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Related papers: Hydrides in Young Stellar Objects: Radiation trace…

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Using IRAM PdBI we report the detection of H2O in six new lensed ultra-luminous starburst galaxies at high redshift, discovered in the Herschel H-ATLAS survey. The sources are detected either in the 2_{02}-1_{11} or 2_{11}-2_{02} H_2O…

OH is a key species in the water chemistry of star-forming regions, because its presence is tightly related to the formation and destruction of water. This paper presents OH observations from 23 low- and intermediate-mass young stellar…

We present a catalogue of Molecular Hydrogen emission-line Objects (MHOs) in outflows from young stars, most of which are embedded. All objects are identified in the near-infrared lines of molecular hydrogen, all reside in the Milky Way,…

Solar and Stellar Astrophysics · Physics 2015-05-14 Christopher J. Davis , Ryan Gell , Tigran Khanzadyan , Michael D. Smith , Tim Jenness

The main accretion phase of protostars is characterized by the ejection of material in the form of jets/outflows. External UV irradiation can potentially have a significant impact on the excitation conditions within these outflows.…

(Abridged) We use HIFI maps of the 987 GHz H2O 2(02)-1(11) emission to measure the sizes and shapes of 19 high-mass protostellar envelopes. To identify infall, we use HIFI spectra of the optically thin C18O 9-8 and H2O-18 1(11)-0(00) lines.…

Astrophysics of Galaxies · Physics 2019-05-29 Floris van der Tak , Russ Shipman , Thierry Jacq , Fabrice Herpin , Jonathan Braine , Friedrich Wyrowski

Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds…

We present medium-resolution (R $\sim$ 4000) YJ, H \& K band spectroscopy of candidate young stellar objects (YSOs) in NGC~346, the most active star-formation region in the metal-poor (Z = 1/5 Z$_{\sun}$) Small Magellanic Cloud. The spectra…

Solar and Stellar Astrophysics · Physics 2022-09-14 O. C. Jones , M. Reiter , R. Sanchez-Janssen , C. J. Evans , C. S. Robertson , M. Meixner , B. Ochsendorf

The spatial distribution and evolution of gas in the inner 10 au of protoplanetary disks form the basis for estimating the initial conditions of planet formation. Among the most important constraints derived from spectroscopic observations…

The HyGAL Stratospheric Observatory for Infrared Astronomy (SOFIA) legacy program aims at characterizing the interstellar medium in the Milky Way using hydrides, [C II], and [O I] absorption lines with the 2.7 m SOFIA telescope toward…

Direct observations of accretion disks around high-mass young stellar objects would help to discriminate between different models of formation of massive stars. However, given the complexity of massive star forming regions, such studies are…

Solar and Stellar Astrophysics · Physics 2015-05-27 S. Leurini , C. Codella , L. Zapata , M. T. Beltran , P. Schilke , R. Cesaroni

The Ultra Luminous InfraRed Galaxy Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (E_{upper}=640 K) line detected at a 4sigma level, within the Herschel/SPIRE wavelength range, whereas…

We have observed the IC1396W globule in a narrow band filter centred on the 1-0 S(1) line of molecular hydrogen and in the J, H, K' broad-band filters. Three molecular hydrogen outflows could be identified by means of H2 emission. The…

Astrophysics · Physics 2009-11-07 D. Froebrich , A. Scholz

We report on the observation of hot water vapor (steam) in the inner AU of a young massive star located in the star-forming region IRAS 08576-4334. The water lines are detected in a medium resolution (R=10,000) K-band spectrum taken by the…

Astrophysics · Physics 2009-11-10 W. -F. Thi , A. Bik

We report a search for the diatomic hydrides SiH, PH, and FeH along the line of sight toward the chemically rich circumstellar envelopes of IRC+10216 and VY Canis Majoris. These molecules are thought to form in high temperature regions near…

Context - Circumstellar discs are ubiquitous around young stars, but rapidly dissipate their gas and dust on timescales of a few Myr. The Herschel space observatory allows for the study of the warm disc atmosphere, using far-infrared…

We present high resolution (R = 75,000-100,000) mid-infrared spectra of the high-mass embedded young star IRS 1 in the NGC 7538 star-forming region. Absorption lines from many rotational states of C2H2, 13C12CH2, CH3, CH4, NH3, HCN, HNCO,…

Astrophysics of Galaxies · Physics 2012-08-27 C. Knez , J. H. Lacy , N. J. Evans , II , E. F. van Dishoeck , M. J. Richter

We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin. The characteristic hyperfine pattern of the H2O+ ground-state rotational…

We present high angular resolution observations toward two massive star forming regions IRAS 18264-1152 and IRAS 23151+5912 with the Plateau de Bure Interferometer (PdBI) in the SiO (J=2-1) and H$^{13}$CO$^{+}$ (J=1-0) lines and at 1.3 mm…

Astrophysics · Physics 2008-11-26 Keping Qiu , Qizhou Zhang , Henrik Beuther , Ji Yang

The detection of narrow channels of accretion toward protostellar disks, known as streamers, have increased in number in the last few years. However, it is unclear if streamers are a common feature around protostars that were previously…

Single-dish spectra and interferometric maps of (sub)mm lines of H2O-18 and HDO are used to study the chemistry of water in eight regions of high-mass star formation. The spectra indicate HDO excitation temperatures of ~110 K and column…

Astrophysics · Physics 2009-11-11 Floris van der Tak , Malcolm Walmsley , Fabrice Herpin , Cecilia Ceccarelli