568 citations · 21.9k across the 202 of their papers we have counts for
10 papers · 2 filters
Effects of Magnetic Field Strength and Orientation on Molecular Cloud Formation
F. Heitsch, J. M. Stone, L. W. Hartmann
We present a set of numerical simulations addressing the effects of magnetic field strength and orientation on the flow-driven formation of molecular clouds. Fields perpendicular t…
Non-steady Accretion in Protostars
Zhaohuan Zhu, Lee Hartmann, Charles Gammie
Observations indicate that mass accretion rates onto low-mass protostars are generally lower than the rates of infall to their disks; this suggests that much of the protostellar ma…
Rapid Molecular Cloud and Star Formation: Mechanisms and Movies
Fabian Heitsch, Lee Hartmann
We demonstrate that the observationally inferred rapid onset of star formation after parental molecular clouds have assembled can be achieved by flow-driven cloud formation of atom…
Long-wavelength excesses of FU Orionis objects: flared outer disks or infalling envelopes?
Zhaohuan Zhu, Lee Hartmann, Nuria Calvet +3
The mid- to far-infrared emission of the outbursting FU Orionis objects has been attributed either to a flared outer disk or to an infalling envelope. We revisit this issue using d…
A Spitzer view of protoplanetary disks in the gamma Velorum cluster
Jesus Hernandez, Lee Hartmann, Nuria Calvet +4
We present new Spitzer Space Telescope observations of stars in the young ~5 Myr gamma Velorum stellar cluster. Combining optical and 2MASS photometry, we have selected 579 stars a…
Fragmentation of Shocked Flows: Gravity, Turbulence and Cooling
F. Heitsch, L. Hartmann, A. Burkert +1
The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitat…
A large-scale optical-near infrared survey for brown dwarfs and very low-mass stars in the Orion OB1 association
Juan José Downes, César Briceño, Jesús Hernández +3
We report the initial results of a large-scale optical-near infrared survey to extend the known young population of the entire Orion star-forming region down to the substellar doma…
The Disk Population of the Chamaeleon I Star-Forming Region
K. L. Luhman, L. E. Allen, P. R. Allen +6
We present a census of circumstellar disks in the Chamaeleon I star-forming region. Using the Infrared Array Camera and the Multiband Imaging Photometer onboard the Spitzer Space T…
Constraining the Envelope Structure of L1527 IRS: Infrared Scattered Light Modeling
John J. Tobin, Lee Hartmann, Nuria Calvet +1
We model Spitzer Space Telescope observations of the Taurus Class 0 protostar L1527 IRS (IRAS 04368+2557) to provide constraints on its protostellar envelope structure. The nearly…
Spitzer IRS Observations of Disks around Brown Dwarfs in the TW Hydra Association
A. L. Morrow, K. L. Luhman, C. Espaillat +8
Using SpeX at the NASA Infrared Telescope Facility and the Spitzer Infrared Spectrograph, we have obtained infrared spectra from 0.7 to 30um for three young brown dwarfs in the TW…