OH (1720 MHz) Maser Search Toward the Large Magellanic Cloud

Abstract

We have carried out a sensitive search for OH (1720 MHz) masers in the Large Magellanic Cloud (LMC) toward five regions using the Australia Telescope Compact Array (ATCA). Our source list includes the 30 Doradus region, and four supernova remnants (SNRs): N44, N49, N120, and N132D. These data have a typical resolution of ~8 arcsec and rms noise levels of 5-10 mJy/beam. We have detected OH (1720 MHz) masers in the NE part of 30 Doradus and toward the SNR N49. The OH (1720 MHz) maser emission in 30 Doradus is coincident with a cluster of young stars known as ``Knot 1'', and is almost certainly of the star formation variety. Our spectral resolution (0.68 km/s) is insufficient to detect the Zeeman effect from the strongest (320 mJy/beam) of the 30 Doradus OH (1720 MHz) masers, leading to an upper limit to the field strength of 6 mG. The weak OH (1720 MHz) maser emission (35 mJy/beam) detected toward the LMC SNR N49 is located just west of a previously identified CO cloud, and are indicative of an interaction between the SNR and the molecular cloud. Although the statistics are low, the detection rate seems consistent with that seen for Galactic star forming regions and SNR type OH (1720 MHz) masers -- both of which are low.

arXiv comment20 pages, 7 figures, Accepted to AJ

References in corpus (17)

• Polarization Observations of 1720 MHz OH Masers toward the Three Supernova Remnants W28, W44, and IC443
• 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
• Enhanced OH in C-type shock waves in molecular clouds
• OH(1720 MHz) Masers As Signposts of Molecular Shocks
• Supernova Remnants in the Magellanic Clouds III: An X-ray Atlas of LMC Supernova Remnants
• Excitation and Disruption of a Giant Molecular Cloud by the Supernova Remnant 3C391
• OH Zeeman Magnetic Field Detections Toward Five Supernova Remnants Using the VLA
• Supernova Remnants Associated with Molecular Clouds in the Large Magellanic Cloud
• High-resolution Observations of OH(1720 MHz) Masers Toward the Galactic Center
• A dozen colliding wind X-ray binaries in the star cluster R136 in the 30Doradus region
• X-Ray Emission from Multi-Phase Shock in the Large Magellanic Cloud Supernova Remnant N49
• The Sizes of 1720 MHz OH Masers: VLBA and MERLIN Observations of the Supernova Remnants W44 and W28
• ASCA Observations of the Thermal Composite Supernova Remnant 3C 391
• Observations of ground-state OH in the Large Magellanic Cloud
• The Sizes of OH (1720 MHz) Supernova Remnant Masers: MERLIN and VLBA Observations of IC443
• The Size of the Extragalactic Source J1801-231 and the Association of Pulsar PSR B1758-23 with the Supernova Remnant W28

Cited by in corpus (11)

• A Chandra/ACIS Study of 30 Doradus II. X-ray Point Sources in the Massive Star Cluster R136 and Beyond
• ALMA Resolves 30 Doradus: Sub-parsec Molecular Cloud Structure Near the Closest Super-Star Cluster
• A Survey of Hydroxyl Toward Supernova Remnants: Evidence for Extended 1720 MHz Maser Emission
• A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. I. The Large Magellanic Cloud
• Revisiting the distance, environment and supernova properties of SNR G57.2+0.8 that hosts SGR 1935+2154
• Massive Young Stellar Objects in the Large Magellanic Cloud: water masers and ESO-VLT 3-4 micron spectroscopy
• Chandra detection of ejecta in the small-diameter supernova remnant G349.7+0.2
• Structural and Dynamical Analysis of 0.1pc Cores and Filaments in the 30~Doradus-10 Giant Molecular Cloud
• A search for OH 6 GHz maser emission towards supernova remnants
• The application of MultiView Methods for High Precision Astrometric Space VLBI at Low Frequencies
• A Survey for Ground-State OH Masers Toward a Sample of Herbig-Haro Objects