242 citations · 1.2k across the 27 of their papers we have counts for
27 papers
History of two mass loss processes in VY CMa. Fast outflows carving older ejecta
G. Quintana-Lacaci, L. Velilla-Prieto, M. Agúndez +4
Red supergiant stars (RSGs, Minit = 10-40Msun) are known to eject large amounts of material, as much as half of their initial mass during this evolutionary phase. However, the proc…
Water isotopologues in the circumstellar envelopes of M-type AGB stars
Taïssa Danilovich, R. Lombaert, L. Decin +3
AIM: In this study we examine rotational emission lines of two isotopologues of water: HO and HO. By determining the abundances of these molecules, we aim to…
On the properties of dust and gas in the environs of V838 Monocerotis
K. M. Exter, N. L. J. Cox, B. M. Swinyard +4
Herschel FIR imaging and spectroscopy were taken at several epochs to probe the central point source and the extended environment of V838 Mon. PACS and SPIRE maps were used to obta…
Herschel/HIFI observations of the circumstellar ammonia lines in IRC+10216
M. R. Schmidt, J. H. He, R. Szczerba +14
New high-resolution far-infrared (FIR) observations of both ortho- and para-NH3 transitions toward IRC+10216 were obtained with Herschel, with the goal of determining the ammonia a…
Study of the inner dust envelope and stellar photosphere of the AGB star R Doradus using SPHERE/ZIMPOL
T. Khouri, M. Maercker, L. B. F. M. Waters +12
We use high-angular-resolution images obtained with SPHERE/ZIMPOL to study the photosphere, the warm molecular layer, and the inner wind of the close-by oxygen-rich AGB star R Dora…
Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars
R. Lombaert, L. Decin, P. Royer +13
Context. The recent detection of warm HO vapor emission from the outflows of carbon-rich asymptotic giant branch (AGB) stars challenges the current understanding of circumstell…
Herschel observations of extreme OH/IR stars - the isotopic ratios of oxygen as a sign-post for the stellar mass
K. Justtanont, M. J. Barlow, J. Blommaert +10
Aim: The late stages of stellar evolution are mainly governed by the mass of the stars. Low- and intermediate-mass stars lose copious amounts of mass during the asymptotic giant br…
Dusty wind of W Hya. Multi-wavelength modelling of the present-day and recent mass-loss
T. Khouri, L. B. F. M. Waters, A. de Koter +5
Low- and intermediate-mass stars go through a period of intense mass-loss at the end of their lives in a phase known as the asymptotic giant branch (AGB). During the AGB a signific…
ALMA Observations of Anisotropic Dust Mass-loss in the Inner Circumstellar Environment of the Red Supergiant VY Canis Majoris
E. O'Gorman, W. Vlemmings, A. M. S. Richards +8
The processes leading to dust formation and the subsequent role it plays in driving mass loss in cool evolved stars is an area of intense study. Here we present high resolution ALM…
The wind of W Hya as seen by Herschel. II. The molecular envelope of W Hya
T. Khouri, A. de Koter, L. Decin +18
The evolution of low- and intermediate-mass stars on the asymptotic giant branch (AGB) is mainly controlled by the rate at which these stars lose mass in a stellar wind. Understand…
Confirmation of circumstellar phosphine
M. Agundez, J. Cernicharo, L. Decin +2
Phosphine (PH3) was tentatively identified a few years ago in the carbon star envelopes IRC+10216 and CRL2688 from observations of an emission line at 266.9 GHz attributable to the…
HIFISTARS Herschel/HIFI observations of VY Canis Majoris. Molecular-line inventory of the envelope around the largest known star
J. Alcolea, V. Bujarrabal, P. Planesas +16
To gain insight into the physical conditions and kinematics of the warm (100-1000 K) gas around the red hyper-giant VY CMa, we performed sensitive high spectral resolution observat…
Herschel/HIFI observations of red supergiants and yellow hypergiants: I. Molecular inventory
D. Teyssier, G. Quintana-Lacaci, A. P. Marston +17
Red supergiant stars (RSGs) and yellow hypergiant stars (YHGs) are believed to be the high-mass counterparts of stars in the AGB and early post-AGB phases. We study the mass-loss i…
Herschel/HIFI observation of highly excited rotational lines of HNC toward IRC +10 216
F. Daniel, M. Agúndez, J. Cernicharo +6
We report the detection in emission of various highly excited rotational transitions of HNC (J = 6-5 through J =12-11) toward the carbon-star envelope IRC +10 216 using the HIFI in…
On the physical structure of IRC+10216. Ground-based and Herschel observations of CO and CCH
E. De Beck, R. Lombaert, M. Agúndez +17
The C-rich AGB star IRC+10216 undergoes strong mass loss, and quasi-periodic density enhancements in the circumstellar matter have been reported. CO is ubiquitous in the CSE, while…
Spectroscopic parameters for silacyclopropynylidene, SiC, from extensive astronomical observations toward CW Leo (IRC +10216) with the Herschel satellite
H. S. P. Müller, J. Cernicharo, M. Agúndez +5
A molecular line survey has been carried out toward the carbon-rich asymptotic giant branch star CW Leo employing the HIFI instrument on board of the Herschel satellite. Numerous f…
Herschel/HIFI observations of O-rich AGB stars : molecular inventory
K. Justtanont, T. Khouri, M. Maercker +15
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…
Herschel/HIFI observations of molecular emission in protoplanetary nebulae and young planetary nebulae
V. Bujarrabal, J. Alcolea, R. Soria-Ruiz +1
We performed Herschel/HIFI observations of intermediate-excitation molecular lines in the far-infrared/submillimeter range in a sample of ten protoplanetary nebulae and young plane…
The widespread occurence of water vapor in the circumstellar envelopes of carbon-rich AGB stars: first results from a survey with Herschel/HIFI
D. A. Neufeld, E. González-Alfonso, G. Melnick +16
We report the preliminary results of a survey for water vapor in a sample of eight C stars with large mid-IR continuum fluxes: V384 Per, CIT 6, V Hya, Y CVn, IRAS 15194-5115, V Cyg…
Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles - II. CO line survey of evolved stars: derivation of mass-loss rate formulae
E. De Beck, L. Decin, A. de Koter +4
We aim to (1) set up simple and general analytical expressions to estimate mass-loss rates of evolved stars, and (2) from those calculate estimates for the mass-loss rates of asymp…
Herschel/HIFI deepens the circumstellar NH3 enigma
K. M. Menten, F. Wyrowski, J. Alcolea +23
Circumstellar envelopes (CSEs) of a variety of evolved stars have been found to contain ammonia (NH3) in amounts that exceed predictions from conventional chemical models by many o…
Herschel/HIFI observations of high-J CO transitions in the protoplanetary nebula CRL618
V. Bujarrabal, J. Alcolea, R. Soria-Ruiz +25
We performed Herschel/HIFI observations of several CO lines in the far-infrared/sub-mm in the protoplanetary nebula CRL618. The high spectral resolution provided by HIFI allows mea…
Discovery of water vapour in the carbon star V Cygni from observations with Herschel/HIFI
D. A. Neufeld, E. González-Alfonso, G. Melnick +25
We report the discovery of water vapour toward the carbon star V Cygni. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1(11) - 0(00) para-water t…
Water content and wind acceleration in the envelope around the oxygen-rich AGB star IK Tau as seen by Herschel/HIFI
L. Decin, K. Justtanont, E. De Beck +4
During their asymptotic giant branch, evolution low-mass stars lose a significant fraction of their mass through an intense wind, enriching the interstellar medium with products of…