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Related papers: Water emission from the chemically rich outflow L1…

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(Abridged) We present a survey of the water emission in a sample of more than 20 outflows from low mass young stellar objects with the goal of characterizing the physical and chemical conditions of the emitting gas. We have used the HIFI…

Molecular outflows powered by young protostars strongly affect the kinematics and chemistry of the natal molecular cloud through strong shocks resulting in substantial modifications of the abundance of several species. As part of the…

As part of the WISH (Water In Star-forming regions with Herschel) key project, we report on the observations of several ortho- and para-H2O lines performed with the HIFI instrument towards two bright shock spots (R4 and B2) along the…

Herschel-HIFI observations of water in the low-mass star-forming object L1448-MM, known for its prominent outflow, are presented, as obtained within the `Water in star-forming regions with Herschel' (WISH) key programme. Six H2-16O lines…

Solar and Stellar Astrophysics · Physics 2015-05-28 L. E. Kristensen , E. F. van Dishoeck , M. Tafalla , R. Bachiller , B. Nisini , R. Liseau , U. A. Yildiz

We investigate on the spatial and velocity distribution of H2O along the L1448 outflow, its relationship with other tracers, and its abundance variations, using maps of the o-H2O 1_{10}-1_{01} and 2_{12}-1_{01} transitions taken with the…

(Abridged) Water is a key tracer of dynamics and chemistry in low-mass protostars, but spectrally resolved observations have so far been limited in sensitivity and angular resolution. In this first systematic survey of spectrally resolved…

Context: Existing SWAS observations and future HIFI/Herschel data require a clear sense of the information content of water emission and absorption lines. Aims: Investigate wether the ground-state transition of ortho-H2O, 1_(10)-1_(01), at…

Astrophysics · Physics 2009-11-11 D. R. Poelman , M. Spaans , A. G. G. M. Tielens

In the framework of the WISH key program, several H2O (E_u>190 K), high-J CO, [OI], and OH transitions are mapped with PACS in two shock positions along the two prototypical low-luminosity outflows L1448 and L1157. Previous HIFI H2O…

Astrophysics of Galaxies · Physics 2015-06-16 G. Santangelo , B. Nisini , S. Antoniucci , C. Codella , S. Cabrit , T. Giannini , G. Herczeg , R. Liseau , M. Tafalla , E. F. van Dishoeck

We investigate the physical and chemical processes at work during the formation of a massive protostar based on the observation of water in an outflow from a very young object previously detected in H2 and SiO in the IRAS 17233-3606 region.…

Astrophysics of Galaxies · Physics 2014-05-08 S. Leurini , A. Gusdorf , F. Wyrowski , C. Codella , T. Csengeri , F. van der Tak , H. Beuther , D. R. Flower , C. Comito , P. Schilke

Herschel-HIFI spectra of H2O towards low-mass protostars show a distinct velocity component not seen in observations from the ground of CO or other species. The aim is to characterise this component in terms of excitation conditions and…

Solar and Stellar Astrophysics · Physics 2015-06-16 L. E. Kristensen , E. F. van Dishoeck , A. O. Benz , S. Bruderer , R. Visser , S. F. Wampfler

Apart from being an important coolant, H2O is known to be a tracer of high-velocity molecular gas. Recent models predict relatively high abundances behind interstellar shockwaves. The dynamical and physical conditions of the H2O emitting…

Water probes the dynamics in young stellar objects (YSOs) effectively, especially shocks in molecular outflows. It is a key molecule for exploring whether the physical properties of low-mass protostars can be extrapolated to massive YSOs.…

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

(Abridged) Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. In this work we present spectro-imaging observations of the HH211 system…

Solar and Stellar Astrophysics · Physics 2018-08-22 Odysseas Dionatos , Tom Ray , Manuel Guedel

This paper reviews the first results of observations of H2O line emission with Herschel-HIFI towards high-mass star-forming regions, obtained within the WISH guaranteed time program. The data reveal three kinds of gas-phase H2O: `cloud…

Astrophysics of Galaxies · Physics 2019-08-14 Floris van der Tak , Fabrice Herpin , Friedrich Wyrowski

In a previous study of the L1157 B1 shocked cavity, a comparison between NH$_3$(1$_0$-$0_0$) and H$_2$O(1$_{\rm 10}$--1$_{\rm 01}$) transitions showed a striking difference in the profiles, with H$_2$O emitting at definitely higher…

We present the first results of the unbiased survey of the L1157-B1 bow shock, obtained with HIFI in the framework of the key program Chemical Herschel surveys of star forming regions (CHESS). The L1157 outflow is driven by a low-mass Class…

Astrophysics of Galaxies · Physics 2015-05-19 C. Codella , B. Lefloch , C. Ceccarelli , CHESS Team , HIFI Team
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