Zinnecker, Hans, Beuther, Henrik
This paper presents a summary of a panel discussion to more directly confront theoretical models and observational constraints in massive star formation research. The panel was moderated by Hans...
Deep Infrared Imaging of the R Corona Australis Cloud Core (2007)
Bruce A. Wilking, Mark J. Mccaughrean, Michael G. Burton, Timothy Giblin, John T. Rayner, Hans Zinnecker
Preliminary analysis is presented for J, H, and K 0 images of the Corona Australis cloud core. Color-color and color-magnitude diagrams reveal relatively few new cluster members. We conclude that the...
Thomas Stanke, Mark J. Mccaughrean, Hans Zinnecker
A&A manuscript no. (will be inserted by hand later) Your thesaurus codes are:
Disks around young stars with VLTI/MIDI (2007)
Van Boekel, Roy, Abraham, Peter, Correia, Serge, De Koter, Alex, Dominik, Carsten, Dutrey, Anne, ...
We report on observations of circumstellar disks around young stars that have been obtained with the MIDI instrument, which is mounted on the VLT Interferometer and operates in the 10 micrometer...
Toward Understanding Massive Star Formation (2007)
Zinnecker, Hans, Yorke, Harold W.
Although fundamental for astrophysics, the processes that produce massive stars are not well understood. Large distances, high extinction, and short timescales of critical evolutionary phases make...
Apai, Dániel, Bik, Arjan, Kaper, Lex, Henning, Thomas, Zinnecker, Hans
We present the first multiepoch radial velocity study of embedded young massive stars using near-infrared spectra obtained with ISAAC mounted at the ESO Very Large Telescope, with the aim of...
Sequentially Triggered Star Formation in OB Associations (2006)
Preibisch, Thomas, Zinnecker, Hans
We discuss observational evidence for sequential and triggered star formation in OB associations. We first review the star formation process in the Scorpius-Centaurus OB association, the nearest OB...
Apai, Daniel, Bik, Arjan, Kaper, Lex, Henning, Thomas, Zinnecker, Hans
We present the first multi-epoch radial velocity study of embedded young massive stars using near-infrared spectra obtained with ISAAC mounted at the ESO Very Large Telescope, with the aim to detect...
Binary Stars in the Orion Nebula Cluster (2006)
Koehler, Rainer, Petr-Gotzens, Monika G., McCaughrean, Mark J., Bouvier, Jerome, Duchene, Gaspard, Quirrenbach, Andreas, ...
We report on a high-spatial-resolution survey for binary stars in the periphery of the Orion Nebula Cluster, at 5 - 15 arcmin (0.65 - 2 pc) from the cluster center. We observed 228 stars with...
Disks around young stars with VLTI/MIDI (2006)
Van Boekel, Roy, Abraham, Peter, Correia, Serge, De Koter, Alex, Dominik, Carsten, Dutrey, Anne, ...
We report on observations of circumstellar disks around young stars that have been obtained with the MIDI instrument, which is mounted on the VLT Interferometer and operates in the 10 micrometer...
The secrets of the nearest starburst cluster: II. The present-day mass function in NGC 3603 (2006)
Stolte, Andrea, Brandner, Wolfgang, Brandl, Bernhard, Zinnecker, Hans
Based on deep VLT/ISAAC JHK photometry, we have derived the present-day mass function of the central starburst cluster NGC 3603 YC (Young Cluster) in the giant HII region NGC 3603. The effects of...
The Origin of the Initial Mass Function (2006)
Bonnell, Ian A., Larson, Richard B., Zinnecker, Hans
We review recent advances in our understanding of the origin of the initial mass function (IMF). We emphasize the use of numerical simulations to investigate how each physical process involved in...
Early ComeOn+ Adaptive Optics Observation of GQ Lup and its Substellar Companion (2006)
Janson, Markus, Brandner, Wolfgang, Henning, Thomas, Zinnecker, Hans
An analysis of adaptive optics K-band imaging data of GQ Lup acquired in 1994 by the first generation adaptive optics system ComeOn+ at the ESO 3.6m optical telescope in La Silla is presented. The...
The Low-mass Populations in OB Associations (2006)
Briceno, Cesar, Preibisch, Thomas, Sherry, William, Mamajek, Eric, Mathieu, Robert, Walter, Frederick, ...
Low-mass stars 0.1 ~< M ~< 1 Msun) in OB associations are key to addressing some of the most fundamental problems in star formation. The low-mass stellar populations of OB associations provide a...
PPV Chapter - The Formation of Brown Dwarfs (2006)
Whitworth, Anthony, Bate, Matthew R., Nordlund, Aake, Reipurth, Bo, Zinnecker, Hans
We review five mechanisms for forming brown dwarfs: (i) turbulent fragmentation of molecular clouds, producing very low-mass prestellar cores by shock compression; (ii) collapse and fragmentation of...
Disks around young stars with VLTI/MIDI (2006)
Van Boekel, Roy, Ábrahám, Péter, Correia, Serge, De Koter, Alex, Dominik, Carsten, Dutrey, Anne, ...
We report on observations of circumstellar disks around young stars that have been obtained with the MIDI instrument, which is mounted on the VLT Interferometer and operates in the 10 mum atmospheric...
The secrets of the nearest starburst cluster. II. The present-day mass function in NGC 3603 (2006)
Stolte, Andrea, Brandner, Wolfgang, Brandl, Bernhard, Zinnecker, Hans
Based on deep Very Large Telescope Infrared Spectrometer and Array Camera JHK photometry, we have derived the present-day mass function (MF) of the central starburst cluster NGC 3603 YC (Young...
The Origin of T Tauri X-ray Emission: New Insights from the Chandra Orion Ultradeep Project (2005)
Preibisch, Thomas, Kim, Yong -Cheol, Favata, Fabio, Feigelson, Eric D., Flaccomio, Ettore, Getman, Konstantin, ...
We use the data of the Chandra Orion Ultradeep Project (COUP) to study the nearly 600 X-ray sources that can be reliably identified with optically well characterized T Tauri stars (TTS) in the Orion...
Star formation in unbound giant molecular clouds: the origin of OB associations? (2005)
Clark, Paul C., Bonnell, Ian A., Zinnecker, Hans, Bate, Matthew R.
We investigate the formation of star clusters in an unbound GMC, where the supporting kinetic energy is twice as large as the cloud's self-gravity. This cloud manages to form a series of star...
The Birth of High Mass Stars: Accretion and/or Mergers? (2005)
The observational consequences of the merger scenario for massive star formation are explored and contrasted with the gradual accumulation of mass by accretion. Protostellar mergers may produce high...
Stolte, Andrea, Brandner, Wolfgang, Brandl, Bernhard, Zinnecker, Hans, Grebel, Eva K.
VLT/ISAAC JHKL photometry with subarcsecond resolution of the dense, massive starburst cluster NGC 3603 YC forming the core of the NGC 3603 giant molecular cloud is analyzed to reveal characteristics...
Gisler, Daniel, Schmid, Hans Martin, Thalmann, Christian, Povel, Hans Peter, Stenflo, Jan O., Joos, Franco, ...
A search for close companions in Sco OB2 (2003)
Kouwenhoven, Thijs, Brown, Anthony, Zinnecker, Hans, Kaper, Lex, Zwart, Simon Portegies, Gualandris, Alessia
Using adaptive optics we study the binary population in the nearby OB association Scorpius OB2. We present the first results of our near-infrared adaptive optics survey among 199 (mainly) A- and...
Microlensing by free-floating brown dwarfs (2003)
We propose a near-infrared microlensing survey of the central 2 degree field of the Galactic Center, in an attempt to estimate the surface density and mass distribution of distant free-floating brown...
Formation of massive binaries (2003)
The formation of massive stars is one of the major unsolved problems in stellar astrophysics. However, only few if any of these are found as single stars, on average massive stars have more than one...
Chances for earth-like planets and life around metal-poor stars (2003)
We discuss the difficulties of forming earth-like planets in metal-poor environments, such as those prevailing in the Galactic halo (Pop II), the Magellanic Clouds, and the early universe. We suggest...
Sills, Alison, Deiters, Stefan, Eggleton, Peter P., Freitag, Marc, Giersz, Mirek, Heggie, Douglas C., ...
This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ‘Anton Pannekoek’ in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people...
Sills, Alison, Deiters, Stefan, Eggleton, Peter P., Freitag, Marc, Giersz, Mirek, Heggie, Douglas C., ...
This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ‘Anton Pannekoek’ in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people...
Sills, Alison, Deiters, Stefan, Eggleton, Peter P., Freitag, Marc, Giersz, Mirek, Heggie, Douglas C., ...
This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ‘Anton Pannekoek’ in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people...
Sills, Alison, Deiters, Stefan, Eggleton, Peter P., Freitag, Marc, Giersz, Mirek, Heggie, Douglas C., ...
This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ‘Anton Pannekoek’ in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people...
Sills, Alison, Deiters, Stefan, Eggleton, Peter P., Freitag, Marc, Giersz, Mirek, Heggie, Douglas C., ...
This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ‘Anton Pannekoek’ in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people...
NGC 3603 - a local template for massive young clusters (2002)
Brandl, Bernhard R., Brandner, Wolfgang, Eisenhauer, Frank, Moffat, Anthony F. J., Palla, Francesco, Zinnecker, Hans
We present a study of the star cluster associated with the massive Galactic HII region NGC 3603 based on near-IR broad- and narrowband observations taken with ISAAC/VLT under excellent seeing...
A free-floating planet population in the Galaxy? (2001)
Most young low-mass stars are born as binary systems, and circumstellar disks have recently been observed around the individual components of proto-binary systems (e.g. L1551-IRS5). Thus planets and...
The Evolution of Circumstellar Disks: Lessons from the VLT and ISO (2001)
Brandner, Wolfgang, Potter, Dan, Sheppard, Scott S., Moneti, Andrea, Zinnecker, Hans
There is strong evidence that the planets in the solar system evolved from a disk-shaped solar nebula ~4.56 Gyr ago. By studying young stars in various evolutionary stages, one aims at tracing back...
The Flattened, Rotating Molecular Gas Core of Protostellar Jet HH 212 (2001)
Wiseman, Jennifer, Wootten, Alwyn, Zinnecker, Hans, McCaughrean, Mark
The recently discovered protostellar jet known as HH212 is beautifully symmetric, with a series of paired shock knots and bow shocks on either side of the exciting source region, IRAS 05413-0104...
Triggered Star Formation in the Scorpius-Centaurus OB Association (Sco OB2) (2000)
Preibisch, Thomas, Zinnecker, Hans
We explore the star formation history of the Upper Scorpius OB association, the youngest part of Sco OB2. A wide field (160 square-degree) survey for low-mass pre-main sequence (PMS) stars enabled us...
Multiplicity of massive stars (2000)
Preibisch, Thomas, Weigelt, Gerd, Zinnecker, Hans
We discuss the observed multiplicity of massive stars and implications on theories of massive star formation. After a short summary of the literature on massive star multiplicity, we focus on the O-...
Giant protostellar outflows revealed by infrared imaging (2000)
Stanke, Thomas, McCaughrean, Mark J., Zinnecker, Hans
We present new infrared data from a survey for embedded protostellar jets in the Orion A cloud. This survey makes use of the S(1) v = 1-0 line of molecular hydrogen at lambda = 2.12 mum to search for...
HH 46/47: Also a parsec scale flow (1999)
Stanke, Thomas, McCaughrean, Mark J., Zinnecker, Hans
We report the discovery of a pair of large Herbig-Haro type structures roughly 10 arcminutes (1.3 pc) north-east and south-west of the source driving the well-known HH 46/47 Herbig-Haro jet in new...
Weigelt, Gerd, Balega, Yuri, Preibisch, Thomas, Schertl, Dieter, Schoeller, Markus, Zinnecker, Hans
We present bispectrum speckle interferometry observations with the SAO 6 m telescope of the four brightest stars in the Orion Trapezium. Diffraction-limited images with an unprecedented resolution...
Search for X-ray emission from bona-fide and candidate brown dwarfs (1998)
Neuhaeuser, Ralph, Briceno, Cesar, Comeron, Fernando, Hearty, Thomas, Martin, Eduardo L., ...
Following the recent classification of the X-ray detected object V410 x-ray 3 with a young brown dwarf candidate (Briceno et al. 1998) and the identification of an X-ray source in Chamaeleon as young...
On the Formation of Massive Stars (1998)
Bonnell, Ian A., Bate, Matthew R., Zinnecker, Hans
We present a model for the formation of massive ($M > 10 M_\odot$) stars through accretion-induced collisions in the cores of embedded dense stellar clusters. This model circumvents the problem of...
Physical Properties of 90 AU to 250 AU Pre-Main-Sequence Binaries (1996)
Brandner, Wolfgang, Zinnecker, Hans
We have analyzed photometric and spectroscopic data of a sample of 14 spatially resolved pre-main-sequence binaries (separations 0.6" to 1.7") in the nearby (150 pc) low-mass star-forming regions of...
Schöller, Markus, Brandner, Wolfgang, Lehmann, Thomas, Weigelt, Gerd, Zinnecker, Hans
We present simultaneous optical and near-infrared high angular resolution observations of the close Herbig Ae/Be binary star NX Pup which is associated with cometary globule~1. The reconstructed...
Brandner, Wolfgang, Alcala, Juan M., Kunkel, Michael, Moneti, Andrea, Zinnecker, Hans
We present first results of a survey for companions among X-ray selected pre-main sequence stars, most of them being weak-line T Tauri stars (WTTS). These T Tauri stars have been identified in the...