity of θ1 Orionis C. These results indicate that the C I emission arises from a photodissociation surface illuminated by strong UV radiation from θ1 Ori C. The relative reduction in the C I intensities toward Orion KL is found to originate from a relatively low excitation temperature rather than from the depletion of the C I column density. The origin of the low-excitation temperature of C I toward Orion KL is discussed in terms of a radiative transfer effect.
AB - The 3P2-3P1 fine-structure line of the neutral carbon atom (809 GHz) has been observed toward the Orion Kleinmann-Low (KL) region with the Mount Fuji submillimeter-wave telescope. The 6′ × 6′ area centered at Orion KL has been mapped with a grid spacing of 1′.5. The intensity distribution of the 3P2-3P1 line is found to be similar to that of the 3P1-3P0 line; these lines are rather weak toward Orion KL, while they are both bright at Orion KL's northern and southern positions. The excitation temperature determined from the intensity ratio between the 3P2-3P1 and 3P1-3P0 lines ranges from 40 to 110 K. The excitation temperature is not enhanced toward Orion KL, whereas it tends to be high in the vicinity of θ1 Orionis C. These results indicate that the C I emission arises from a photodissociation surface illuminated by strong UV radiation from θ1 Ori C. The relative reduction in the C I intensities toward Orion KL is found to originate from a relatively low excitation temperature rather than from the depletion of the C I column density. The origin of the low-excitation temperature of C I toward Orion KL is discussed in terms of a radiative transfer effect.
KW - ISM: atoms
KW - ISM: clouds
KW - ISM: individual (Orion Kleinmann-Low)
UR - http://www.scopus.com/inward/record.url?scp=18044400022&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=18044400022&partnerID=8YFLogxK
U2 - 10.1086/318901
DO - 10.1086/318901
M3 - Article
AN - SCOPUS:18044400022
VL - 547
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 PART 2
ER -