Related papers: The Angular Momentum Content and Evolution of Clas…
We present near-infrared K-band spectra for a sample of 7 Class 0 protostars in the Perseus and Orion star-forming regions. We detect Br gamma, CO overtone, and H2 emission, features that probe the near circumstellar environment of the…
We present the results of a detailed kinematic analysis of a significant fraction of the known population of Galactic star clusters aimed at constraining the physical mechanisms driving the onset and evolution of cluster rotation. Our study…
We investigate the rotational equilibrium state of a disk accreting magnetized stars using axisymmetric magnetohydrodynamic (MHD) simulations. In this ``locked'' state, the spin-up torque balances the spin-down torque so that the net…
Stars lose a significant amount of angular momentum between birth and death, implying that efficient processes transporting it from the core to the surface are active. Space asteroseismology delivered the interior rotation rates of more…
We present new models for the rotational evolution of solar-like stars between 1 Myr and 10 Gyr with the aim to reproduce the distributions of rotational periods observed for star forming regions and young open clusters within this age…
The main instabilities induced by rotation in stellar interiors are described. We derive from first principles the general equation describing the transport of the angular momentum. The case of the transport of the chemical species is also…
In the context of future space-based asteroseismic missions, we have studied the problem of extracting the rotation speed and the rotation-axis inclination of solar-like stars from the expected data. We have focused on slow rotators (at…
Angular momentum distribution and its redistribution are of crucial importance in formation and evolution of circumstellar disks. Many molecular line observations toward young stellar objects indicate that radial distributions of the…
Since the external regions of the envelopes of rapidly rotating early-type stars are unstable to convection, a coupling may exist between the convection and the internal rotation. We explore what can be learned from spectroscopic and…
Core rotation rates have been measured for red giant stars using asteroseismology. This data, along with helioseismic measurements and open cluster spin down studies, provide powerful clues about the nature and timescale for internal…
We present Atacama Large Millimeter/submillimeter Array observations of the $\sim$10 kAU environment surrounding 21 protostars in the Orion A molecular cloud tracing outflows. Our sample is composed of Class 0 to flat-spectrum protostars,…
Motivated by the recent detection of a large number of embedded young stellar objects (YSOs) with mass accretion rates that are inconsistent with the predictions of the standard model of inside-out collapse (Shu 1977), we perform a series…
We present projected rotational velocities for 20 early-type (B8-A9) and 74 late-type (F2-M8) members of the ~5 Myr old Upper Scorpius OB Association derived from high dispersion optical spectra obtained with the High Resolution Echelle…
We probe the geometry of magnetospheric accretion in classical T Tauri stars by modeling red absorption at He I 10830 via scattering of the stellar and veiling continua. Under the assumptions that the accretion flow is an azimuthally…
We report the results of a survey of low mass Class I protostars in the cm continuum. In the initial survey, seven sources in the Taurus star formation were observed with the VLA at 0``.25 resolution. All seven sources drive CO outflows and…
Magnetospheric accretion is a key process that shapes the inner disks of T Tauri stars, controlling mass and angular momentum evolution. It produces strong ultraviolet and optical emission that irradiates the planet-forming environment. In…
For early-type galaxies, the ability to sustain a corona of hot, X-ray emitting gas could have played a key role in quenching their star-formation history. Yet, it is still unclear what drives the precise amount of hot gas around these…
High-resolution spectroscopic measurements of blue horizontal-branch stars in six metal-poor globular clusters -- M3, M13, M15, M68, M92, and NGC 288 -- reveal remarkable variations in photospheric composition and rotation velocity as a…
We present the results of an interferometric study of the N2H+(1--0) emission from nine nearby, isolated, low-mass protostellar cores, using the OVRO millimeter array. The main goal of this study is the kinematic characterization of the…
We present solutions for the accretion disks and boundary layers in pre-main-sequence stars undergoing FU Orionis outbursts. These solutions differ from earlier disk solutions in that they include a self-consistent treatment of the boundary…