402 citations · 2.4k across the 37 of their papers we have counts for
22 papers · 1 filter
Episodic infall towards a compact disk in B335?
Per Bjerkeli, Jon P. Ramsey, Daniel Harsono +7
Previous observations of B335 have presented evidence of ongoing infall in various molecular lines, e.g., HCO, HCN, CO. There have been no confirmed observations of a rotationa…
The ALMA-PILS survey: Gas dynamics in IRAS 162932422 and the connection between its two protostars
M. H. D. van der Wiel, S. K. Jacobsen, J. K. Jørgensen +10
[Abridged] The majority of stars form in binary or higher order systems. The Class 0 protostellar system IRAS16293-2422 contains two protostars, 'A' and 'B', separated by ~600 au a…
The ALMA-PILS survey: Complex nitriles towards IRAS 16293--2422
H. Calcutt, J. K. Jørgensen, H. S. P. Müller +8
Complex organic molecules are readily detected in the inner regions of the gaseous envelopes of forming protostars. In particular, molecules that contain nitrogen are interesting d…
The ALMA-PILS survey: Formaldehyde deuteration in warm gas on small scales toward IRAS 16293-2422 B
M. V. Persson, J. K. Jørgensen, H. S. P. Müller +7
[abridged] The enhanced degrees of deuterium fractionation observed in envelopes around protostars demonstrate the importance of chemistry at low temperatures, relevant in pre- and…
Three-dimensional distribution of hydrogen fluoride gas toward NGC6334 I and I(N)
M. H. D. van der Wiel, D. A. Naylor, G. Makiwa +2
Aims. We investigate the spatial distribution of a collection of absorbing gas clouds, some associated with the dense, massive star-forming core NGC6334 I, and others with diffuse…
The Spatial Variation of the Cooling Lines in the Reflection Nebula NGC7023
J. Bernard-Salas, E. Habart, M. Köhler +7
Context: The north-west photo-dissociation region (PDR) in the reflection nebula NGC 7023 displays a complex structure. Filament-like condensations at the edge of the cloud can be…
The HIFI spectral survey of AFGL 2591 (CHESS). III. Chemical structure of the protostellar envelope
Maja Kazmierczak-Barthel, Dimitri Semenov, Floris van der Tak +2
We aim to understand the rich chemical composition of AFGL 2591, a prototypical isolated high-mass star-forming region. Based on HIFI and JCMT data, the molecular abundances of spe…
Physical structure of the photodissociation regions in NGC 7023. Observations of gas and dust emission with Herschel
M. Köhler, E. Habart, H. Arab +16
The determination of the physical conditions in molecular clouds is a key step towards our understanding of their formation and evolution of associated star formation. We investiga…
Signatures of warm carbon monoxide in protoplanetary discs observed with Herschel SPIRE
M. H. D. van der Wiel, D. A. Naylor, I. Kamp +9
Molecular gas constitutes the dominant mass component of protoplanetary discs. To date, these sources have not been studied comprehensively at the longest far-infrared and shortest…
Gas signatures of Herbig Ae/Be disks probed with Herschel SPIRE spectroscopy
Matthijs H. D. van der Wiel, David A. Naylor, Giambattista Aresu +1
Herbig Ae/Be objects, like their lower mass counterparts T Tauri stars, are seen to form a stable circumstellar disk which is initially gas-rich and could ultimately form a planeta…
Hydrogen Fluoride in High-Mass Star-forming Regions
Martin Emprechtinger, Raquel R. Monje, Floris F. S. van der Tak +5
Hydrogen fluoride has been established to be an excellent tracer of molecular hydrogen in diffuse clouds. In denser environments, however, the HF abundance has been shown to be app…
The JCMT Spectral Legacy Survey: physical structure of the molecular envelope of the high-mass protostar AFGL2591
M. H. D. van der Wiel, F. F. S. van der Tak, M. Spaans +4
The understanding of the formation process of massive stars (>8 Msun) is limited, due to theoretical complications and observational challenges. We investigate the physical structu…
Nitrogen hydrides in the cold envelope of IRAS16293-2422
Pierre Hily-Blant, Sébastien Maret, Aurore Bacmann +4
Nitrogen is the fifth most abundant element in the Universe, yet the gas-phase chemistry of N-bearing species remains poorly understood. Nitrogen hydrides are key molecules of nitr…
The methanol lines and hot core of OMC2-FIR4, an intermediate-mass protostar, with Herschel-HIFI
M. Kama, C. Dominik, S. Maret +61
In contrast with numerous studies on the physical and chemical structure of low- and high-mass protostars, much less is known about their intermediate-mass counterparts, a class of…
First detection of ND in the solar-mass protostar IRAS16293-2422
A. Bacmann, E. Caux, P. Hily-Blant +64
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, d…
Herschel/HIFI observations of spectrally resolved methylidyne signatures toward the high-mass star-forming core NGC6334I
M. H. D. van der Wiel, F. F. S. van der Tak, D. C. Lis +65
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-formin…
The distribution of water in the high-mass star-forming region NGC 6334I
M. Emprechtinger, D. C. Lis, T. Bell +66
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…
Herschel/HIFI discovery of interstellar chloronium (HCl)
D. C. Lis, J. C. Pearson, D. A. Neufeld +102
We report the first detection of chloronium, HCl, in the interstellar medium, using the HIFI instrument aboard the \emph{Herschel} Space Observatory. The li…
CHESS, Chemical Herschel surveys of star forming regions:Peering into the protostellar shock L1157-B1
B. Lefloch, S. Cabrit, C. Codella +74
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 pr…
The CHESS chemical Herschel surveys of star forming regions: Peering into the protostellar shock L1157-B1. I. Shock chemical complexity
C. Codella, B. Lefloch, C. Ceccarelli +2
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 regi…
Detection of interstellar oxidaniumyl: abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334
V. Ossenkopf, H. S. P. Müller, D. C. Lis +99
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 character…
Chemical stratification in the Orion Bar: JCMT Spectral Legacy Survey observations
Matthijs H. D. van der Wiel, Floris F. S. van der Tak, Volker Ossenkopf +4
Photon-dominated regions (PDRs) are expected to show a layered structure in molecular abundances and emerging line emission, which is sensitive to the physical structure of the reg…