A study of the ground-state hydroxyl maser emission associated with 11 regions of star formation

Gaume, R. A.; Mutel, R. L.

doi:10.1086/191223

Cited by 142 publications

(185 citation statements)

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“…G31.41+0.31: This is a well-studied hot core located at 7.9 kpc (Cesaroni et al 1994(Cesaroni et al , 1998, with evidence of a rotating massive molecular toroid, suggested by OH maser emission and confirmed using CH3CN emission (Gaume & Mutel 1987;Beltrán et al 2004Beltrán et al , 2005Cesaroni et al 2011). It has been mapped in several different molecules including SiO, HCO + and NH3, as well as several complex molecules like CH3CN, C2H5CN and CH2(OH)CHO (Cesaroni et al 1994;Maxia et al 2001;Beltrán et al 2005).…”

Section: The Sample Of Hot Coresmentioning

confidence: 78%

A high-resolution study of complex organic molecules in hot cores

Calcutt

Viti

Codella

et al. 2014

Monthly Notices of the Royal Astronomical Society

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We present the results of a line identification analysis using data from the IRAM Plateau de Bure Inferferometer, focusing on six massive star-forming hot cores: G31.41+0.31, G29.96-0.02, G19.61-0.23, G10.62-0.38, G24.78+0.08A1 and G24.78+0.08A2. We identify several transitions of vibrationally excited methyl formate (HCOOCH 3 ) for the first time in these objects as well as transitions of other complex molecules, including ethyl cyanide (C 2 H 5 CN), and isocyanic acid (HNCO). We also postulate a detection of one transition of glycolaldehyde (CH 2 (OH)CHO) in two new hot cores. We find G29.96-0.02, G19.61-0.23, G24.78+0.08A1 and G24.78+0.08A2 to be chemically very similar. G31.41+0.31, however, is chemically different: it manifests a larger chemical inventory and has significantly larger column densities. We suggest that it may represent a different evolutionary stage to the other hot cores in the sample, or it may surround a star with a higher mass. We derive column densities for methyl formate in G31.41+0.31, using the rotation diagram method, of 4×10 17 cm −2 and a T rot of ∼170 K. For G29.96-0.02, G24.78+0.08A1 and G24.78+0.08A2, glycolaldehyde, methyl formate and methyl cyanide all seem to trace the same material and peak at roughly the same position towards the dust emission peak. For G31.41+0.31, however, glycolaldehyde shows a different distribution to methyl formate and methyl cyanide and seems to trace the densest, most compact inner part of hot cores.

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Section: The Sample Of Hot Coresmentioning

confidence: 78%

A high-resolution study of complex organic molecules in hot cores

Calcutt

Viti

Codella

et al. 2014

Monthly Notices of the Royal Astronomical Society

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“…G049.469À0.370.-In 18 cm VLA observations, Gaume & Mutel (1987) also find a Zeeman pair with a positive magnetic field. For more information, see the notes for the next source.…”

Section: Satellite-line Field Splittingmentioning

confidence: 91%

“…-Gaume & Mutel (1987) find about half a dozen Zeeman pairs in the W51 complex around regions e1 and e2, all indicating a positive magnetic field. In 5 cm VLBI observations, Desmurs & Baudry (1998) G081.871+0.781.-Preliminary (as yet unpublished) VLBA observations indicate a reversal of the line-of-sight magnetic field direction across the source.…”

Section: No 1 2003mentioning

confidence: 94%

Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field

Fish

Reid

Argon

et al. 2003

ApJ

115

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We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive starforming regions with 18 cm ( 2 Å 3=2 ; J ¼ 3=2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50 massive star-forming regions. The magnetic field deduced from the Zeeman splitting has allowed us to assign an overall line-of-sight magnetic field direction to many of the massive starforming regions. Combining these data with other data sets obtained from OH Zeeman splitting, we have looked for correlations of magnetic field directions between star-forming regions scattered throughout the Galaxy. Our data do not support a uniform, Galactic-scale field direction, nor do we find any strong evidence of magnetic field correlations within spiral arms. However, our data suggest that in the solar neighborhood the magnetic field outside the solar circle is oriented clockwise as viewed from the north Galactic pole, while inside the solar circle it is oriented counterclockwise. This pattern, including the magnetic field reversal near the Sun, is in agreement with results obtained from pulsar rotation measures.

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“…NGC 6334I is a prototypical hot molecular core right at the head of a cometary ultracompact Hii (UCHii) region (de Pree et al 1995;Kraemer & Jackson 1995). It exhibits rich spectral line emission (McCutcheon et al 2000;Thorwirth et al 2003;Schilke et al 2006), a bipolar outflow (Bachiller & Cernicharo 1990; Leurini et al 2006) and H 2 O, OH, CH 3 OH class ii and NH 3 (3, 3)/(6, 6)/(8, 6)/(11, 9) maser emission (Moran & Rodríguez 1980;Forster & Caswell 1989;Gaume & Mutel 1987;Brooks & Whiteoak 2001;Norris et al 1993;Caswell 1997;Walsh et al 1998;Beuther et al 2007b;Walsh et al 2007). In contrast to that, up to very recently NGC 6334I(N) was Article published by EDP Sciences considered a typical cold core since no mid-infrared and only faint near-infrared emission was detected (Gezari 1982;Tapia et al 1996;Persi et al 2005).…”

Section: Introductionmentioning

confidence: 99%

ATCA 3 mm observations of NGC 6334I and I(N): dense cores, outflows, and an UCH II region

Beuther¹,

Walsh²,

Thorwirth

et al. 2008

A&A

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Aims. We investigate the dense gas, the outflows, and the continuum emission from the massive twin cores NGC 6334I and I(N) at high spatial resolution. Methods. We imaged the region with the Australia Telescope Compact Array (ATCA) at 3.4 mm wavelength in continuum, as well as CH 3 CN(5 K −4 K ) and HCN(1−0) spectral line emission. Results. While the continuum emission in NGC 6334I mainly traces the UCHii region, toward NGC 6334I(N) we detect continuum emission from four of the previously identified dust continuum condensations that are of protostellar or pre-stellar nature. The CH 3 CN(5 K −4 K ) lines are detected in all K-components up to energies of 128 K aboveground toward two protostellar condensations in both regions. We find line width increasing with increasing K for all sources, which indicates a higher degree of internal motions of the hotter gas probed by these high K-transitions. Toward the main mm and CH 3 CN source in NGC 6334I, we identify a velocity gradient approximately perpendicular to the large-scale molecular outflow. This may be interpreted as a signature of an accretion disk, although other scenarios, e.g., an unresolved double source, could produce a similar signature. No comparable signature is found toward any of the other sources. HCN does not trace the dense gas well in this region but it is dominated by the molecular outflows. While the outflow in NGC 6334I exhibits a normal Hubble-law like velocity structure, the data are consistent with a precessing outflow close to the plane of the sky for NGC 6334I(N). Furthermore, we observe a wide (∼15.4 km s −1 ) HCN absorption line, much broader than the previously observed CH 3 OH and NH 3 absorption lines. Several explanations for the difference are discussed. The fits-files of the 3.4 mm continuum images and of the HCN(1−0) and CH 3 CN(5 K −4 K ) data-cubes are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via

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A study of the ground-state hydroxyl maser emission associated with 11 regions of star formation

Cited by 142 publications

References 0 publications

A high-resolution study of complex organic molecules in hot cores

A high-resolution study of complex organic molecules in hot cores

Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field

ATCA 3 mm observations of NGC 6334I and I(N): dense cores, outflows, and an UCH II region

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