A5019712147- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Molecular Spectroscopy and Structure
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Spacecraft and Cryogenic Technologies
- Gamma-ray bursts and supernovae
- Atomic and Subatomic Physics Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Molecular spectroscopy and chirality
- Laser-Plasma Interactions and Diagnostics
- Advanced X-ray Imaging Techniques
- Superconducting and THz Device Technology
- High-pressure geophysics and materials
- Planetary Science and Exploration
- Spectroscopy and Quantum Chemical Studies
- Plant Parasitism and Resistance
- Astronomical Observations and Instrumentation
- Various Chemistry Research Topics
- Laser-induced spectroscopy and plasma
- Advanced Combustion Engine Technologies
SKA Observatory
2024
Centre National de la Recherche Scientifique
2020-2024
Institut de Planétologie et d'Astrophysique de Grenoble
2022-2024
Université Grenoble Alpes
2020-2024
Institut de Radioastronomie Millimétrique
2018-2022
TD Bank
2019
University of Leeds
2015-2018
National Radio Astronomy Observatory
2016-2017
University of Nebraska–Lincoln
2012-2013
African Explosives (South Africa)
2002
We report the generation of MeV x rays using an undulator and accelerator that are both driven by same 100-terawatt laser system. The pulse driving scattering independently optimized to generate a high energy electron beam ($>200\text{ }\text{ }\mathrm{MeV}$) maximize output x-ray brightness. total photon number was measured be $\ensuremath{\sim}1\ifmmode\times\else\texttimes\fi{}{10}^{7}$, source size $5\text{ }\ensuremath{\mu}\mathrm{m}$, divergence angle $\ensuremath{\sim}10\text{...
Radio continuum observations using the Australia telescope compact array at 5.5, 9.0, 17.0 and 22.8 GHz have detected free–free emission associated with 45 of 49 massive young stellar objects H ii regions. Of these, 26 sources are classified as ionized jets (12 which candidates), 2 ambiguous or disc winds, 1 a disc-wind, 14 regions were unable to be categorized. Classification is based upon morphology, radio flux spectral index, in conjunction previous observational results other...
Context. In the past few years, there has been a rise in detection of streamers, asymmetric flows material directed toward protostellar disk with from outside star's natal core. It is unclear how they affect process mass accretion, particular beyond Class 0 phase. Aims. We investigate gas kinematics around Per-emb-50, I source crowded star-forming region NGC 1333. Our goal to study infall proceeds envelope scales this source. Results. discover streamer delivering Per-emb-50 H$_2$CO and...
The ALMA-IMF Large Program imaged a total noncontiguous area of 53pc2, covering 15 extreme, nearby protoclusters the Milky Way. They were selected to span relevant early protocluster evolutionary stages. Our 1.3mm and 3mm observations provide continuum images that are homogeneously sensitive point-like cores with masses 0.2 0.6Msun, respectively, matched spatial resolution 2000au. We also detect lines probe structure, kinematics, chemistry, feedback over scales from clouds filaments cores....
The ALMA-IMF Large Program observed the W43-MM2-MM3 ridge, whose 1.3mm and 3mm ALMA 12m array continuum images reach a 2500au spatial resolution. We used both best-sensitivity line-free images, reduced noise with multi-resolution segmentation technique MnGSeg, derived most complete robust core catalog possible. Using two different extraction software packages, getsf GExt2D, we identified 200 compact sources, 100 common sources have on average fluxes consistent to within 30%. filtered...
Among the most central open questions regarding initial mass function (IMF) of stars is impact environment on shape core (CMF) and thus potentially IMF. The ALMA-IMF Large Program aims to investigate variations in distributions with cloud characteristics, as diagnostic observables formation process evolution clouds. present study focuses W43-MM2&MM3 mini-starburst, whose CMF has recently been found be top-heavy respect Salpeter slope. harbors a rich cluster that contains statistically...
Context. The origin of the stellar initial mass function (IMF) and its relation with core (CMF) are actively debated issues important implications in astrophysics. Recent observations W43 molecular complex top-heavy CMFs, an excess high-mass cores compared to canonical distribution, raise questions about our understanding star formation processes their evolution space time. Aims. We aim compare populations protostellar prestellar three regions imaged ALMA-IMF Large Program. Methods. created...
Sites associated with high-mass star and cluster formation exhibit a so-called hot core phase, characterized by high temperatures column densities of complex organic molecules. We built comprehensive census candidates towards the ALMA-IMF protoclusters based on detection two CH3OCHO emission lines at 216.1 GHz. used source extraction algorithm GExt2D to identify peaks methyl formate (CH3OCHO) that is species commonly observed sites formation. up catalog 76 masses ranging from about 0.2 80...
Context. One of the central questions in astrophysics is origin initial mass function (IMF). It intrinsically linked to processes from which it originates, and hence its connection with core (CMF) must be elucidated. Aims. We aim measure CMF evolved W33-Main star-forming protocluster compare recently obtained other Galactic regions, including ones that are part ALMA-IMF program. Methods. used observations large programme: ~2′ × 2′ maps emission continuum selected lines at 1.3 mm 3 observed...
Correlations between the accretion luminosity and emission line luminosities (Lacc Lline) of pre-main-sequence (PMS) stars have been published for many different spectral lines, which are used to estimate rates. Despite origin those correlations is unknown, this could be attributed direct or indirect physical relations formation mechanism. This work shows that all (near-UV/optical/near-IR) Lacc–Lline result fact stellar (L*) correlated, not necessarily related with line. Synthetic...
ALMA-IMF is an Atacama Large Millimeter/submillimeter Array (ALMA) Program designed to measure the core mass function (CMF) of 15 protoclusters chosen span their early evolutionary stages. It further aims understand kinematics, chemistry, and impact gas inflow, accretion, dynamics on CMF. We present here first release line data cubes (DR1), produced from combination two ALMA 12m-array configurations. The include 12 spectral windows, with eight at 1.3mm four 3mm. broad coverage (~6.7 GHz...
Context . A crucial aspect in addressing the challenge of measuring core mass function (CMF), that is pivotal for comprehending origin initial (IMF), lies constraining temperatures cores. Aims We aim to measure luminosity, mass, column density and dust temperature star-forming regions imaged by ALMA-IMF large program. These fields were chosen encompass early evolutionary stages massive protoclusters. High angular resolution mapping required capture properties protostellar pre-stellar cores...
The stellar initial mass function (IMF) is critical to our understanding of star formation and the effects young stars on their environment. On large scales, it enables us use tracers such as UV or Hα emission estimate rate a system interpret unresolved clusters across Universe. So far, there little firm evidence large-scale variations IMF, which thus generally considered “universal”. Stars form from cores, now possible core masses compare (CMF) with presumably produces. goal ALMA-IMF...
The mass segregation of stellar clusters could be primordial rather than dynamical. Despite the abundance studies for clusters, those progenitors are still scarce, so question on origin and evolution is open. Our goal to characterize structure NGC 2264 molecular cloud compare populations clumps young objects (YSOs) in this region whose rich YSO population has shown evidence sequential star formation. We separated Herschel column density map three subregions compared their power spectra using...
Aims. We present high-sensitivity and high spectral-resolution NOEMA observations of the Class 0/I binary system SVS13A, composed low-mass protostars VLA4A VLA4B, with a separation ~90 au. is undergoing an accretion burst that enriching chemistry surrounding gas, which provides excellent opportunity to probe chemical physical conditions as well process. Methods. observe (12 K –11 ) lines CH 3 CN 13 CN, DCN (3–2) line, C 18 O (2–1) line toward SVS13A using NOEMA. Results. find complex...
Context . Electron fraction and cosmic-ray ionization rates in star-forming regions are important quantities astrochemical modeling critical to the degree of coupling between neutrals, ions, electrons, which regulates dynamics magnetic field. However, these difficult estimate. Aims We aim derive electron rate maps an active region. Methods combined observations nearby NGC 1333 region carried out with NOEMA interferometer IRAM 30 m single dish generate high spatial dynamic range different...
We present the first data release of ALMA-IMF Large Program, which covers 12m-array continuum calibration and imaging. The Program is a survey fifteen dense molecular cloud regions spanning range evolutionary stages that aims to measure core mass function (CMF). describe acquisition done by Atacama Millimeter/submillimeter Array (ALMA) observatory subsequent imaging we performed. image products are combinations multiple 12m array configurations created from selection observed bandwidth using...
Electron fraction and cosmic-ray ionization rates (CRIR) in star-forming regions are important quantities astrochemical modeling critical to the degree of coupling between neutrals, ions, electrons, which regulates dynamics magnetic field. However, these difficult estimate. We aim derive electron CRIR maps an active region. combined observations nearby NGC 1333 region carried out with NOEMA interferometer IRAM 30-m single dish generate high spatial dynamic range different molecular...
The Cygnus-X complex is a massive (a few $10^6$,M_⊙ molecular gas mass), nearby (1.4,kpc) star-forming region with several OB associations. Of these, Cyg OB2 the largest, at least 169 stars. DR18 largest globule near association, making it perfect target for investigating influence of ultraviolet radiation on clouds. By analyzing emission from different species, we aim to study structures toward using high angular-resolution line observations. As part Cygnus Allscale Survey Chemistry and...
The Cygnus-X complex is a massive, nearby (1.4 kpc) star-forming region with several OB associations. As part of the Cygnus Allscale Survey Chemistry and Dynamical Environments (CASCADE) program, we carried out 3.6 millimeter (mm) continuum spectral line high-resolution observations ($\sim$ 3 - 4$''$) toward DR18, covering molecular species Northern Extended Millimeter Array (NOEMA) Institut de Radioastronomie Millim\'etrique (IRAM) 30m telescope. In addition, multi-wavelength archival...
Quantifying the accretion flow from large cloud scales down to individual protostars is a central ingredient understanding of (high-mass) star formation. We characterize and quantify this multi-scale for prototypical high-mass star-forming region. In analysis parsec ∼50,au scales, we combined multiple single-dish interferometric observations study gas large-scale sizes several (Mopra) via intermediate-scale filamentary flows (ALMA-IMF) cores (ALMA DIHCA configuration 10 data). The...
High-mass prestellar cores are extremely rare. The search for such objects has long been hindered by small sample sizes, leading to large uncertainties in their lifetimes and the conditions which high-mass stars ($> 8\,M_{\odot}$) form. We leverage ($\sim 580$ cores) detected ALMA-IMF survey identify both protostellar estimate relative lifetimes. use CO SiO outflows introduce a new automated method based on aperture line emission background subtraction systematically detect associated with...
Aims: We characterize and quantify this multi-scale flow for a prototypical high-mass star-forming region. Methods: In analysis from parsec to ~50au scales, we combined multiple single-dish interferometric observations study the gas large-scale sizes of several (Mopra) via intermediate-scale filamentary flows (ALMA-IMF) central cores (ALMA DIHCA configuration 10 data). The highest-resolution multi-configuration ALMA dataset achieved spatial resolution 0.027''x0.022'' or 50au. Results: This...
High-mass prestellar cores are extremely rare. Until recently, the search for such objects has been hampered by small sample sizes, leading to large ambiguities in their lifetimes and hence conditions which high-mass stars (rm ≳ 8 ⊙ ) form. Here we leverage (∼,580 cores) detected ALMA-IMF survey identify both protostellar estimate relative lifetimes. We used CO SiO outflows cores. present a new automated method based on aperture line emission background subtraction systematically detect...