TY - JOUR
T1 - DISCOVERY of BROAD MOLECULAR LINES and of SHOCKED MOLECULAR HYDROGEN from the SUPERNOVA REMNANT G357.7+0.3
T2 - HHSMT, APEX, SPITZER, and SOFIA OBSERVATIONS
AU - Rho, J.
AU - Hewitt, J. W.
AU - Bieging, J.
AU - Reach, W. T.
AU - Andersen, M.
AU - Güsten, R.
N1 - Funding Information:
The Arizona Radio Observatory is part of the Steward Observatory at the University of Arizona and receives partial support from the National Science Foundation. Based (in part) on observations made with the NASA/DLR Stratospheric Observatory for Infrared Astronomy. SOFIA Science Mission Operations are conducted jointly by the Universities Space Research Association, Inc., under NASA contract NAS2-97001, and the Deutsches SOFIA Institut under DLR contract 50 OK 0901.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - We report a discovery of shocked gas from the supernova remnant (SNR) G357.7+0.3. Our millimeter and submillimeter observations reveal broad molecular lines of CO(2-1), CO(3-2), CO(4-3), 13CO (2-1), and 13CO (3-2), HCO+, and HCN using the Heinrich Hertz Submillimeter Telescope, the Arizona 12 m Telescope, APEX, and the MOPRA Telescope. The widths of the broad lines are 15-30 km s-1, and the detection of such broad lines is unambiguous, dynamic evidence showing that the SNR G357.7+0.3 is interacting with molecular clouds. The broad lines appear in extended regions (>4.′5 × 5′). We also present the detection of shocked H2 emission in the mid-infrared but lacking ionic lines using Spitzer/IRS observations to map a few-arcminute area. The H2 excitation diagram shows a best fit with a two-temperature local thermal equilibrium model with the temperatures of ∼200 and 660 K. We observed [C ii] at 158 μm and high-J CO(11-10) with the German Receiver for Astronomy at Terahertz Frequencies (GREAT) on the Stratospheric Observatory for Infrared Astronomy. The GREAT spectrum of [C ii], a 3σ detection, shows a broad line profile with a width of 15.7 km-1 that is similar to those of broad CO molecular lines. The line width of [C ii] implies that ionic lines can come from a low-velocity C-shock. Comparison of H2 emission with shock models shows that a combination of two C-shock models is favored over a combination of C- and J-shocks or a single shock. We estimate the CO density, column density, and temperature using a RADEX model. The best-fit model with n(H2) = 1.7 ×104 cm-3, N(CO) = 5.6 ×1016 cm-2, and T = 75 K can reproduce the observed millimeter CO brightnesses.
AB - We report a discovery of shocked gas from the supernova remnant (SNR) G357.7+0.3. Our millimeter and submillimeter observations reveal broad molecular lines of CO(2-1), CO(3-2), CO(4-3), 13CO (2-1), and 13CO (3-2), HCO+, and HCN using the Heinrich Hertz Submillimeter Telescope, the Arizona 12 m Telescope, APEX, and the MOPRA Telescope. The widths of the broad lines are 15-30 km s-1, and the detection of such broad lines is unambiguous, dynamic evidence showing that the SNR G357.7+0.3 is interacting with molecular clouds. The broad lines appear in extended regions (>4.′5 × 5′). We also present the detection of shocked H2 emission in the mid-infrared but lacking ionic lines using Spitzer/IRS observations to map a few-arcminute area. The H2 excitation diagram shows a best fit with a two-temperature local thermal equilibrium model with the temperatures of ∼200 and 660 K. We observed [C ii] at 158 μm and high-J CO(11-10) with the German Receiver for Astronomy at Terahertz Frequencies (GREAT) on the Stratospheric Observatory for Infrared Astronomy. The GREAT spectrum of [C ii], a 3σ detection, shows a broad line profile with a width of 15.7 km-1 that is similar to those of broad CO molecular lines. The line width of [C ii] implies that ionic lines can come from a low-velocity C-shock. Comparison of H2 emission with shock models shows that a combination of two C-shock models is favored over a combination of C- and J-shocks or a single shock. We estimate the CO density, column density, and temperature using a RADEX model. The best-fit model with n(H2) = 1.7 ×104 cm-3, N(CO) = 5.6 ×1016 cm-2, and T = 75 K can reproduce the observed millimeter CO brightnesses.
KW - ISM: individual objects (G357.7+0.3)
KW - ISM: supernova remnants
KW - infrared: ISM
KW - radio lines: ISM
UR - http://www.scopus.com/inward/record.url?scp=85010065664&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85010065664&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/834/1/12
DO - 10.3847/1538-4357/834/1/12
M3 - Article
AN - SCOPUS:85010065664
VL - 834
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 12
ER -