相关论文: Modeling of the high-velocity jet powered by the m…
Jets and disk winds arise from materials with excess angular momentum ejected from the accretion disks in forming stars. How these structures are launched and how they impact the gas within the innermost regions of these objects remains…
MWC 349A is one of the rare stars known to have hydrogen radio recombination line (RRL) masers. The bright maser emission makes it possible to study the dynamics of the system at milli-arcsecond (mas) precision. We present Atacama Large…
Context. The best example of a massive star with an ionized outflow launched from its photoevaporating disk is MWC349A. The large amount of reported radio-continuum and radio-recombination line observations toward this galactic UC-HII…
The UC-HII region of MWC 349A is the prototype of an ionized wind driven by a massive star surrounded by a disk. Recent high angular resolution observations of the millimeter recombination lines have shown that the disk rotates with a…
We used the Submillimeter Array to map the angular distribution of the H30$\alpha$ recombination line (231.9 GHz) in the circumstellar region of the peculiar star MWC349A. The resolution was $1\farcs2$, but because of high signal-to-noise…
The Submillimeter Array (SMA) has been used to image the emission from radio recombination lines of hydrogen at subarcsecond angular resolution from the young high-mass star MWC349A in the H26$\alpha$, H30$\alpha$, and H31$\alpha$…
Disk winds are thought to play a critical role in star birth. As winds extract excess angular momentum from accretion disks, matter in the disk can be transported inward to the star to fuel mass growth. However, the observational evidence…
Theories of massive star formation predict that massive protostars accrete gas through circumstellar disks. Although several cases have been found already thanks to high-angular resolution interferometry, it remains unknown the internal…
We present interferometric observations with the Atacama Large Millimeter Array (ALMA) of the free-free continuum and recombination line emission at 1 and 3mm of the "Red Square Nebula" surrounding the B[e]-type star MWC922. The unknown…
The Galactic emission-line object MWC 349A is one of the brightest radio stars in the sky. The central object is embedded in an almost edge-on oriented Keplerian rotating thick disc that seems to drive a rotating bipolar wind. The dense…
We present new sensitive, high angular resolution 1.3, 2, and 6 cm observations of the continuum emission from the peculiar emission-line star MWC 349A, made with the Very Large Array. This radio emission is believed to originate in an…
The age and evolutionary status of MWC349A, the unique emission line star with maser and laser radiation in hydrogen recombination lines, remain unknown because the spectrum of the star is veiled by bright emission from the ionized disk and…
We report the discovery of a bipolar nebula around the peculiar emission-line star MWC 349A using archival Spitzer Space Telescope 24 um data. The nebula extends over several arcminutes (up to 5 pc) and has the same orientation and geometry…
We present the first detection of the H40a, H34a and H31a radio recombination lines (RRLs) at millimeter wavelengths toward the high-velocity, ionized jet in the Cepheus A HW2 star forming region. From our single-dish and interferometric…
We present ALMA archival data for 219-235 GHz continuum and line observations toward the hot molecular core (HMC) W49N MCN-a (UCHII region J1) at a resolution of ~0."3. The dust continuum emission, showing an elongated structure of…
Studying young, high-mass stellar objects is challenging for testing models of massive star formation due to their great distances, often kiloparsecs away. This requires extremely high-angular resolution to resolve features like accretion…
We report the detection, made using ALMA, of the 92 GHz continuum and hydrogen recombination lines (HRLs) H40$\alpha$, H42$\alpha$, and H50$\beta$ emission toward the ionized wind associated with the high-mass young stellar object…
Massive star formation involves significant ionization in the innermost regions near the central object, such as gravitationally trapped H II regions, jets, ionized disks, or winds. Resolved observations of the associated continuum and…
We present new spatially resolved observations of MWC 349A from the Large Binocular Telescope Interferometer (LBTI), a 23-meter baseline interferometer made up of two, co-mounted 8-meter telescopes. MWC 349A is a B[e] star with an unknown…
We present a detailed analysis of the spatially and spectrally resolved 12CO J=2-1 and J=3-2 emission lines from the TW Hya circumstellar disk, based on science verification data from the Atacama Large Millimeter/Submillimeter Array (ALMA).…