Three New Supernova Remnant OH Masers Near the Galactic Center: Evidence for Large Scale Maser Emission from Supernova Remnants

Abstract

A survey of the inner 8${}^{\circ }\times 1^{\circ }$ of the Galactic plane toward the Galactic center has been carried out at the 1720 MHz transition of OH molecule using the VLA in its D configuration with a resolution of $\approx 70^{\prime \prime }\times 45^{\prime \prime }$. The detection of compact 1720 MHz OH masers associated with three supernova remnants G357.7+0.3, G1.13--0.1 (Sgr D) and G1.4--0.1 as well as new extended maser line emission from G357.7+0.3 and G357.7--0.1 (the Tornado Nebula) were then followed up by A-array observations with spectral and spatial resolutions of 0.3 \kms and $\approx 3^{\prime \prime }\times 2^{\prime \prime }$, respectively. The 1720 MHz OH maser line emission is considered to be a powerful shock diagnostic and is collisionally pumped by H${}_2$ molecules at the site where C-type supernova shocks drive into adjacent molecular clouds. The new observations show clear evidence of extended features coincident with compact and bright masers, the best example of which is a coherent feature over a scale of about 20 pc surrounding the shell of the SNR G357.7+0.3. We argue that this remarkable feature is an OH maser and is physically associated with the remnant. This implies that the ambient molecular cloud is uniform in its density and temperature with restricted range of pumping conditions and survives the passage of a large-scale shock front.

22 pages, 5 figures, one table, Astrophysical Journal (in press)

References in corpus (6)

• OH 1720 MHz Masers in Supernova Remnants --- C-Shock Indicators
• Shock-Excited Maser Emission from Supernova Remnants: G32.8-0.1, G337.8-0.1, G346.6-0.2, and the HB3/W3 Complex
• OH(1720 MHz) Masers As Signposts of Molecular Shocks
• Excitation and Disruption of a Giant Molecular Cloud by the Supernova Remnant 3C391
• High-resolution Observations of OH(1720 MHz) Masers Toward the Galactic Center
• Detection of Far-Infrared Water Vapor, Hydroxyl, and Carbon Monoxide Emissions from the Supernova Remnant 3C 391

Cited by in corpus (47)

• Supernova remnants: the X-ray perspective
• The 1st Fermi Lat Supernova Remnant Catalog
• Star Formation in the Central 400 pc of the Milky Way: Evidence for a Population of Massive YSOs
• A $\lambda$20cm Survey of the Galactic Center Region I: Detection of Numerous Linear Filaments
• Cavity of Molecular Gas Associated with Supernova Remnant 3C 397
• Enhanced abundances in three large-diameter mixed-morphology supernova remnants
• OH Zeeman Magnetic Field Detections Toward Five Supernova Remnants Using the VLA
• The AGASA/SUGAR Anisotropies and TeV Gamma Rays from the Galactic Center: A Possible Signature of Extremely High-energy Neutrons
• A Survey of Hydroxyl Toward Supernova Remnants: Evidence for Extended 1720 MHz Maser Emission
• A Systematic Survey for Broadened CO Emission Toward Galactic Supernova Remnants
• Discovery of New Interacting Supernova Remnants in the Inner Galaxy
• Widespread Methanol Emission from the Galactic Center
• GBT Observations of IC 443: the Nature of OH(1720 MHz) Masers and OH Absorption
• Correlation of Supernova Remnant Masers and Gamma-Ray Sources
• A Kinship between the EGRET SNR's and Sgr A East
• The Origin of the Galactic Center Nonthermal Radio Filaments: Young Stellar Clusters
• Detection of Class I Methanol (CH3OH) Maser Candidates in Supernova Remnants
• The OH (1720 MHz) Supernova Remnant Masers in W44: MERLIN and VLBA Polarization Observations
• Locating the intense interstellar scattering towards the inner Galaxy
• The X-ray Ridge Surrounding Sgr A* at the Galactic Center
• Shocked molecular gas towards the SNR G359.1-0.5 and the Snake
• The Sgr B2 X-ray Echo of the Galactic Center Supernova Explosion that Produced Sgr A East
• A Complete Catalogue of Dusty Supernova Remnants
• The Sizes of OH (1720 MHz) Supernova Remnant Masers: MERLIN and VLBA Observations of IC443
• Radio continuum emission from the central stars of M20 and the detection of a new supernova remnant near M20
• Thermal OH (1667/65 MHz) Absorption and Nonthermal OH (1720 MHz) Emission Towards the W28 Supernova Remnant
• G28.17+0.05: An unusual giant HI cloud in the inner Galaxy
• Shocked molecular hydrogen towards the Tornado nebula
• Evidence of a Hadronic Origin for the TeV Source J1834-087
• High Velocity Compact Clouds in the Sagittarius C Region
• Wind-Swept Clouds and Possible Triggered Star-Formation associated with the Supernova Remnant G357.7+0.3
• Discovery of Broad Molecular lines and of Shocked Molecular Hydrogen from the Supernova Remnant G357.7+0.3: HHSMT, APEX, Spitzer and SOFIA Observations
• A Clustering Analysis of the Morphology of the 130 GeV Gamma-Ray Feature
• A search for OH 6 GHz maser emission towards supernova remnants
• An OH(1720 MHz) Maser and a Nonthermal Radio Source in Sgr B2(M): A SNR--Molecular Cloud Interaction Site?
• MAGMO: Polarimetry of 1720-MHz OH Masers towards Southern Star Forming Regions
• Electron Positron Annihilation Radiation from SgrA East at the Galactic Center
• 327-MHz GMRT observations of one candidate and three Galactic Supernova Remnants
• Imaging of Four Galactic Supernovae Remnants in the Mid-Infrared, and their Interaction with the Interstellar Medium
• The Eye of the Tornado - an isolated, high mass young stellar object near the Galactic centre
• Shocked Molecular Hydrogen and Broad CO lines from the Interacting Supernova Remnant HB 3
• Suzaku Discovery of Twin Thermal Plasma from the Tornado Nebula
• The Interaction of Supernova Remnant G357.7+0.3 with the Interstellar Medium
• OH Masers and Supernova Remnants
• Millimeter-wave Molecular Line Observations of the Tornado Nebula
• Extended OH(1720 MHz) Maser Emission from Supernova Remnants
• A 95 GHz Methanol Emission Survey Toward Eight Small Supernova Remnants