TY - JOUR
T1 - Kinematics of shocked molecular gas adjacent to the supernova remnant W44
AU - Sashida, Tomoro
AU - Oka, Tomoharu
AU - Tanaka, Kunihiko
AU - Aono, Kazuya
AU - Matsumura, Shinji
AU - Nagai, Makoto
AU - Seta, Masumichi
PY - 2013/9/1
Y1 - 2013/9/1
N2 - We mapped molecular gas toward the supernova remnant W44 in the HCO + J = 1-0 line with the Nobeyama Radio Observatory 45 m telescope and in the CO J = 3-2 line with the Atacama Submillimeter Telescope Experiment 10 m telescope. High-velocity emission wings were detected in both lines over the area where the radio shell of W44 overlaps with the molecular cloud in the plane of the sky. We found that the average velocity distributions of the wing emission can be fit by a uniform expansion model. The best-fit expansion velocities are 12.2 ± 0.3 km s-1 and 13.2 ± 0.2 km s-1 in HCO+ and CO, respectively. The non-wing CO J = 3-2 component is also fit by the same model with an expansion velocity of 4.7 ± 0.1 km s-1. This component might be dominated by a post-shock higher-density region where the shock velocity had slowed down. The kinetic energy of the shocked molecular gas is estimated to be (3.5 ± 1.3) × 1049 erg. Adding this and the energy of the previously identified H I shell, we conclude that (1.2 ± 0.2) × 10 50 erg has been converted into gas kinetic energy from the initial baryonic energy of the W44 supernova. We also found ultra-high-velocity CO J = 3-2 wing emission with a velocity width of ∼100 km s-1 at (l, b) = (+34.°73, -0.°47). The origin of this extremely high velocity wing is a mystery.
AB - We mapped molecular gas toward the supernova remnant W44 in the HCO + J = 1-0 line with the Nobeyama Radio Observatory 45 m telescope and in the CO J = 3-2 line with the Atacama Submillimeter Telescope Experiment 10 m telescope. High-velocity emission wings were detected in both lines over the area where the radio shell of W44 overlaps with the molecular cloud in the plane of the sky. We found that the average velocity distributions of the wing emission can be fit by a uniform expansion model. The best-fit expansion velocities are 12.2 ± 0.3 km s-1 and 13.2 ± 0.2 km s-1 in HCO+ and CO, respectively. The non-wing CO J = 3-2 component is also fit by the same model with an expansion velocity of 4.7 ± 0.1 km s-1. This component might be dominated by a post-shock higher-density region where the shock velocity had slowed down. The kinetic energy of the shocked molecular gas is estimated to be (3.5 ± 1.3) × 1049 erg. Adding this and the energy of the previously identified H I shell, we conclude that (1.2 ± 0.2) × 10 50 erg has been converted into gas kinetic energy from the initial baryonic energy of the W44 supernova. We also found ultra-high-velocity CO J = 3-2 wing emission with a velocity width of ∼100 km s-1 at (l, b) = (+34.°73, -0.°47). The origin of this extremely high velocity wing is a mystery.
KW - ISM: clouds
KW - ISM: kinematics and dynamics
KW - ISM: molecules
KW - ISM: supernova remnants - radio lines: ISM
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U2 - 10.1088/0004-637X/774/1/10
DO - 10.1088/0004-637X/774/1/10
M3 - Article
AN - SCOPUS:84882973278
VL - 774
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 10
ER -