74
74
Jul 20, 2013
07/13
by
K. Justtanont; L. Decin; F. L. Schoier; M. Maercker; H. Olofsson; V. Bujarrabal; A. P. Marston; D. Teyssier; J. Alcolea; J. Cernicharo; C. Dominik; A. de Koter; G. Melnick; K. Menten; D. Neufeld; P. Planesas; M. Schmidt; R. Szczerba; R. Waters; Th. de Graauw; N. Whyborn; T. Finn; F. Helmich; O. Siebertz; F. Schmulling; V. Ossenkopf; R. Lai
texts
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A set of new, sensitive, and spectrally resolved, sub-millimeter line observations are used to probe the warm circumstellar gas around the S-type AGB star chi Cyg. The observed lines involve high rotational quantum numbers, which, combined with previously obtained lower-frequency data, make it possible to study in detail the chemical and physical properties of, essentially, the entire circumstellar envelope of chi Cyg. The data were obtained using the HIFI instrument aboard Herschel, whose high...
Source: http://arxiv.org/abs/1007.1536v1
4
4.0
Jun 30, 2018
06/18
by
L. Decin; A. M. S. Richards; D. Neufeld; W. Steffen; G. Melnick; R. Lombaert
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eye 4
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(abbreviated) We aim to study the inner wind of the well-known AGB star CW Leo. Different diagnostics probing different geometrical scales have pointed toward a non-homogeneous mass-loss process: dust clumps are observed at milli-arcsec scale, a bipolar structure is seen at arcsecond-scale and multi-concentric shells are detected beyond 1". We present the first ALMA Cycle 0 band 9 data around 650 GHz. The full-resolution data have a spatial resolution of 0".42x0".24, allowing us...
Topics: Astrophysics, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1410.2060
11
11
Jun 30, 2018
06/18
by
A. M. S. Richards; C. M. V. Impellizzeri; E. M. Humphreys; C. Vlahakis; W. Vlemmings; A. Baudry; E. De Beck; L. Decin; S. Etoka; M. D. Gray; G. M. Harper; T. R. Hunter; P. Kervella; F. Kerschbaum; I. McDonald; G. Melnick; S. Muller; D. Neufeld; E. O'Gorman; S. Yu. Parfenov; A. B. Peck; H. Shinnaga; A. M. Sobolev; L. Testi; L. Uscanga; A. Wootten; J. A. Yates; A. Zijlstra
texts
eye 11
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Cool, evolved stars have copious, enriched winds. The structure of these winds and the way they are accelerated is not well known. We need to improve our understanding by studying the dynamics from the pulsating stellar surface to about 10 stellar radii, where radiation pressure on dust is fully effective. Some red supergiants have highly asymmetric nebulae, implicating additional forces. We retrieved ALMA Science Verification data providing images of sub-mm line and continuum emission from VY...
Topics: Astrophysics, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1409.5497
50
50
Sep 23, 2013
09/13
by
B. Lefloch; S. Cabrit; C. Codella; G. Melnick; J. Cernicharo; E. Caux; M. Benedettini; A. Boogert; P. Caselli; C. Ceccarelli; F. Gueth; P. Hily-Blant; A. Lorenzani; D. Neufeld; B. Nisini; S. Pacheco; L. Pagani; J. R. Pardo; B. Parise; M. Salez; K. Schuster; S. Viti; A. Bacmann; A. Baudry; T. Bell; E. A. Bergin; G. Blake; S. Bottinelli; A. Castets; C. Comito; A. Coutens; N. Crimier; C. Dominik; K. Demyk; P. Encrenaz; E. Falgarone; A. Fuente; M. Gerin; P. Goldsmith; F. Helmich; P. Hennebelle; T....
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eye 50
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The outflow driven by the low-mass class 0 protostar L1157 is the prototype of the so-called chemically active outflows. The bright bowshock B1 in the southern outflow lobe is a privileged testbed of magneto-hydrodynamical (MHD) shock models, for which dynamical and chemical processes are strongly interdependent. We present the first results of the unbiased spectral survey of the L1157-B1 bowshock, obtained in the framework of the key program "Chemical Herschel Surveys of Star Forming...
Source: http://arxiv.org/abs/1006.1305v2
4
4.0
Jun 29, 2018
06/18
by
R. Lombaert; L. Decin; P. Royer; A. de Koter; N. L. J. Cox; E. González-Alfonso; D. Neufeld; J. De Ridder; M. Agúndez; J. A. D. L. Blommaert; T. Khouri; M. A. T. Groenewegen; F. Kerschbaum; J. Cernicharo; B. Vandenbussche; C. Waelkens
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eye 4
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Context. The recent detection of warm H$_2$O vapor emission from the outflows of carbon-rich asymptotic giant branch (AGB) stars challenges the current understanding of circumstellar chemistry. Two mechanisms have been invoked to explain warm H$_2$O vapor formation. In the first, periodic shocks passing through the medium immediately above the stellar surface lead to H$_2$O formation. In the second, penetration of ultraviolet interstellar radiation through a clumpy circumstellar medium leads to...
Topics: Astrophysics, Solar and Stellar Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1601.07017
Although soil nitrification has been studied intensively, with an effort to elucidate the relative contributions of both ammonia-oxidizing archaea (AOA) and bacteria (AOB), their relative contributions to N2O production remain unclear. Understanding the temperature- and depth-dependent activities of AOA and AOB, as well as production of N2O, is of great importance for predicting their responses to climate change. This work applied the recently discovered AOB inhibitor, octyne, to soil...
Topics: Agriculture, Ammonia oxidation, Nitrous oxide, Soil, Temperature
4
4.0
Jun 30, 2018
06/18
by
J. Cernicharo; D. Teyssier; G. Quintana-Lacaci; F. Daniel; M. Agúndez; L. Velilla Prieto; L. Decin; M. Guélin; P. Encrenaz; P. García-Lario; E. de Beck; M. J. Barlow; M. A. T. Groenewegen; D. Neufeld; J. Pearson
texts
eye 4
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We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species towards the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the HIFI instrument on board \textit{Herschel}\thanks{\textit{Herschel} is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA} and with the IRAM\thanks{This work was based on...
Topics: Astrophysics, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1410.5852
55
55
Jul 20, 2013
07/13
by
A. Bacmann; E. Caux; P. Hily-Blant; B. Parise; L. Pagani; S. Bottinelli; S. Maret; C. Vastel; C. Ceccarelli; J. Cernicharo; T. Henning; A. Castets; A. Coutens; E. A. Bergin; G. A. Blake; N. Crimier; K. Demyk; C. Dominik; M. Gerin; P. Hennebelle; C. Kahane; A. Klotz; G. Melnick; P. Schilke; V. Wakelam; A. Walters; A. Baudry; T. Bell; M. Benedettini; A. Boogert; S. Cabrit; P. Caselli; C. Codella; C. Comito; P. Encrenaz; E. Falgarone; A. Fuente; P. F. Goldsmith; F. Helmich; E. Herbst; T. Jacq; M....
texts
eye 55
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In the past decade, much progress has been made in characterising the processes leading to the enhanced deuterium fractionation observed in the ISM and in particular in the cold, dense parts of star forming regions such as protostellar envelopes. Very high molecular D/H ratios have been found for saturated molecules and ions. However, little is known about the deuterium fractionation in radicals, even though simple radicals often represent an intermediate stage in the formation of more complex,...
Source: http://arxiv.org/abs/1007.4691v1
5
5.0
Jun 30, 2018
06/18
by
G. Santangelo; S. Antoniucci; B. Nisini; C. Codella; P. Bjerkeli; T. Giannini; A. Lorenzani; L. K. Lundin; S. Cabrit; L. Calzoletti; R. Liseau; D. Neufeld; M. Tafalla; E. F. van Dishoeck
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eye 5
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Context: Herschel observations suggest that the H$_2$O distribution in outflows from low-mass stars resembles the H$_2$ emission. It is still unclear which of the different excitation components that characterise the mid- and near-IR H$_2$ distribution is associated with H$_2$O. Aim: The aim is to spectrally resolve the different excitation components observed in the H$_2$ emission. This will allow us to identify the H$_2$ counterpart associated with H$_2$O and finally derive directly an H$_2$O...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1409.2779
53
53
Sep 18, 2013
09/13
by
P. Bjerkeli; R. Liseau; B. Larsson; G. Rydbeck; B. Nisini; M. Tafalla; S. Antoniucci; M. Benedettini; P. Bergman; S. Cabrit; T. Giannini; G. Melnick; D. Neufeld; G. Santangelo; E. F. van Dishoeck
texts
eye 53
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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 gas, however, are not fully understood yet. We aim to determine the abundance and distribution of H2O, its kinematics and the physical conditions of the gas responsible for the H2O emission. The observed line profile shapes help us understand the dynamics in...
Source: http://arxiv.org/abs/1209.0294v1
41
41
Sep 21, 2013
09/13
by
D. Johnstone; M. Fich; C. McCoey; T. A. van Kempen; A. Fuente; L. E. Kristensen; J. Cernicharo; P. Caselli; R. Visser; R. Plume; G. J. Herczeg; E. F. van Dishoeck; S. Wampfler; R. Bachiller; A. Baudry; M. Benedettini; E. Bergin; A. O. Benz; P. Bjerkeli; G. Blake; S. Bontemps; J. Braine; S. Bruderer; C. Codella; F. Daniel; A. M. di Giorgio; C. Dominik; S. D. Doty; P. Encrenaz; T. Giannini; J. R. Goicoechea; Th. de Graauw; F. Helmich; F. Herpin; M. R. Hogerheijde; T. Jacq; J. K. Jørgensen; B....
texts
eye 41
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HERSCHEL-HIFI observations of water from the intermediate mass protostar NGC7129 FIRS 2 provide a powerful diagnostic of the physical conditions in this star formation environment. Six spectral settings, covering four H216O and two H218O lines, were observed and all but one H218O line were detected. The four H2 16 O lines discussed here share a similar morphology: a narrower, \approx 6 km/s, component centered slightly redward of the systemic velocity of NGC7129 FIRS 2 and a much broader,...
Source: http://arxiv.org/abs/1008.1254v1
56
56
Sep 21, 2013
09/13
by
M. Agundez; J. Cernicharo; L. B. F. M. Waters; L. Decin; P. Encrenaz; D. Neufeld; D. Teyssier; F. Daniel
texts
eye 56
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We report the detection of emission in the J=1-0 rotational transition of hydrogen fluoride (HF), together with observations of the J=1-0 to J=3-2 rotational lines of H35Cl and H37Cl, towards the envelope of the carbon star IRC +10216. High-sensitivity, high-spectral resolution observations have been carried out with the HIFI instrument on board Herschel, allowing us to resolve the line profiles and providing insights into the spatial distribution of the emission. Our interpretation of the...
Source: http://arxiv.org/abs/1108.4610v1
54
54
Jul 20, 2013
07/13
by
S. F. Wampfler; G. J. Herczeg; S. Bruderer; A. O. Benz; E. F. van Dishoeck; L. E. Kristensen; R. Visser; S. D. Doty; M. Melchior; T. A. van Kempen; U. A. Yildiz; C. Dedes; J. R. Goicoechea; A. Baudry; G. Melnick; R. Bachiller; M. Benedettini; E. Bergin; P. Bjerkeli; G. A. Blake; S. Bontemps; J. Braine; P. Caselli; J. Cernicharo; C. Codella; F. Daniel; A. M. di Giorgio; C. Dominik; P. Encrenaz; M. Fich; A. Fuente; T. Giannini; Th. de Graauw; F. Helmich; F. Herpin; T. Jacq; D. Johnstone; J. K. J...
texts
eye 54
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Water in Star-forming regions with Herschel (WISH) is a Herschel Key Program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of...
Source: http://arxiv.org/abs/1007.2198v1
87
87
Jul 20, 2013
07/13
by
S. Bruderer; A. O. Benz; E. F. van Dishoeck; M. Melchior; S. D. Doty; F. van der Tak; P. Stäuber; S. F. Wampfler; C. Dedes; U. A. Yıldız; L. Pagani; T. Giannini; Th. de Graauw; N. Whyborn; D. Teyssier; W. Jellema; R. Shipman; R. Schieder; N. Honingh; E. Caux; W. Bächtold; A. Csillaghy; C. Monstein; R. Bachiller; A. Baudry; M. Benedettini; E. Bergin; P. Bjerkeli; G. A. Blake; S. Bontemps; J. Braine; P. Caselli; J. Cernicharo; C. Codella; F. Daniel; A. M. di Giorgio; C. Dominik; P. Encrenaz;...
texts
eye 87
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The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+ and SH+ have not been detected. All molecules except for CH and CH+ are seen in absorption with low excitation...
Source: http://arxiv.org/abs/1007.3408v1
48
48
Sep 21, 2013
09/13
by
U. A. Yıldız; E. F. van Dishoeck; L. E. Kristensen; R. Visser; J. K. Jørgensen; G. J. Herczeg; T. A. van Kempen; M. R. Hogerheijde; S. D. Doty; A. O. Benz; S. Bruderer; S. F. Wampfler; E. Deul; R. Bachiller; A. Baudry; M. Benedettini; E. Bergin; P. Bjerkeli; G. A. Blake; S. Bontemps; J. Braine; P. Caselli; J. Cernicharo; C. Codella; F. Daniel; A. M. di Giorgio; C. Dominik; P. Encrenaz; M. Fich; A. Fuente; T. Giannini; J. R. Goicoechea; Th. de Graauw; F. Helmich; F. Herpin; T. Jacq; D....
texts
eye 48
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Herschel-HIFI observations of high-J lines (up to J_u=10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally-resolved HIFI data are complemented by ground-based observations of lower-J CO and isotopologue lines. The 12CO 10-9 profiles are dominated by broad (FWHM 25-30 km s^-1) emission. Radiative transfer models are...
Source: http://arxiv.org/abs/1008.0867v2
46
46
Sep 23, 2013
09/13
by
K. Justtanont; T. Khouri; M. Maercker; J. Alcolea; L. Decin; H. Olofsson; A. P. Marston; D. Teyssier; J. Cernicharo; C. Dominik; A. de Koter; G. Melnick; K. M. Menten; D. Neufeld; P. Planesas; M. Schmidt; R. Szczerba; R. Waters
texts
eye 46
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Spectra, taken with the heterodyne instrument, HIFI, aboard the Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part of the guaranteed time key program HIFISTARS are presented. The aim of this program is to study the dynamical structure, mass-loss driving mechanism, and chemistry of the outflows from AGB stars as a function of chemical composition and initial mass. We used the HIFI instrument to observe nine AGB stars, mainly in the H2O and high rotational...
Source: http://arxiv.org/abs/1111.5156v1
60
60
Jul 20, 2013
07/13
by
M. H. D. van der Wiel; F. F. S. van der Tak; D. C. Lis; T. Bell; E. A. Bergin; C. Comito; M. Emprechtinger; P. Schilke; E. Caux; C. Ceccarelli; A. Baudry; P. F. Goldsmith; E. Herbst; W. Langer; S. Lord; D. Neufeld; J. Pearson; T. Philips; R. Rolffs; H. Yorke; A. Bacmann; M. Benedettini; G. A. Blake; A. Boogert; S. Bottinelli; S. Cabrit; P. Caselli; A. Castets; J. Cernicharo; C. Codella; A. Coutens; N. Crimier; K. Demyk; C. Dominik; P. Encrenaz; E. Falgarone; A. Fuente; M. Gerin; F. Helmich; P....
texts
eye 60
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In contrast to extensively studied dense star-forming cores, little is known about diffuse gas surrounding star-forming regions. We study molecular gas in the high-mass star-forming region NGC6334I, which contains diffuse, quiescent components that are inconspicuous in widely used molecular tracers such as CO. We present Herschel/HIFI observations of CH toward NGC6334I observed as part of the CHESS key program. HIFI resolves the hyperfine components of its J=3/2-1/2 transition, observed in both...
Source: http://arxiv.org/abs/1007.1539v3
94
94
Jul 19, 2013
07/13
by
W. J. Fischer; S. T. Megeath; Babar Ali; J. J. Tobin; M. Osorio; L. E. Allen; E. Kryukova; T. Stanke; A. M. Stutz; E. Bergin; N. Calvet; J. Di Francesco; E. Furlan; L. Hartmann; T. Henning; O. Krause; P. Manoj; S. Maret; J. Muzerolle; P. Myers; D. Neufeld; K. Pontoppidan; C. A. Poteet; D. M. Watson; T. Wilson
texts
eye 94
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We present 70 and 160 micron Herschel science demonstration images of a field in the Orion A molecular cloud that contains the prototypical Herbig-Haro objects HH 1 and 2, obtained with the Photodetector Array Camera and Spectrometer (PACS). These observations demonstrate Herschel's unprecedented ability to study the rich population of protostars in the Orion molecular clouds at the wavelengths where they emit most of their luminosity. The four protostars previously identified by Spitzer 3.6-40...
Source: http://arxiv.org/abs/1005.2183v1
114
114
Jul 19, 2013
07/13
by
T. Stanke; A. M. Stutz; J. J. Tobin; B. Ali; S. T. Megeath; O. Krause; H. Linz; L. Allen; E. Bergin; N. Calvet; J. Di Francesco; W. J. Fischer; E. Furlan; L. Hartmann; T. Henning; P. Manoj; S. Maret; J. Muzerolle; P. C. Myers; D. Neufeld; M. Osorio; K. Pontoppidan; C. A. Poteet; D. M. Watson; T. Wilson
texts
eye 114
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The NGC 1999 reflection nebula features a dark patch with a size of ~10,000 AU, which has been interpreted as a small, dense foreground globule and possible site of imminent star formation. We present Herschel PACS far-infrared 70 and 160mum maps, which reveal a flux deficit at the location of the globule. We estimate the globule mass needed to produce such an absorption feature to be a few tenths to a few Msun. Inspired by this Herschel observation, we obtained APEX LABOCA and SABOCA...
Source: http://arxiv.org/abs/1005.2202v1
7
7.0
Jun 30, 2018
06/18
by
B. Winkel; H. Wiesemeyer; K. M. Menten; M. Sato; A. Brunthaler; F. Wyrowski; D. Neufeld; M. Gerin; N. Indriolo
texts
eye 7
favorite 0
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Recent submillimeter and far-infrared wavelength observations of absorption in the rotational ground-state lines of various simple molecules against distant Galactic continuum sources have opened the possibility of studying the chemistry of diffuse molecular clouds throughout the Milky Way. In order to calculate abundances, the column densities of molecular and atomic hydrogen, HI, must be known. We aim at determining the atomic hydrogen column densities for diffuse clouds located on the sight...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1702.05956
38
38
Sep 22, 2013
09/13
by
B. Nisini; G. Santangelo; S. Antoniucci; M. Benedettini; C. Codella; T. Giannini; A. Lorenzani; R. Liseau; M. Tafalla; P. Bjerkeli; S. Cabrit; P. Caselli; L. Kristensen; D. Neufeld; G. Melnick; E. F. van Dishoeck
texts
eye 38
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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 Herschel-HIFI and PACS instruments, respectively. Water emission appears clumpy, with individual peaks corresponding to shock spots along the outflow. The bulk of the 557 GHz line is confined to radial velocities in the range \pm 10-50 km/s but extended...
Source: http://arxiv.org/abs/1210.7178v1
47
47
Jul 19, 2013
07/13
by
T. A. van Kempen; L. E. Kristensen; G. J. Herczeg; R. Visser; E. F. van Dishoeck; S. F. Wampfler; S. Bruderer; A. O. Benz; S. D. Doty; C. Brinch; M. R. Hogerheijde; J. K. Jørgensen; M. Tafalla; D. Neufeld; R. Bachiller; A. Baudry; M. Benedettini; E. A. Bergin; P. Bjerkeli; G. A. Blake; S. Bontemps; J. Braine; P. Caselli; J. Cernicharo; C. Codella; F. Daniel; A. M. di Giorgio; C. Dominik; P. Encrenaz; M. Fich; A. Fuente; T. Giannini; J. R. Goicoechea; Th. de Graauw; F. Helmich; F. Herpin; T....
texts
eye 47
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'Water in Star-forming regions with Herschel' (WISH) is a Herschel Key Programme aimed at understanding the physical and chemical structure of young stellar objects (YSOs) with a focus on water and related species. The low-mass protostar HH 46 was observed with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory to measure emission in H2O, CO, OH, [OI], and [CII] lines located between 63 and 186 um. The excitation and spatial distribution of emission can...
Source: http://arxiv.org/abs/1005.2031v1
85
85
Jul 20, 2013
07/13
by
C. Vastel; C. Ceccarelli; E. Caux; A. Coutens; J. Cernicharo; S. Bottinelli; K. Demyk; A. Faure; L. Wiesenfeld; Y. Scribano; A. Bacmann; P. Hily-Blant; S. Maret; A. Walters; E. A. Bergin; G. A. Blake; A. Castets; N. Crimier; C. Dominik; P. Encrenaz; M. Gérin; P. Hennebelle; C. Kahane; A. Klotz; G. Melnick; L. Pagani; B. Parise; P. Schilke; V. Wakelam; A. Baudry; T. Bell; M. Benedettini; A. Boogert; S. Cabrit; P. Caselli; C. Codella; C. Comito; E. Falgarone; A. Fuente; P. F. Goldsmith; F....
texts
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Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star forming regions, and in particular the Class 0 protostar IRAS 16293-2422. The CHESS (Chemical HErschel Surveys of Star forming regions) Key Program aims at studying the molecular complexity of the interstellar medium. The high sensitivity and spectral resolution of the HIFI instrument provide a unique opportunity to observe the fundamental 1,1,1 - 0,0,0...
Source: http://arxiv.org/abs/1007.4410v1
100
100
Jul 20, 2013
07/13
by
E. A. Bergin; M. R. Hogerheijde; C. Brinch; J. Fogel; U. A. Yildiz; L. E. Kristensen; E. F. van~Dishoeck; T. A. Bell; G. A. Blake; J. Cernicharo; C. Dominik; D. Lis; G. Melnick; D. Neufeld; O. Panic; J. C. Pearson; R. Bachiller; A. Baudry; M. Benedettini; A. O. Benz; P. Bjerkeli; S. Bontemps; J. Braine; S. Bruderer; P. Caselli; C. Codella; F. Daniel; A. M. di Giorgio; S. D. Doty; P. Encrenaz; M. Fich; A. Fuente; T. Giannini; J. R. Goicoechea; Th. de Graauw; F. Helmich; G. J. Herczeg; F. Herpin;...
texts
eye 100
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We performed a sensitive search for the ground-state emission lines of ortho- and para-water vapor in the DM Tau protoplanetary disk using the Herschel/HIFI instrument. No strong lines are detected down to 3sigma levels in 0.5 km/s channels of 4.2 mK for the 1_{10}--1_{01} line and 12.6 mK for the 1_{11}--0_{00} line. We report a very tentative detection, however, of the 1_{10}--1_{01} line in the Wide Band Spectrometer, with a strength of T_{mb}=2.7 mK, a width of 5.6 km/s and an integrated...
Source: http://arxiv.org/abs/1007.2129v1
50
50
Sep 21, 2013
09/13
by
T. Giannini; B. Nisini; D. Neufeld; Y. Yuan; S. Antoniucci; A. Gusdorf
texts
eye 50
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Spitzer-IRS maps of H_2 pure rotational lines from S(0) to S(7) in 3 outflows from Class 0 sources - L1448, BHR71, and NGC2071 - are presented. These lines are used, in conjunction with available rovibrational, near-IR H_2 lines, to probe the physical conditions of the warm gas between hundreds and thousands of Kelvin. We have constructed maps of the molecular hydrogen column density, ortho-to-para ratio and volume density, together with the index beta of the power law describing the...
Source: http://arxiv.org/abs/1106.2722v1
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59
Jul 20, 2013
07/13
by
E. Falgarone; V. Ossenkopf; M. Gerin; P. Lesaffre; B. Godard; J. Pearson; S. Cabrit; Ch. Joblin; A. O. ~Benz; F. Boulanger; A. Fuente; R. Güsten; A. Harris; T. Klein; C. Kramer; S. Lord; P. Martin; J. Martin-Pintado; D. Neufeld; T. G. ~Phillips; M. Röllig; R. Simon; J. Stutzki; F. van der Tak; D. Teyssier; H. Yorke; N. Erickson; M. Fich; W. Jellema; A. Marston; C. Risacher; M. Salez; F. Schmülling
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We report the first detection of the ground-state rotational transition of the methylidyne cation CH+ towards the massive star-forming region DR21 with the HIFI instrument onboard the Herschel satellite. The line profile exhibits a broad emission line, in addition to two deep and broad absorption features associated with the DR21 molecular ridge and foreground gas. These observations allow us to determine a CH+ J=1-0 line frequency of 835137 +/- 3 MHz, in good agreement with a recent...
Source: http://arxiv.org/abs/1007.1420v1
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45
Sep 20, 2013
09/13
by
David Hollenbach; M. J. Kaufman; D. Neufeld; M. Wolfire; J. R. Goicoechea
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We model the production of OH+, H2O+, and H3O+ in interstellar clouds, using a steady state photodissociation region code that treats the freeze-out of gas species, grain surface chemistry, and desorption of ices from grains. The code includes PAHs, which have important effects on the chemistry. All three ions generally have two peaks in abundance as a function of depth into the cloud, one at A_V
Source: http://arxiv.org/abs/1205.6446v1
78
78
Jul 20, 2013
07/13
by
M. Emprechtinger; D. C. Lis; T. Bell; T. G. Phillips; P. Schilke; C. Comito; R. Rolffs; F. van der Tak; C. Ceccarelli; H. Aarts; A. Bacmann; A. Baudry; M. Benedettini; E. A. Bergin; G. Blake; A. Boogert; S. Bottinelli; S. Cabrit; P. Caselli; A. Castets; E. Caux; J. Cernicharo; C. Codella; A. Coutens; N. Crimier; K. Demyk; C. Dominik; P. Encrenaz; E. Falgarone; A. Fuente; M. Gerin; P. Goldsmith; F. Helmich; P. Hennebelle; T. Henning; E. Herbst; P. Hily-Blant; T. Jacq; C. Kahane; M. Kama; A....
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We present observations of twelve rotational transitions of H2O-16, H2O-18, and H2O-17 toward the massive star-forming region NGC 6334 I, carried out with Herschel/HIFI as part of the guaranteed time key program Chemical HErschel Surveys of Star forming regions (CHESS). We analyze these observations to obtain insights into physical processes in this region. We identify three main gas components (hot core, cold foreground, and outflow) in NGC 6334 I and derive the physical conditions in these...
Source: http://arxiv.org/abs/1007.4226v1
51
51
Sep 18, 2013
09/13
by
N. Flagey; P. F. Goldsmith; D. C. Lis; M. Gerin; D. Neufeld; P. Sonnentrucker; M. De Luca; B. Godard; J. R. Goicoechea; R. Monje; T. G. Phillips
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eye 51
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We present Herschel/HIFI observations of nine transitions of \hho and \hheo towards six high-mass star-forming regions, obtained as part of the PRISMAS Key Program. Water vapor in translucent clouds is detected in absorption along every sightline. We derive the column density of \hho or \hheo for the lower energy level of each transition observed. The total water column density is about a few $10^{13} \rm{cm^{-2}}$. We find that the abundance of water relative to hydrogen nuclei is...
Source: http://arxiv.org/abs/1211.0367v1
60
60
Jul 19, 2013
07/13
by
B. Nisini; M. Benedettini; C. Codella; T. Giannini; R. Liseau; D. Neufeld; M. Tafalla; E. F. van Dishoeck; R. Bachiller; A. Baaudry; O. A. Benz; E. Bergin; P. Bjerkeli; G. Blake; S. Bontemps; J. Braine; S. Bruderer; P. Caselli; J. Cernicharo; F. Daniel; P. Encrenaz; A. M. di Giorgio; C. Dominik; S. Doty; M. Fich; A. Fuente; J. R. Goicoechea; Th. de Graaw; F. Helmich; G. Herczeg; F. Herpin; M. Hogerheijde; T. Jacq; D. Johnstone; J. Jorgensen; M. Kaufman; L. Kirstensen; B. Larsson; D. Lis; M....
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eye 60
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In the framework of the Water in Star-forming regions with Herschel (WISH) key program, maps in water lines of several outflows from young stars are being obtained, to study the water production in shocks and its role in the outflow cooling. This paper reports the first results of this program, presenting a PACS map of the o-H2O 179 um transition obtained toward the young outflow L1157. The 179 um map is compared with those of other important shock tracers, and with previous single-pointing...
Source: http://arxiv.org/abs/1005.4517v1
57
57
Jul 20, 2013
07/13
by
L. E. Kristensen; R. Visser; E. F. van Dishoeck; U. A. Yıldız; S. D. Doty; G. J. Herczeg; F. -C. Liu; B. Parise; J. K. Jørgensen; T. A. van Kempen; C. Brinch; S. F. Wampfler; S. Bruderer; A. O. Benz; M. R. Hogerheijde; E. Deul; R. Bachiller; A. Baudry; M. Benedettini; E. A. Bergin; P. Bjerkeli; G. A. Blake; S. Bontemps; J. Braine; P. Caselli; J. Cernicharo; C. Codella; F. Daniel; Th. de Graauw; A. M. di Giorgio; C. Dominik; P. Encrenaz; M. Fich; A. Fuente; T. Giannini; J. R. Goicoechea; F....
texts
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'Water In Star-forming regions with Herschel' (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the Far-Infrared (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC1333 in several H2-16O, H2-18O, and CO transitions. Line profiles are resolved for...
Source: http://arxiv.org/abs/1007.3031v1
9
9.0
Jun 30, 2018
06/18
by
M. Gerin; M. Ruaud; J. R. Goicoechea; A. Gusdorf; B. Godard; M. de Luca; E. Falgarone; P. F. Goldsmith; D. C. Lis; K. M. Menten; D. Neufeld; T. G. Phillips; H. Liszt
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eye 9
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Ionized carbon is the main gas-phase reservoir of carbon in the neutral diffuse interstellar medium and its 158 micron fine structure transition [CII] is the most important cooling line of the diffuse interstellar medium (ISM). We combine [CII] absorption and emission spectroscopy to gain an improved understanding of physical conditions in the different phases of the ISM. We present high resolution [CII] spectra obtained with the Herschel/HIFI instrument towards bright dust continuum sources...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1410.4663
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12
Jun 26, 2018
06/18
by
B. Nisini; G. Santangelo; T. Giannini; S. Antoniucci; S. Cabrit; C. Codella; C. J. Davis; J. Eisloeffel; L. Kristensen; G. Herczeg; D. Neufeld; E. F. van Dishoeck
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eye 12
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We present Herschel PACS mapping observations of the [OI]63 micron line towards protostellar outflows in the L1448, NGC1333-IRAS4, HH46, BHR71 and VLA1623 star forming regions. We detect emission spatially resolved along the outflow direction, which can be associated with a low excitation atomic jet. In the L1448-C, HH46 IRS and BHR71 IRS1 outflows this emission is kinematically resolved into blue- and red-shifted jet lobes, having radial velocities up to 200 km/s. In the L1448-C atomic jet the...
Topics: Astrophysics, Solar and Stellar Astrophysics
Source: http://arxiv.org/abs/1501.03681
