相关论文: Excited-state OH Masers and Supernova Remnants

Water is an important molecule in interstellar and circumstellar environments. Previous observations of mid-infrared rotational lines of OH suggest that these lines may be used to probe the photodissociation of water. In this work, cross…

Using the Haystack Observatory 37-m radio telescope we have undertaken a search for emission in the 2(0)-3(1)E rotational transition of methanol in its first torsionally excited state (v_t=1) at 44.9 GHz. We examined seven galactic sources…

We have observed the OH 1612-MHz maser emission towards the proto-planetary nebula candidate OH17.7-2.0 that underwent a very strong and unusual outburst in 2003. Phase-referencing data were obtained with the EVN in order to localize the…

We present $\sim1-4"$ resolution Very Large Array (VLA) observations of four CH$_3$OH $J_2-J_1$-$E$ 25~GHz transitions ($J$=3, 5, 8, 10) along with 1.3~cm continuum toward 20 regions of active massive star formation containing Extended…

We report the detection of shock-excited far-infrared emission of H2O, OH, and CO from the supernova remnant 3C 391, using the ISO Long-Wavelength Spectrometer. This is the first detection of thermal H2O and OH emission from a supernova…

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

We have observed six high-mass star-forming regions in the 2 Pi 3/2, J = 7/2 lines of OH using the GBT in order to investigate whether the magnetic field, and hence the density, measured in absorption differs from that implied by maser…

A sample of J-type carbon stars was searched for OH maser emission. The new detection of three OH lines towards two silicate carbon stars is reported. In V778 Cyg, previously known as the main-lines (1665 and 1667 MHz) maser source, the…

We present the first maps of 4765-MHz OH masers in two star-forming regions Cepheus A and W75N, made with Multi-Element Radio Linked Interferometer Network. In Cep A the emission has an arc-like structure of size 40 mas with a clear…

Context. HCN is a major constituent of the circumstellar envelopes of carbon-rich evolved stars, and rotational lines from within its vibrationally excited states probe parts of these regions closest to the stellar surface. A number of such…

Discovered in 1995 at the Caltech Submillimeter Observatory (CSO), the vibrationally-excited water maser line at 658 GHz (455 micron) is seen in oxygen-rich giant and supergiant stars. Because this maser can be so strong (up to thousands of…

Supernova remnants interacting with molecular clouds are potentially exciting systems in which to detect evidence of cosmic ray acceleration. Prominent gamma-ray emission is produced via the decay of neutral pions when cosmic rays encounter…

We review the class of galactic supernova remnants which show strong interactions with molecular clouds, revealed through shock-excited hydroxyl masers. These remnants are preferentially found among the known GeV and TeV detections of…

Recently, a comparison between the locations of 6.7-GHz methanol masers and dust continuum emission has renewed speculation that these masers can be associated with evolved stars. The implication of such a scenario would be profound,…

We present a model in which the 22 GHz H$_2$O masers observed in star-forming regions occur behind shocks propagating in dense regions (preshock density $n_0 \sim 10^6 - 10^8$ cm$^{-3}$). We focus on high-velocity ($v_s > 30$ km s$^{-1}$)…

The extended supernova remnant G 116.5+1.1 was observed in the optical emission lines of Halpha+[N II], [S II] and [O III]; deep long-slit spectra were also obtained. The morphology of the remnant's observed emission is mainly diffuse and…

The first images of 6.7-GHz methanol masers in the massive star-forming regions DR21(OH) and DR21(OH)N are presented. By measuring the shapes, radial velocities and polarization properties of these masers it is possible to map out the…

We present MERLIN observations of OH, water and methanol masers towards the young high mass stellar object IRAS 20126+4104. Emission from the 1665-MHz OH, 22-GHz H_2O and 6.7-GHz CH_3OH masers is detected and all originates very close to…

Results of monitoring the H$_2$O and OH masers in W44C, located near the cometary HII region G34.3+0.15, are reported. Observations in the water-vapor line at $\lambda = 1.35$ cm were carried out on the 22-meter radio telescope of the…

As part of the first far-IR line survey towards Orion KL, we present the detection of seven new rotationally excited OH Lambda-doublets (at 48, 65, 71, 79, 98 and 115 um). Observations were performed with the Long Wavelength Spectrometer…