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Related papers: Shock-type inference of L1157 B2 using methanol de…

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I examine the role of dust grains in determining the structure of steady, cold, oblique C-type shocks in dense molecular gas. Gas pressure, the inertia of the charged components, and changes in ionisation are neglected. The grain charge and…

Astrophysics · Physics 2009-10-30 Mark Wardle

Methanol is a common component of interstellar and circumstellar ice mantles and is often used as an evolution indicator in star-forming regions. The observations of gas-phase methanol in the interiors of dense molecular clouds at…

Instrumentation and Methods for Astrophysics · Physics 2016-07-27 Gustavo A. Cruz-Diaz , Rafael Martín-Doménech , Guillermo M. Muñoz Caro , Y. -J. Chen

Observations of Serpens have been performed at the JCMT using Harp-B. Maps over a 4.5'x5.4' region were made in a frequency window around 338 GHz, covering the 7-6 transitions of methanol. Emission is extended over each source, following…

Solar and Stellar Astrophysics · Physics 2015-05-18 L. E. Kristensen , E. F. van Dishoeck , T. A. van Kempen , H. M. Cuppen , C. Brinch , J. K. Jørgensen , M. R. Hogerheijde

During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks…

We present an analysis of Spitzer-IRS spectroscopic maps of the L1157 protostellar outflow in the H2 pure-rotational lines from S(0) to S(7). The aim of this work is to derive the physical conditions pertaining to the warm molecular gas and…

Solar and Stellar Astrophysics · Physics 2015-05-20 B. Nisini , T. Giannini , D. A. Neufeld , Y. Yuan , S. Antoniucci , E. A. Bergin , G. J. Melnick

Outflows generated by protostars heavily affect the kinematics and chemistry of the hosting molecular cloud through strong shocks that enhance the abundance of some molecules. L1157 is the prototype of chemically active outflows, and a…

Despite its major role in the evolution of the interstellar medium, the formation of high-mass stars (M > 10 Msol) is still poorly understood. Two types of massive star cluster precursors, the so-called Massive Dense Cores (MDCs), have been…

Astrophysics of Galaxies · Physics 2015-05-19 M. G. Marseille , F. F. S. van der Tak , F. Herpin , T. Jacq

The shock L1157-B1 driven by the low-mass protostar L1157-mm is an unique environment to investigate the chemical enrichment due to molecules released from dust grains. IRAM-30m and Plateau de Bure Interferometer observations allow a census…

In the BHR71 region, two low-mass protostars drive two distinguishable outflows. They constitute an ideal laboratory to investigate the effects of shock chemistry and the mechanisms that led to their formation. We aim to define the…

Astrophysics of Galaxies · Physics 2017-02-01 M. Benedettini , A. Gusdorf , B. Nisini , B. Lefloch , S. Anderl , G. Busquet , C. Ceccarelli , C. Codella , S. Leurini , L. Podio

When a fast moving star or a protostellar jet hits an interstellar cloud, the surrounding gas gets heated and illuminated: a bow shock is born which delineates the wake of the impact. In such a process, the new molecules that are formed and…

Astrophysics of Galaxies · Physics 2017-11-27 L. N. Tram , P. Lesaffre , S. Cabrit , A. Gusdorf , P. T. Nhung

Sulfur-bearing molecules are highly reactive in the gas phase of the ISM. However, the form in which most of the sulfur is locked onto interstellar dust grains is unknown. By taking advantage of the short time-scales of shocks in young…

Shock modelling predicts an electron density enhancement within the magnetic precursor of C-shocks. Previous observations of SiO, H13CO+, HN13C and H13CN toward the young L1448-mm outflow showed an over-excitation of the ion fluid that was…

A survey of young bipolar outflows in regions of low-to-intermediate-mass star formation has been carried out in two class I methanol maser transitions: 7_0-6_1A+ at 44 GHz and 4_{-1}-3_0E at 36 GHz. We detected narrow features towards NGC…

Astrophysics of Galaxies · Physics 2015-05-18 S. V. Kalenskii , L. E. B. Johansson , P. Bergman , S. Kurtz , P. Hofner , C. M. Walmsley , V. I. Slysh

Methanol and complex organic molecules have been found in cold starless cores, where a standard warm-up scenario would not work because of the absence of heat sources. A recent chemical model attributed the presence of methanol and large…

Astrophysics of Galaxies · Physics 2021-07-14 Miwa Goto , A. I. Vasyunin , B. M. Giuliano , I. Jiménez-Serra , P. Caselli , C. G. Román-Zúñiga , J. Alves

Methanol is a key species in astrochemistry since it is the most abundant organic molecule in the ISM and is thought to be the mother molecule of many complex organic species. Estimating the deuteration of methanol around young protostars…

The circumstellar environments of objects on the asymptotic giant branch and beyond are rich in molecular species. Nevertheless, methanol has never been detected in such an object, and is therefore often taken as a clear signpost for a…

Solar and Stellar Astrophysics · Physics 2017-07-26 H. Olofsson , W. H. T. Vlemmings , P. Bergman , E. M. L. Humphreys , M. Lindqvist. M. Maercker , L. Nyman , S. Ramstedt , D. Tafoya

Shock waves in molecular clouds should evolve into continuous or C-type structures due to the magnetic field and ion-neutral friction. We here determine whether and how this is achieved through plane-parallel numerical simulations using an…

Astrophysics · Physics 2007-05-23 Michael D. Smith , Mordecai-Mark Mac Low

We report the detection of complex organic molecules in the young protostellar outflow L1157. We identify lines from HCOOCH3, CH3CN, HCOOH and C2H5OH at the position of the B1 shock in the blueshifted lobe, making it the first time that…

Context: Methanol masers of Class I (collisionally-pumped) and Class II (radiatively-pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are helpful…

Methanol is formed via surface reactions on icy dust grains. Methanol is also detected in the gas-phase at temperatures below its thermal desorption temperature and at levels higher than can be explained by pure gas-phase chemistry. The…

Solar and Stellar Astrophysics · Physics 2018-05-02 N. F. W. Ligterink , C. Walsh , R. G. Bhuin , S. Vissapragada , J. Terwisscha van Scheltinga , H. Linnartz