Interaction between the Northeastern Boundary of Sgr A East and Giant Molecular Clouds

Abstract

We have detected the v=1-0 S(1) (2.1218 um) and v=2-1 S(1) (2.2477 um) lines of H_2 in the Galactic centre, in a 90 x 27 arcsec region between the northeastern boundary of the non-thermal source, Sgr A East, and the giant molecular cloud (GMC) M-0.02-0.07. The detected H_2 v=1-0 S(1) emission has an intensity of 1.6 - 21 x 10^-18 W/m^2/arcsec^2 and is present over most of the region. Along with the high intensity, the broad line widths (FWHM = 40 - 70 km/s) and the 2-1 S(1) / 1-0 S(1) line ratios (0.3 - 0.5) can be best explained by a combination of C-type shocks and fluorescence. The detection of shocked H_2 is clear evidence that Sgr A East is driving material into the surrounding adjacent cool molecular gas. The H_2 emission lines have two velocity components at about +50 km/s and 0 km/s, which are also present in the NH_3(3,3) emission mapped by McGary, Coil, and Ho (2001, ApJ, 559, 326). This two-velocity structure can be explained if Sgr A East is driving C-type shocks into both the GMC M-0.02-0.07 and the northern ridge of McGary, Coil, and Ho (2001).

9 pages, 6 figures, accepted for publication in MNRAS, a few major changes in the conclusions

References in corpus (3)

• A Chandra Study of Sgr A East: A Supernova Remnant Regulating The Activity Of Our Galactic Center?
• High Spectral and Spatial Resolution Observations of Shocked Molecular Hydrogen at the Galactic Center
• NH3 in the Central 10 pc of the Galaxy I: General Morphology and Kinematic Connections Between the CND and GMCs

Cited by in corpus (7)

• Interstellar gas within $\sim 10$ pc of Sgr A${}^{\ast }$
• Milky Way Supermassive Black Hole: Dynamical Feeding from the Circumnuclear Environment
• Molecular Gas Feeding the Circumnuclear Disk of the Galactic Center
• Very Large Array Observations of Galactic Center OH 1720 MHz Masers in Sagittarius A East and in the Circumnuclear Disk
• Three-Dimensional Observations of H_2 Emission around Sgr A East - I. Structure in the Central 10 Parsecs of Our Galaxy
• A common origin for the circumnuclear disc and the nearby molecular clouds in the Galactic Centre
• High Resolution Observations of the Near-Infrared Emission from NGC 6822 Hubble V