English
Related papers

Related papers: Ground-state OH observations towards NGC 6334

200 papers

We present high spatial resolution observations of ground-state OH masers achieved with the Australia Telescope Compact Array (ATCA). These observations targeted 253 pointing centres containing OH maser candidates at all four ground-state…

We used the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to perform phase-referenced VLBI observations of the three most powerful maser transitions associated with the high-mass star-forming region G28.87+0.07: the…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. J. Li , L. Moscadelli , R. Cesaroni , R. S. Furuya , Y. Xu , T. Usuda , K. M. Menten , M. Pestalozzi , D. Elia , E. Schisano

MERLIN measurements of 1.6-GHz OH masers associated with Orion-BN/KL are presented, and the data are compared with data on other masers, molecular lines, compact radio continuum sources and infrared sources in the region. OH masers are…

Astrophysics · Physics 2009-11-11 R. J. Cohen , N. Gasipron , J. Meaburn , M. F. Graham

High-resolution VLA observations of 1720 MHz OH maser emission from Sgr A East and the circumnuclear disk with spatial and spectral resolutions of $\approx$ 2\dasec5 $\times$ 1\dasec3 and 0.27 \kms are reported. This follow-up observational…

Astrophysics · Physics 2009-10-30 F. Yusef-Zadeh , D. A. Roberts , W. M. Goss , D. A. Frail , A. J. Green

Using the Very Long Baseline Array (VLBA) we performed a high resolution OH maser survey in Galactic star-forming regions (SFRs). We observed all the ground state spectral lines: the main lines at 1665 and 1667 MHz and the satellite lines…

Solar and Stellar Astrophysics · Physics 2016-03-28 A. E. Ruiz-Velasco , D. Felli , V. Migenes , B. K. Wiggins

Context: Ground-state OH maser emission from late-type stars is usually polarized and remains a powerful probe of the magnetic field structure in the outer regions of circumstellar envelopes if observed with high angular and spectral…

Astrophysics of Galaxies · Physics 2011-10-11 Paweł Wolak , Marian Szymczak , Eric Gérard

We present the results of deep radio observations of 7 nearby large galaxies observed using the upgraded Giant Metrewave Radio Telescope (uGMRT) 0.3-0.5 GHz receivers with an angular resolution of $\sim$10 arcsec. The achieved sensitivities…

Astrophysics of Galaxies · Physics 2024-11-05 Souvik Manna , Subhashis Roy , Tapas Baug

We investigate the nuclear environment of galaxies with observed 22 GHz water megamaser in their subparsec edge-on accretion disks, using 33 GHz (9mm) radio continuum data from VLA, with a resolution of ~ 0.2-0.5 arcsecs, and relate the…

Despite much searching, redshifted decimetre and millimetre-band absorption by molecular gas remains very rare, limited to just six systems at z > 0.05. Detection of these transitions can yield precise diagnostics of the conditions of the…

Astrophysics of Galaxies · Physics 2021-10-04 S. J. Curran

Broad hydroxyl (OH) absorption-lines in the 1667 MHz and 1665 MHz transition towards the central region of NGC 3079 have been observed at high resolution with the European VLBI Network (EVN). Velocity fields of two OH absorption components…

Astrophysics · Physics 2009-11-10 Y. Hagiwara , H. -R. Kloeckner , W. Baan

The first complete far-infrared spectrum (43-197um) of the Seyfert 2 galaxy NGC 1068 as observed with the LWS onboard ISO is reported. In addition to the expected ionic fine structure emission lines, the OH rotational lines at 79, 119 and…

We present phase-referenced VLBI results on the radio continuum and the OH 18 cm megamaser emission from the Ultra-Luminous Infrared Galaxy, IRAS 17208--0014. The observations were carried out at 1599 MHz using the Very Long Baseline Array,…

Astrophysics · Physics 2008-11-26 E. Momjian , J. D. Romney , C. L. Carilli , T. H. Troland

We demonstrate that the observed characteristics of the 5 cm OH masers in star-forming regions can be explained with the same model and the same parameters as the 18 cm and the 6 cm OH masers. In our already published study of the 18 cm and…

Astrophysics · Physics 2009-10-31 K. G. Pavlakis , N. D. Kylafis

The population inversion which leads to the 1612 MHz OH maser emission has long been thought to be radiatively pumped. Since OH rotational lines involved in this pumping scheme lie in the far-infrared they became observable only after the…

Astrophysics · Physics 2007-05-23 R. Szczerba , J. H. He , P. S. Chen

We report the first sub-arcsecond VLA imaging of 6 GHz continuum, methanol maser, and excited-state hydroxyl maser emission toward the massive protostellar cluster NGC6334I following the recent 2015 outburst in (sub)millimeter continuum…

As a product of the maser monitoring program with the 26m telescope of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), we present an unprecedented, contemporaneous flaring event of 10 maser transitions in hydroxyl, methanol, and…

The intensities of the three widely observed radio-wavelength hyperfine structure (HFS) lines between the {\Lambda}-doublet components of the rotational ground state of CH are inconsistent with LTE and indicate ubiquitous population…

Astrophysics of Galaxies · Physics 2021-06-23 Arshia M. Jacob , Karl M. Menten , Helmut Wiesemeyer , Gisela N. Ortiz-León

The bright radio structure of the LINER elliptical galaxy NGC1052 is dominated by bi-symmetric jets on parsec scales. Features move outward on both sides of the core at v_{app}~0.26c. We have established the occurrence of free-free…

We report deep Green Bank Telescope spectroscopy in the redshifted HI 21cm and OH 18cm lines from the $z = 0.765$ absorption system towards PMN J0134-0931. A comparison between the "satellite" OH 18cm line redshifts, or between the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 N. Kanekar , G. I. Langston , J. T. Stocke , C. L. Carilli , K. L. Menten

Aims. We investigate the spatial distribution of a collection of absorbing gas clouds, some associated with the dense, massive star-forming core NGC6334 I, and others with diffuse foreground clouds. For the former category, we aim to study…

Astrophysics of Galaxies · Physics 2016-09-14 M. H. D. van der Wiel , D. A. Naylor , G. Makiwa , M. Satta , A. Abergel