Results for "A. Belloche"

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Observation of rotation in star forming regions: clouds, cores, disks, and jetsMay 03 2013Angular momentum plays a crucial role in the formation of stars and planets. It has long been noticed that parcels of gas in molecular clouds need to reduce their specific angular momentum by 6 to 7 orders of magnitude to participate in the building of ... More
First results from the CALYPSO IRAM-PdBI survey - III. Monopolar jets driven by a proto-binary system in NGC1333-IRAS2AJan 26 2014Context: The earliest evolutionary stages of low-mass protostars are characterised by hot and fast jets which remove angular momentum from the circumstellar disk, thus allowing mass accretion onto the central object. However, the launch mechanism is still ... More
Disappearance of N2H+ from the Gas Phase in the Class 0 Protostar IRAM 04191Feb 01 2004We present a high-resolution spectroscopic study of the envelope of the young Class 0 protostar IRAM 04191+1522 in Taurus. N2H+(1-0) observations with the Plateau de Bure Interferometer and the IRAM 30m telescope demonstrate that the molecular ion N2H+ ... More
Re-exploring Molecular Complexity with ALMA (ReMoCA): Interstellar detection of ureaJun 11 2019Jun 17 2019Urea, NH2C(O)NH2, is a molecule of great importance in organic chemistry and biology. Two searches for urea in the interstellar medium were reported in the past, but neither were conclusive. We want to take advantage of the increased sensitivity and angular ... More
Probing the formation of intermediate- to high-mass stars in protoclusters: A detailed millimeter study of the NGC 2264 clumpsAug 29 2005We present the results of dust continuum and molecular line observations of two massive cluster-forming clumps, NGC 2264-C and NGC 2264-D, including extensive mapping performed with the MAMBO bolometer array and the HERA heterodyne array on the IRAM 30m ... More
Strongly induced collapse in the Class 0 protostar NGC 1333 IRAS 4AFeb 22 2006The onset of gravitational collapse in cluster-forming clouds is still poorly known. Our goal is to use the Class 0 protostar IRAS 4A, which is undergoing collapse in the active molecular cloud NGC 1333, to set constraints on this process. In particular ... More
Deuterium Fractionation in the Ophiuchus Molecular CloudDec 09 2015Aims. We measure the deuterium fraction, RD, and the CO-depletion factor, fd, toward a number of starless and protostellar cores in the L1688 region of the Ophiuchus molecular cloud complex and search for variations based upon environmental differences ... More
Strongly triggered collapse model confront observationsJan 24 2007Detailed modelling of individual protostellar condensations, is important to test the various theories. Here we present comparisons between strongly induced collapse models with one young class-0, IRAS4A in the Perseus cloud and one prestellar cloud observed ... More
The dynamical state of the First Hydrostatic Core Candidate Cha-MMS1Jun 27 2013Observations of First Hydrostatic Core candidates, a theoretically predicted evolutionary link between the prestellar and protostellar phases, are vital for probing the earliest phases of star formation. We aim to determine the dynamical state of the ... More
APEX telescope observations of new molecular ionsFeb 14 2011Hydrides are key ingredients of interstellar chemistry since they are the initial products of chemical networks that lead to the formation of more complex molecules. The fundamental rotational transitions of light hydrides fall into the submillimeter ... More
The dynamical influence of cooling in the envelope of prestellar and protostellar coresAug 05 2005We compute numerical simulations of spherical collapse triggered by a slow increase in external pressure. We compare isothermal models to models including cooling with a simple but self-consistent treatment of the coupling between gas, grains and radiation ... More
Molecular line study of the very young protostar IRAM 04191 in Taurus: Infall, rotation, and outflowJul 12 2002We present a detailed millimeter line study of the circumstellar environment of the low-luminosity Class 0 protostar IRAM 04191+1522 in the Taurus molecular cloud. New line observations demonstrate that the ~14000 AU radius protostellar envelope is undergoing ... More
The initial conditions of star formation in the Ophiuchus main cloud: Kinematics of the protocluster condensationsJun 11 2007Aug 02 2007The earliest phases of clustered star formation and the origin of the stellar initial mass function (IMF) are currently much debated. In order to constrain the origin of the IMF, we investigated the internal and relative motions of starless condensations ... More
First interstellar detection of OH+Apr 15 2010May 27 2010The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected in absorption ... More
Molecular complexity in the interstellar mediumJul 18 2019The search for complex organic molecules in the interstellar medium (ISM) has revealed species of ever greater complexity. This search relies on the progress made in the laboratory to characterize their rotational spectra. Our understanding of the processes ... More
A multi-transition submillimeter water maser study of evolved stars - detection of a new line near 475 GHzOct 27 2007Context: Maser emission from the H2O molecule probes the warm, inner circumstellar envelopes of oxygen-rich red giant and supergiant stars. Multi-maser transition studies can be used to put constraints on the density and temperature of the emission regions. ... More
Organic molecules, ions, and rare isotopologues in the remnant of the stellar-merger candidate, CK Vulpeculae (Nova 1670)Aug 07 2017Aug 18 2017CK Vul is a star whose outburst was observed in 1670-72. A stellar-merger event was proposed to explain its ancient eruption. Aims: We aim to investigate the composition of the molecular gas recently discovered in the remnant of CK Vul. Methods: We observed ... More
Complex organic molecules in diffuse clouds along the line of sight to Sgr B2Aug 24 2017Up to now, mostly relatively simple molecules have been detected in interstellar diffuse molecular clouds in our galaxy, but more complex species have been reported in the diffuse/translucent medium of a z = 0.89 spiral galaxy. We aim at searching for ... More
Will the starless cores in Chamaeleon I and III turn prestellar?Jun 24 2011The nearby Chamaeleon molecular cloud complex is a good laboratory to study the process of low-mass star formation since it consists of three clouds with very different properties. Cha III does not show any sign of star formation, while star formation ... More
Extended emission of D2H+ in a prestellar coreSep 14 2010Context: In the last years, the H2D+ and D2H+ molecules have gained great attention as probes of cold and depleted dense molecular cloud cores. These ions are at the basis of molecular deuterium fractionation, a common characteristic observed in star ... More
Star formation in Chamaeleon I and III: a molecular line study of the starless core populationNov 13 2014The Chamaeleon clouds are excellent targets for low-mass star formation studies. Cha I and II are actively forming stars while Cha III shows no sign of ongoing star formation. We aim to determine the driving factors that have led to the very different ... More
Exploring Molecular Complexity with ALMA (EMoCA): Deuterated complex organic molecules in Sagittarius B2(N2)Nov 18 2015Deuteration is a powerful tracer of the history of the cold prestellar phase in star forming regions. Apart from methanol, little is known about deuterium fractionation of complex organic molecules in the interstellar medium, especially in high mass star ... More
The search for complex molecules in the ISM: a complete 3 mm line survey of Sgr B2-N and -MJan 21 2008Famous for the extraordinary richness of its molecular content, the Sgr B2 molecular cloud complex is the prime target in the long-standing search for ever more complex species. We have completed a molecular line survey of the hot dense cores Sgr B2(N) ... More
Detection of 6.7 GHz methanol absorption towards hot corinosAug 14 2008Methanol masers at 6.7 GHz have been found exclusively towards high-mass star forming regions. Recently, some Class 0 protostars have been found to display conditions similar to what are found in hot cores that are associated with massive star formation. ... More
Submillimeter absorption from SH+, a new widespread interstellar radical, 13CH+ and HClSep 15 2010We have used the Atacama Pathfinder Experiment 12 m telescope (APEX) to carry out an absorption study of submillimeter wavelength rotational ground-state lines of H35Cl, H37Cl, 13CH+, and, for the first time, of the SH+ radical (sulfoniumylidene or sulfanylium). ... More
Interstellar HOCN in the Galactic center regionMay 14 2010Aims. Our aim is to confirm the interstellar detection of cyanic acid, HOCN, in the Galactic center clouds. It has previously been tentatively detected only in Sgr B2(OH). Methods. We used a complete line survey of the hot cores Sgr B2(N) and (M) in the ... More
Increased complexity in interstellar chemistry: Detection and chemical modeling of ethyl formate and n-propyl cyanide in Sgr B2(N)Feb 26 2009In recent years, organic molecules of increasing complexity have been found toward the prolific Galactic center source Sagittarius B2. We wish to explore the degree of complexity that the interstellar chemistry can reach in star-forming regions. We carried ... More
CO and CH3OH observations of the BHR71 outflows with APEXMay 16 2006Context : Highly-collimated outflows are believed to be the earliest stage in outflow evolution, so their study is essential for understanding the processes driving outflows. The BHR71 Bok globule is known to harbour such a highly-collimated outflow, ... More
Exploring molecular complexity with ALMA (EMoCA): Detection of three new hot cores in Sagittarius B2(N)Mar 28 2017The SgrB2 molecular cloud contains several sites forming high-mass stars. SgrB2(N) is one of its main centers of activity. It hosts several compact and UCHII regions, as well as two known hot molecular cores (SgrB2(N1) and SgrB2(N2)), where complex organic ... More
Outflow forces in intermediate mass star formationJul 07 2015Jul 10 2015Intermediate mass protostarsprovide a bridge between theories of low- and high-mass star formation. Emerging molecular outflows can be used to determine the influence of fragmentation and multiplicity on protostellar evolution through the correlation ... More
Toward understanding the formation of multiple systems - A pilot IRAM-PdBI survey of Class 0 objectsJan 20 2010The formation process of binary stars and multiple systems is poorly understood. Here, we seek to determine the typical outcome of protostellar collapse and to constrain models of binary formation by core fragmentation during collapse, using high-resolution ... More
Warm molecular gas and kinematics in the disc around HD 100546May 06 2010The disc around the Herbig Ae/Be star HD 100546 is one of the most extensively studied discs in the southern sky. Although there is a wealth of information about its dust content and composition, not much is known about its gas and large scale kinematics. ... More
The quest for complex molecules in space: Laboratory spectroscopy of n-butyl cyanide, n-C4H9CN, in the millimeter wave region and its astronomical search in Sagittarius B2(N)Apr 12 2012The saturated n-propyl cyanide was recently detected in Sagittarius B2(N). The next larger unbranched alkyl cyanide is n-butyl cyanide. We provide accurate rest frequency predictions beyond the millimeter wave range to search for this molecule in the ... More
Disappearance of N2H+ from the Gas Phase in the Class 0 Protostar IRAM 04191Apr 15 2004We present a high-resolution millimeter study of the very young Class 0 protostar IRAM 04191+1522 in the Taurus molecular cloud. N2H+(1-0) observations with the IRAM Plateau de Bure Interferometer and 30m telescope demonstrate that the molecular ion N2H+ ... More
The evolutionary state of the southern dense core Cha-MMS1May 18 2006Aims: Our goal is to set constraints on the evolutionary state of the dense core Cha-MMS1 in the Chamaeleon I molecular cloud. Methods: We analyze molecular line observations carried out with the new submillimeter telescope APEX. We look for outflow signatures ... More
First results from the CALYPSO IRAM-PdBI survey. II. Resolving the hot corino in the Class 0 protostar NGC 1333-IRAS2AJan 27 2014We investigate the origin of complex organic molecules (COMs) in the gas phase around the low-mass Class~0 protostar NGC1333-IRAS2A, to determine if the COM emission lines trace an embedded disk, shocks from the protostellar jet, or the warm inner parts ... More
First results from the CALYPSO IRAM-PdBI survey. I. Kinematics of the inner envelope of NGC1333-IRAS2AJan 27 2014Jan 31 2014The structure and kinematics of Class 0 protostars on scales of a few hundred AU is poorly known. Recent observations have revealed the presence of Keplerian disks with a diameter of 150-180 AU in L1527-IRS and VLA1623A, but it is not clear if such disks ... More
Extremely high velocity gas from the massive YSOs in IRAS 17233-3606Sep 02 2009Molecular outflows from high-mass young stellar objects provide an excellent way to study the star formation process, and investigate if they are scaled-up versions of their low-mass counterparts. We selected the nearby massive star forming region IRAS ... More
Spectroscopic study and astronomical detection of doubly 13C-substituted ethyl cyanideApr 12 2016We have performed a spectral line survey called EMoCA toward Sagittarius B2(N) between 84 and 114 GHz with ALMA. Line intensities of the main isotopic species of ethyl cyanide and its singly 13C-substituted isotopomers observed toward the hot molecular ... More
The Initial Conditions of Clustered Star Formation III. The Deuterium Fractionation of the Ophiuchus B2 CoreJun 23 2010We present N2D+ 3-2 (IRAM) and H2D+ 1_11 - 1_10 and N2H+ 4-3 (JCMT) maps of the small cluster-forming Ophiuchus B2 core in the nearby Ophiuchus molecular cloud. In conjunction with previously published N2H+ 1-0 observations, the N2D+ data reveal the deuterium ... More
The interaction of young massive stars with their environment: A millimeter and submillimeter line study of NGC6334 FIR IIFeb 25 2007Using the 15-m Swedish ESO Sub-millimeter Telescope (SEST), CO, HCN, and HCO+ observations of the galactic star-forming region NGC6334 FIR II are presented, complemented by [C I] 3^P_1--3^P_0 and 3^P_2--3^P_1 data from the Atacama Pathfinder Experiment ... More
Glycolaldehyde in Perseus young solar analogsJan 03 2017Aims: In this paper we focus on the occurrence of glycolaldehyde (HCOCH2OH) in young solar analogs by performing the first homogeneous and unbiased study of this molecule in the Class 0 protostars of the nearby Perseus star forming region. Methods: We ... More
The complex chemistry of hot cores in Sagittarius B2(N): Influence of cosmic-ray ionization and thermal historyJun 11 2019As the number of complex organic molecules (COMs) detected in the interstellar medium increases, it becomes important to place meaningful constraints on the formation pathways of these species. The molecular cloud SgrB2(N) is host to several hot molecular ... More
Re-exploring Molecular Complexity with ALMA (ReMoCA): Interstellar detection of ureaJun 11 2019Urea, NH2C(O)NH2, is a molecule of great importance in organic chemistry and biology. Two searches for urea in the interstellar medium were reported in the past, but neither were conclusive. We want to take advantage of the increased sensitivity and angular ... More
Detection of amino acetonitrile in Sgr B2(N)Jan 21 2008Mar 04 2008Amino acids are building blocks of proteins and therefore key ingredients for the origin of life. The simplest amino acid, glycine, has long been searched for in the interstellar medium but has not been unambiguously detected so far. Since the search ... More
Rotational spectroscopy, tentative interstellar detection, and chemical modelling of N-methylformamideJan 17 2017N-methylformamide, CH3NHCHO, may be an important molecule for interstellar pre-biotic chemistry because it contains a peptide bond. The rotational spectrum of the most stable trans conformer of CH3NHCHO is complicated by strong torsion-rotation interaction ... More
Probing the CO and methanol snow lines in young protostars. Results from the CALYPSO IRAM-PdBI surveyApr 18 2016Context. "Snow lines", marking regions where abundant volatiles freeze out onto the surface of dust grains, play an important role for planet growth and bulk composition in protoplanetary disks. They can already be observed in the envelopes of the much ... More
Spectral imaging of the Sagittarius B2 region in multiple 3-mm molecular lines with the Mopra telescopeDec 03 2007Jan 24 2008Using the Mopra telescope, we have undertaken a 3-mm spectral-line imaging survey of a 5 x 5 arcmin^2 area around Sgr B2. We covered almost the complete spectral the range from 81.7 to 113.5 GHz, with 2.2 MHz wide spectral channels or ~ 6 km/s, and have ... More
Exploring molecular complexity with ALMA (EMoCA): Alkanethiols and alkanols in Sagittarius B2(N2)Dec 16 2015Over the past five decades, radio astronomy has shown that molecular complexity is a natural outcome of interstellar chemistry, in particular in star forming regions. However, the pathways that lead to the formation of complex molecules are not completely ... More
The IRAM-30m line survey of the Horsehead PDR: II. First detection of the l-C3H+ hydrocarbon cationOct 30 2012We present the first detection of the l-C3H+ hydrocarbon in the interstellar medium. The Horsehead WHISPER project, a millimeter unbiased line survey at two positions, namely the photo-dissociation region (PDR) and the nearby shielded core, revealed a ... More
APEX mapping of H3O+ in the Sgr B2 regionMay 23 2006The cosmic-ray ionization rate (zeta) of dense molecular clouds is a key parameter for their dynamics and chemistry. Variations of zeta are well established, but it is unclear if these are related to source column density or to Galactic location. Using ... More
The end of star formation in Chamaeleon I ? A LABOCA census of starless and protostellar coresJan 04 2011Chamaeleon I is the most active region in terms of star formation in the Chamaeleon molecular cloud complex. Its population of prestellar and protostellar cores is not known and a controversy exists concerning its history of star formation. Our goal is ... More
Small-scale physical and chemical structure of diffuse and translucent molecular clouds along the line of sight to Sgr B2Jan 10 2019The diffuse and translucent molecular clouds traced in absorption along the line of sight to strong background sources have so far been investigated mainly in the spectral domain because of limited angular resolution or small sizes of the background sources. ... More
APECS - The Atacama Pathfinder Experiment Control SystemMay 04 2006APECS is the distributed control system of the new Atacama Pathfinder EXperiment (APEX) telescope located on the Llano de Chajnantor at an altitude of 5107 m in the Atacama desert in northern Chile. APECS is based on Atacama Large Millimeter Array (ALMA) ... More
Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546May 17 2016The composition of planetary solids and gases is largely rooted in the processing of volatile elements in protoplanetary disks. To shed light on the key processes, we carry out a comparative analysis of the gas-phase carbon abundance in two systems with ... More
Jet multiplicity in the proto-binary system NGC1333-IRAS4A. The detailed CALYPSO IRAM-PdBI viewNov 04 2015Owing to the paucity of sub-arcsecond (sub)mm observations required to probe the innermost regions of newly forming protostars, several fundamental questions are still being debated, such as the existence and coevality of close multiple systems. We study ... More
APEX-CHAMP+ high-J CO observations of low-mass young stellar objects: III. NGC 1333 IRAS 4A/4B envelope, outflow and UV heatingMar 13 2012NGC 1333 IRAS 4A and IRAS 4B sources are among the best studied Stage 0 low-mass protostars which are driving prominent bipolar outflows. Most studies have so far concentrated on the colder parts (T<30K) of these regions. The aim is to characterize the ... More
Detection of OD towards the low-mass protostar IRAS16293-2422Mar 13 2012Although water is an essential and widespread molecule in star-forming regions, its chemical formation pathways are still not very well constrained. Observing the level of deuterium fractionation of OH, a radical involved in the water chemical network, ... More
Chronology of Episodic Accretion in Protostars -- an ALMA survey of the CO and H$_2$O snowlinesSep 06 2019Episodic accretion has been used to explain the wide range of protostellar luminosities, but its origin and influence on the star forming process are not yet fully understood. We present an ALMA survey of N$_2$H$^+$ ($1-0$) and HCO$^+$ ($3-2$) toward ... More
Characterizing young protostellar disks with the CALYPSO IRAM-PdBI survey: large Class 0 disks are rareOct 26 2018Nov 12 2018Understanding the formation mechanisms of protoplanetary disks and multiple systems, and their pristine properties, is a key question for modern astrophysics. The properties of the youngest disks, embedded in rotating infalling protostellar envelopes, ... More
The search for high-mass protostars with ALMA revealed up to kilo-parsec scales (SPARKS): I. Indication for a centrifugal barrier in the environment of a single high-mass envelopeApr 17 2018The formation of the most massive O-type stars is poorly understood. We present a case study of a young massive clump from the ATLASGAL survey, G328.2551-0.5321. It exhibits a bolometric luminosity of 1.3$\times$10$^4$ L$_{\odot}$ corresponding to a current ... More
Probable detection of H2D+ in the starless core Barnard 68May 22 2006The presence of H2D+ in dense cloud cores underlies ion-molecule reactions that strongly enhance the deuterium fractionation of many molecular species. We determine the H2D+ abundance in one starless core, Barnard 68, that has a particularly well established ... More
Spectral imaging of the Central Molecular Zone in multiple 3-mm molecular linesOct 07 2011We have mapped 20 molecular lines in the Central Molecular Zone (CMZ) around the Galactic Centre, emitting from 85.3 to 93.3 GHz. This work used the 22-m Mopra radio telescope in Australia, equipped with the 8-GHz bandwidth UNSW-MOPS digital filter bank, ... More
First image of the L1157 molecular jet by the CALYPSO IRAM-PdBI surveyAug 17 2016Fast jets are thought to be a crucial ingredient of star formation because they might extract angular momentum from the disk and thus allow mass accretion onto the star. However, it is unclear whether jets are ubiquitous, and likewise, their contribution ... More
Rotational spectroscopy of isotopic species of methyl mercaptan at millimeter and submillimeter wavelengths: CH$_3$$^{34}$SHJun 03 2019Methyl mercaptan (CH$_3$SH) is an important sulfur-bearing species in the interstellar medium, terrestrial environment, and potentially in planetary atmospheres. The aim of the present study is to provide accurate spectroscopic parameters for the most ... More
An ATCA Survey of Sagittarius~B2 at 7~mm: Chemical Complexity Meets Broadband InterferometryAug 10 2015We present a 30 - 50 GHz survey of Sagittarius B2(N) conducted with the Australia Telescope Compact Array (ATCA) with 5 - 10 arcsec resolution. This work releases the survey data and demonstrates the utility of scripts that perform automated spectral ... More
Detailed Studies of Cloud Cores: Probing the Initial Conditions for Protostellar CollapseDec 15 2003Improving our understanding of the earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We discuss recent advances made in this area thanks to detailed mapping observations ... More
Submillimeter Studies of Prestellar Cores and Protostars: Probing the Initial Conditions for Protostellar CollapseDec 20 2002Improving our understanding of the initial conditions and earliest stages of protostellar collapse is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. Observationally, there are two complementary approaches ... More
Widening of Protostellar Outflows: an Infrared Outflow Survey in Low Luminosity ObjectsFeb 09 2017We present an outflow survey toward 20 Low Luminosity Objects (LLOs), namely protostars with an internal luminosity lower than 0.2 Lsun. Although a number of studies have reported the properties of individual LLOs, the reasons for their low luminosity ... More
IRAS 16253-2429: the First Proto-Brown Dwarf Binary Candidate Identified through Dynamics of JetsMay 10 2016The formation mechanism of brown dwarfs (BDs) is one of the long-standing problems in star formation because the typical Jeans mass in molecular clouds is too large to form these substellar objects. To answer this question, it is crucial to study a BD ... More
A 500 pc filamentary gas wisp in the disk of the Milky WayOct 11 2013Star formation occurs in molecular gas. In previous studies, the structure of the molecular gas has been studied in terms of molecular clouds, but has been overlooked beyond the cloud scale. We present an observational study of the molecular gas at 49.5 ... More
APEX-CHAMP+ high-J CO observations of low-mass young stellar objects: IV. Mechanical and radiative feedbackJan 14 2015During the embedded stage of star formation, bipolar molecular outflows and UV radiation from the protostar are important feedback processes. Our aim is to quantify the feedback, mechanical and radiative, for a large sample of low-mass sources. The outflow ... More
ALMA observations of the protostellar disk around the VeLLO IRAS 16253-2429Nov 28 2018We present ALMA long-baseline observations toward the Class 0 protostar IRAS 16253-2429 (hereafter IRAS 16253) with a resolution down to 0.12" (~15 au). The 1.3 mm dust continuum emission has a deconvolved Gaussian size of 0.16" x 0. 07" (20 au x 8.8 ... More
Observations of the Goldreich-Kylafis effect in star-forming regions with XPOL at the IRAM 30m telescopeOct 16 2008The Goldreich-Kylafis (GK) effect causes certain molecular line emission to be weakly linearly polarized, e.g., in the presence of a magnetic field. Compared to polarized dust emission, the GK effect has the potential to yield additional information along ... More
Complex organic molecules in the interstellar medium: IRAM 30 m line survey of Sagittarius B2(N) and (M)Aug 23 2013The discovery of amino acids in meteorites and the detection of glycine in samples returned from a comet to Earth suggest that the interstellar chemistry is capable of producing such complex organic molecules. Our goal is to investigate the degree of ... More
Microphysics and dynamics of the Gamma-Ray Burst 121024AMar 25 2015May 02 2016Aims. The aim of the study is to constrain the physics of gamma-ray bursts (GRBs) by analysing the multi-wavelength afterglow data set of GRB 121024A that covers the full range from radio to X-rays. Methods. Using multi-epoch broad-band observations of ... More
Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanideOct 09 2014The largest non-cyclic molecules detected in the interstellar medium (ISM) are organic with a straight-chain carbon backbone. We report an interstellar detection of a branched alkyl molecule, iso-propyl cyanide (i-C3H7CN), with an abundance 0.4 times ... More
Rotational spectroscopy of isotopic vinyl cyanide, H$_2$C=CH$-$C$\equiv$N, in the laboratory and in spaceJun 12 2008The rotational spectra of singly substituted $^{13}$C and $^{15}$N isotopic species of vinyl cyanide have been studied in natural abundances between 64 and 351 GHz. In combination with previous results, greatly improved spectroscopic parameters have been ... More
Hot HCN around young massive stars at 0.1" resolutionMar 10 2011Mar 24 2011Massive stars form deeply embedded in dense molecular gas, which they stir and heat up and ionize. During an early phase, the ionization is confined to hypercompact HII regions, and the stellar radiation is entirely absorbed by dust, giving rise to a ... More
Properties of the Molecular Cores of Low Luminosity ObjectsFeb 23 2015We present a survey toward 16 Low Luminosity Objects (LLOs with an internal luminosity, Lint, lower than 0.2 Lsun) with N2H+ (1-0), N2H+ (3-2), N2D+ (3-2), HCO+ (3-2) and HCN (3-2) using the Arizona Radio Observatory Kitt Peak 12m Telescope and Submillimeter ... More
Initial conditions for star formation in clusters: physical and kinematical structure of the starless core Oph A-N6Nov 18 2011We present high spatial (<300 AU) and spectral (0.07 km/s) resolution Submillimeter Array observations of the dense starless cluster core Oph A-N6, in the 1 mm dust continuum and the 3-2 line of N2H+ and N2D+. The dust continuum observations reveal a ... More
Probing Episodic Accretion in Very Low Luminosity ObjectsJan 14 2018Episodic accretion has been proposed as a solution to the long-standing luminosity problem in star formation; however, the process remains poorly understood. We present observations of line emission from N2H+ and CO isotopologues using the Atacama Large ... More
Herschel observations of deuterated water towards Sgr B2(M)Jul 29 2010Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes -- grain surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions ... More
CALYPSO view of SVS 13A with PdBI: Multiple jet sourcesJul 07 2017Aims. We wish to clarify the origin of the multiple jet features emanating from the binary protostar SVS 13A (= VLA4A/VLA4B). Methods. We used the Plateau de Bure Interferometer to map at 0.3-0.8" (~70-190 au) dust emission at 1.4 mm, CO(2-1), SiO(5-4), ... More
Laboratory spectroscopic study and astronomical detection of vibrationally excited n-propyl cyanideAug 29 2016We performed a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius~B2(N) between 84.1 and 114.4 GHz with the Atacama Large Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. We determined line intensities ... More
Laboratory rotational spectroscopy of isotopic acetone, CH$_3^{13}$C(O)CH$_3$ and $^{13}$CH$_3$C(O)CH$_3$, and astronomical search in Sagittarius B2(N2)Jul 18 2019We want to study the rotational spectra of CH$_3^{13}$C(O)CH$_3$ and $^{13}$CH$_3$C(O)CH$_3$ and search for them in Sagittarius B2(N2). We investigated the laboratory rotational spectrum of isotopically enriched CH$_3^{13}$C(O)CH$_3$ between 40 GHz and ... More
Dimethyl ether in its ground state, v=0, and lowest two torsionally excited states, v11=1 and v15=1, in the high-mass star-forming region G327.3-0.6Feb 25 2013The goal of this paper is to determine the respective importance of solid state vs. gas phase reactions for the formation of dimethyl ether. This is done by a detailed analysis of the excitation properties of the ground state and the torsionally excited ... More
Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C$_2$H$_3$SHFeb 15 2019We have extended the pure rotational investigation of the two isomers syn and anti vinyl mercaptan to the millimeter domain using a frequency-multiplication spectrometer. The species were produced by a radiofrequency discharge in 1,2-ethanedithiol. Additional ... More
Rotational and high-resolution infrared spectrum of HC$_3$N: global ro-vibrational analysis and improved line catalogue for astrophysical observationsNov 23 2017HC$_3$N is an ubiquitous molecule in interstellar environments, from external galaxies, to Galactic interstellar clouds, star forming regions, and planetary atmospheres. Observations of its rotational and vibrational transitions provide important information ... More
Herschel observations of extra-ordinary sources: Detecting spiral arm clouds by CH absorption linesJul 12 2010We have observed CH absorption lines ($J=3/2, N=1 \leftarrow J=1/2, N=1$) against the continuum source Sgr~B2(M) using the \textit{Herschel}/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31 CH absorption ... More
Quantum-Limited Amplification via Reservoir EngineeringNov 01 2013Apr 08 2014We describe a new kind of phase-preserving quantum amplifier which utilizes dissipative interactions in a parametrically-coupled three-mode bosonic system. The use of dissipative interactions provides a fundamental advantage over standard cavity-based ... More
Crossed Andreev reflection in diffusive contactsNov 06 2006Crossed Andreev reflection in multiterminal structures in the diffusive regime is addressed within the quasiclassical Keldysh-Usadel formalism. The elastic cotunneling and crossed Andreev reflection of quasiparticles give nonlocal currents and voltages ... More
Quantum corrections to energy of short spinning string in AdS5Jun 29 2008Feb 02 2009Motivated by desire to shed light on the strong coupling behaviour of anomalous dimensions of "short" gauge theory operators we consider the famous example of folded spinning string in AdS_5 in the limit of small semiclassical spin parameter \S = S/sqrt[lambda]. ... More
A statistical model of three-dimensional anisotropy and intermittency in strong Alfvénic turbulenceMay 24 2016We propose a simple statistical model of three-dimensionally anisotropic, intermittent, strong Alfv\'enic turbulence, incorporating both critical balance and dynamic alignment. Our model is based on log-Poisson statistics for Elsasser-field increments ... More
One- and many-body effects on mirages in quantum corralsAug 27 2002May 23 2003Recent interesting experiments used scanning tunneling microscopy to study systems involving Kondo impurities in quantum corrals assembled on Cu or noble metal surfaces. The solution of the two-dimensional one-particle Schrodinger equation in a hard wall ... More
New results for the missing quantum numbers labeling the quadrupole and octupole boson basisMay 24 2004Oct 27 2004The many $2^k$-pole boson states, $|N_kv_k\alpha_k I_kM_k>$ with $k=2,3$, realize the irreducible representation (IR) for the group reduction chains $SU(2k+1)\supset R_{2k+1}\supset R_3\supset R_2$. They have been analytically studied and widely used ... More
Light composite scalar boson from a see-saw mechanism in two-scale TC modelsJun 25 2015We consider the possibility of a light composite scalar boson arising from mass mixing between a relatively light and heavy scalar singlets in a see-saw mechanism expected to occur in two-scale Technicolor (TC) models. A light composite scalar boson can ... More
Limit on the fermion masses in technicolor modelsAug 21 2003Recently it has been pointed out that no limits can be put on the scale of fermion mass generation $(M)$ in technicolor models, because the relation between the fermion masses $(m_f)$ and $M$ depends on the dimensionality of the interaction responsible ... More
Technicolor models with coupled systems of Schwinger-Dyson equationsFeb 28 2019Mar 15 2019When Technicolor (TC), QCD, Extended Technicolor (ETC) and other interactions become coupled through their different Schwinger-Dyson equations, the solution of these equations are modified in comparison with the ones of the isolated equations. The change ... More
Dynamical Symmetry Breaking in a Minimal 3-3-1 ModelOct 11 2012The gauge symmetry breaking in some versions of 3-3-1 models can be implemented dynamically because at the scale of a few TeVs the $U(1)_X$ coupling constant becomes strong. In this work we consider the dynamical symmetry breaking in a minimal $SU(3)_{{}_{TC}}\times ... More