scholarly journals Chemical differentiation in Sagittarius B2(N): first high resolution results

2013 ◽  
Vol 9 (S303) ◽  
pp. 205-207
Author(s):  
J. F. Corby ◽  
P. A. Jones ◽  
M. R. Cunningham ◽  
A. J. Remijan
Keyword(s):  
Organic Chemistry ◽  
High Resolution ◽  
Galactic Center ◽  
High Mass ◽  
Mass Star ◽  
Radio Interferometry ◽  
Broad Bandwidth ◽  
Star Forming ◽  
Spatially Resolved ◽  
Line Survey

AbstractSgr B2 is an active high mass star forming region in the Galactic center and the pre-eminent interstellar source of organic chemistry. Newly available broad bandwidth radio interferometry data enables a spatially resolved study of the chemical environments within the Sgr B2(N) core. We present selections from a 30 - 50 GHz spectral line survey conducted with the ATCA.

scholarly journals Molecular line survey of the high-mass star-forming region NGC 6334I withHerschel/HIFI and the Submillimeter Array

2012 ◽  
Vol 546 ◽  
pp. A87 ◽  
Author(s):  
A. Zernickel ◽  
P. Schilke ◽  
A. Schmiedeke ◽  
D. C. Lis ◽  
C. L. Brogan ◽  
...  
Keyword(s):  
High Mass ◽  
Mass Star ◽  
Molecular Line ◽  
Star Forming ◽  
Line Survey

scholarly journals High-mass star-forming cloud G0.38+0.04 in the Galactic center dust ridge contains H2CO and SiO masers

2015 ◽  
Vol 584 ◽  
pp. L7 ◽  
Author(s):  
Adam Ginsburg ◽  
Andrew Walsh ◽  
Christian Henkel ◽  
Paul A. Jones ◽  
Maria Cunningham ◽  
...  
Keyword(s):  
Galactic Center ◽  
High Mass ◽  
Mass Star ◽  
Star Forming

scholarly journals High resolution magnetic field measurements in high-mass star-forming regions using masers

2016 ◽  
Author(s):  
Gabriele Surcis ◽  
Wouter H.T. Vlemmings ◽  
Huib Jan van Langevelde ◽  
Busaba Hutawarakorn Kramer
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Field Measurements ◽  
High Mass ◽  
Mass Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Magnetic Field Measurements

scholarly journals ALMA CO observations of a giant molecular cloud in M 33: Evidence for high-mass star formation triggered by cloud–cloud collisions

2020 ◽  
Author(s):  
Hidetoshi Sano ◽  
Kisetsu Tsuge ◽  
Kazuki Tokuda ◽  
Kazuyuki Muraoka ◽  
Kengo Tachihara ◽  
...  
Keyword(s):  
Star Formation ◽  
Molecular Cloud ◽  
Molecular Clouds ◽  
Line Emission ◽  
High Mass ◽  
H Ii Regions ◽  
Mass Star ◽  
Star Forming ◽  
Spatially Resolved ◽  
Giant Molecular Cloud

Abstract We report the first evidence for high-mass star formation triggered by collisions of molecular clouds in M 33. Using the Atacama Large Millimeter/submillimeter Array, we spatially resolved filamentary structures of giant molecular cloud 37 in M 33 using 12CO(J = 2–1), 13CO(J = 2–1), and C18O(J = 2–1) line emission at a spatial resolution of ∼2 pc. There are two individual molecular clouds with a systematic velocity difference of ∼6 km s−1. Three continuum sources representing up to ∼10 high-mass stars with spectral types of B0V–O7.5V are embedded within the densest parts of molecular clouds bright in the C18O(J = 2–1) line emission. The two molecular clouds show a complementary spatial distribution with a spatial displacement of ∼6.2 pc, and show a V-shaped structure in the position–velocity diagram. These observational features traced by CO and its isotopes are consistent with those in high-mass star-forming regions created by cloud–cloud collisions in the Galactic and Magellanic Cloud H ii regions. Our new finding in M 33 indicates that cloud–cloud collision is a promising process for triggering high-mass star formation in the Local Group.

scholarly journals Multiline observations of S255IR with ALMA

2017 ◽  
Vol 13 (S332) ◽  
pp. 270-273 ◽  
Author(s):  
Igor Zinchenko ◽  
Sheng-Yuan Liu ◽  
Yu-Nung Su ◽  
Petr Zemlyanukha
Keyword(s):  
High Resolution ◽  
High Mass ◽  
Mass Star ◽  
Present Sample ◽  
Star Forming ◽  
Methanol Maser ◽  
Preliminary Results ◽  
Main Target ◽  
Maser Line ◽  
Source Structure

AbstractWe present preliminary results of the high resolution (0.10″ × 0.15″) observations of the high mass star forming region S255IR with ALMA in several spectral windows from ∼335 GHz to ∼350 GHz. The main target lines were C34S(7–6), CH3CN(19K − 18K), CO(3–2) and SiO(8–7), however many other lines of various molecules have been detected, too. We present sample spectra and maps, discuss briefly the source structure and kinematics. A new, never predicted methanol maser line has been discovered.

scholarly journals GASTON: Galactic Star Formation with NIKA2. Evidence for the mass growth of star-forming clumps

2021 ◽  
Author(s):  
A J Rigby ◽  
N Peretto ◽  
R Adam ◽  
P Ade ◽  
M Anderson ◽  
...  
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Galactic Plane ◽  
High Sensitivity ◽  
High Mass ◽  
Evolutionary Stage ◽  
Mass Star ◽  
Mass Growth ◽  
Star Forming ◽  
Compact Source

Abstract Determining the mechanism by which high-mass stars are formed is essential for our understanding of the energy budget and chemical evolution of galaxies. By using the New IRAM KIDs Array 2 (NIKA2) camera on the Institut de Radio Astronomie Millimétrique (IRAM) 30-m telescope, we have conducted high-sensitivity and large-scale mapping of a fraction of the Galactic plane in order to search for signatures of the transition between the high- and low-mass star-forming modes. Here, we present the first results from the Galactic Star Formation with NIKA2 (GASTON) project, a Large Programme at the IRAM 30-m telescope which is mapping ≈2 deg2 of the inner Galactic plane (GP), centred on ℓ = 23${_{.}^{\circ}}$9, b = 0${_{.}^{\circ}}$05, as well as targets in Taurus and Ophiuchus in 1.15 and 2.00 mm continuum wavebands. In this paper we present the first of the GASTON GP data taken, and present initial science results. We conduct an extraction of structures from the 1.15 mm maps using a dendrogram analysis and, by comparison to the compact source catalogues from Herschel survey data, we identify a population of 321 previously-undetected clumps. Approximately 80 per cent of these new clumps are 70 μm-quiet, and may be considered as starless candidates. We find that this new population of clumps are less massive and cooler, on average, than clumps that have already been identified. Further, by classifying the full sample of clumps based upon their infrared-bright fraction – an indicator of evolutionary stage – we find evidence for clump mass growth, supporting models of clump-fed high-mass star formation.

scholarly journals Looking for outflow and infall signatures in high-mass star-forming regions

2012 ◽  
Vol 538 ◽  
pp. A140 ◽  
Author(s):  
P. D. Klaassen ◽  
L. Testi ◽  
H. Beuther
Keyword(s):  
High Mass ◽  
Mass Star ◽  
Star Forming ◽  
Star Forming Regions

scholarly journals Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

2018 ◽  
Vol 609 ◽  
pp. A129 ◽  
Author(s):  
L. Colzi ◽  
F. Fontani ◽  
P. Caselli ◽  
C. Ceccarelli ◽  
P. Hily-Blant ◽  
...  
Keyword(s):  
Solar System ◽  
Solar Nebula ◽  
Rotational Transition ◽  
High Mass ◽  
Evolutionary Stage ◽  
Mass Star ◽  
Stellar Cluster ◽  
Star Forming ◽  
Star Forming Regions ◽  
Dense Cores

The ratio between the two stable isotopes of nitrogen, 14N and 15N, is well measured in the terrestrial atmosphere (~272), and for the pre-solar nebula (~441, deduced from the solar wind). Interestingly, some pristine solar system materials show enrichments in 15N with respect to the pre-solar nebula value. However, it is not yet clear if and how these enrichments are linked to the past chemical history because we have only a limited number of measurements in dense star-forming regions. In this respect, dense cores, which are believed to be the precursors of clusters and also contain intermediate- and high-mass stars, are important targets because the solar system was probably born within a rich stellar cluster, and such clusters are formed in high-mass star-forming regions. The number of observations in such high-mass dense cores has remained limited so far. In this work, we show the results of IRAM-30 m observations of the J = 1−0 rotational transition of the molecules HCN and HNC and their 15N-bearing counterparts towards 27 intermediate- and high-mass dense cores that are divided almost equally into three evolutionary categories: high-mass starless cores, high-mass protostellar objects, and ultra-compact Hii regions. We have also observed the DNC(2–1) rotational transition in order to search for a relation between the isotopic ratios D/H and 14N/15N. We derive average 14N/15N ratios of 359 ± 16 in HCN and of 438 ± 21 in HNC, with a dispersion of about 150–200. We find no trend of the 14N/15N ratio with evolutionary stage. This result agrees with what has been found for N2H+ and its isotopologues in the same sources, although the 14N/15N ratios from N2H+ show a higher dispersion than in HCN/HNC, and on average, their uncertainties are larger as well. Moreover, we have found no correlation between D/H and 14N/15N in HNC. These findings indicate that (1) the chemical evolution does not seem to play a role in the fractionation of nitrogen, and that (2) the fractionation of hydrogen and nitrogen in these objects is not related.

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