Supernova Shocks in Molecular Clouds: Velocity Distribution of Molecular Hydrogen

Abstract

Supernovae from core-collapse of massive stars drive shocks into the molecular clouds from which the stars formed. Such shocks affect future star formation from the molecular clouds, and the fast-moving, dense gas with compressed magnetic fields is associated with enhanced cosmic rays. This paper presents new theoretical modeling, using the Paris-Durham shock model, and new observations, using the Stratospheric Observatory for Infrared Astronomy (SOFIA), of the H${}_2$ S(5) pure rotational line from molecular shocks in the supernova remnant IC443. We generate MHD models for non-steady-state shocks driven by the pressure of the IC443 blast wave into gas of densities $10^3$ to $10^5$ cm${}^{-3}$. We present the first detailed derivation of the shape of the velocity profile for emission from H${}_2$ lines behind such shocks, taking into account the shock age, preshock density, and magnetic field. For preshock densities $10^3$-$10^5$ cm${}^{-3}$, the the predicted shifts of line centers, and the line widths, of the H${}_2$ lines range from 20-2, and 30-4 km/s, respectively. The a priori models are compared to the observed line profiles, showing that clumps C and G can be explained by shocks into gas with density 10${}^3$ to $2\times 10^4$ cm${}^{-3}$ and strong magnetic fields. For clump B2 (a fainter region near clump B), the H${}_2$ spectrum requires a J-type shock into moderate density (~100 cm${}^{-3}$) with the gas accelerated to 100 km/s from its pre-shock location. Clump B1 requires both a magnetic-dominated C-type shock (like for clumps C and G) and a J-type shock (like for clump B1) to explain the highest observed velocities. The J-type shocks that produce high-velocity molecules may be locations where the magnetic field is nearly parallel to the shock velocity, which makes it impossible for a C-type shock (with ions and neutrals separated) to form.

arXiv commentaccepted by ApJ (9/4/2019)

References in corpus (28)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• Early Science with SOFIA, the Stratospheric Observatory for Infrared Astronomy
• Supernova Remnants in Molecular Clouds
• A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy
• TEXES: A Sensitive High-Resolution Grating Spectrograph for the Mid-Infrared
• Observation of Supernova Remnant IC443 with the Fermi Large Area Telescope
• Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope
• A Bow Shock Nebula Around a Compact X-Ray Source in the Supernova Remnant IC443
• Observation of Extended VHE Emission from the Supernova Remnant IC 443 with VERITAS
• Direct Evidence for Hadronic Cosmic-Ray Acceleration in the Supernova Renmant IC 443
• Low velocity shocks: signatures of turbulent dissipation in diffuse irradiated gas
• HAWC+/SOFIA Multiwavelength Polarimetric Observations of OMC-1
• Investigating the Cosmic-Ray Ionization Rate Near the Supernova Remnant IC 443 Through H3+ Observations
• Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis
• OH Zeeman Magnetic Field Detections Toward Five Supernova Remnants Using the VLA
• XMM-Newton observations of the supernova remnant IC 443: II. evidence of stellar ejecta in the inner regions
• Models of irradiated molecular shocks
• The X-ray Structure of the Pulsar Bow Shock G189.22+2.90 in the Supernova Remnant IC 443
• Core collapse supernovae as Cosmic Ray sources
• MAGIC J0616+225 as delayed TeV emission of cosmic-rays diffusing from SNR IC 443
• High Spatial Resolution X-Ray Spectroscopy of the IC443 Pulsar Wind Nebula and Environs
• OH (1720 MHz) Masers: A Multiwavelength Study of the Interaction between the W51C Supernova Remnant and the W51B Star Forming Region
• Temporal evolution of magnetic molecular shocks II. Analytics of the steady state and semi-analytical construction of intermediate ages
• Identification of Ambient Molecular Clouds Associated with Galactic Supernova Remnant IC443
• Dust charge distribution in the interstellar medium
• AKARI Near-infrared Spectral Observations of Shocked H2 Gas of the Supernova Remnant IC 443
• H${}_2$ emission from non-stationary magnetized bow shocks

Cited by in corpus (11)

• Shock excitation of H${}_2$ in the James Webb Space Telescope era
• The Obscured Nucleus and Shocked Environment of VV 114E Revealed by JWST/MIRI Spectroscopy
• Negative and Positive Feedback from a Supernova Remnant with SHREC: A detailed Study of the Shocked Gas in IC443
• Self-generated ultraviolet radiation in molecular shock waves II. CH+ and the interpretation of emission from shock ensembles
• Interstellar anatomy of the TeV gamma-ray peak in the IC443 supernova remnant
• Submillimeter observations of molecular gas interacting with the supernova remnant W28
• Multiple gas phases in supernova remnant IC 443: mapping shocked H${}_2$ with VLT/KMOS
• Shocks and Molecules in Diffuse Interstellar Cloud Pairs
• Large-field CO (J=1-0) observations toward SNR G150.3+4.5
• Supernova Shocks in Molecular Clouds: Shocks Driven into Dense Cores in IC 443 and 3C 391
• A Spectroscopic Study of Supernova Remnants with the Infrared Space Observatory