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Heidelberg
Heidelberg is well-known of its medieval Castle ruins, Old Bridge, Christmas Market, and the long pedestrian shopping street. It is a traditional and lively student town, with the Rupreht Karl University of Heidelberg holding the post of the oldest university in Germany.
Heidelberg harbors several astronomical institutes with hundreds of astronomers altogether. This makes Heidelberg one of the largest astronomical communities in Germany and in Europe.
Heidelberg is located about an hour train/shuttle bus travel away from the Frankfurt airport (FRA), with connections running about hourly.
The Institute
Max-Planck-Institute for Astronomy (MPIA) in Heidelberg employs ~350 people with ~230 scientists, including ~90 PhD students. In addition to science in the fields of planet- and star formation and galaxies and cosmology, MPIA is strongly involved in current state-of-the-art instrumentation projects such as the Large Binocular Telescope, the Herschel satellite, and the Very Large Telescope.
MAX-PLANCK-INSTITUTE FOR ASTRONOMY
http://www.mpia-hd.mpg.de/
INTERNATIONAL MAX PLANCK RESEARCH SCHOOL
http://www.mpia.de/imprs-hd/Goal: To establish the connection between the large-scale
molecular cloud structure and star formation.
ASSEMBLING
MAX-PLANCK-INSTITUTEFOR ASTRONOMY
PROJECT BROCHURE
MOLECULAR CLOUDS
Credit: ESO/GigaGalaxy Zoom project
Credit: MPIA
Jouni [email protected]
CONTACT:Jouni [email protected]
CONTACT:
Assembling Molecular CloudsBackground
Formation of dense, self-gravitating structures inside more diffuse, large-scale molecular clouds is the ultimate prerequisite for star formation. The collapse of such structures inevitably leads to formation of stars, and thus the basic properties of the stars themselves are connected to those of the self-gravitating structures. Because of this connection, determining the origin of various stellar properties, such as their initial mass function (IMF), requires understanding the properties of the self-gravitating structures: What drives the formation of these structures in the clouds? What are the conditions necessary for their formation? How efficiently can they form stars? These questions are in the very focus of the current star formation research.
Clearly, understanding the scale and nature of star formation observed in molecular clouds is intricately linked to understanding structure formation inside them. Consequently, attaining observational constraints for the processes that shape the cloud structure during the cloud evolution is one of the key topics in the current efforts to understand global laws of star formation. In particular, constraining those processes requires characterization of the ISM structure prior to the active star-forming phase of the ISM.
Science goal
“Assembling molecular clouds” is a research project dedicated to studying how, and through which processes, the molecular cloud structure evolves during the transition from quiescence to active star formation. This goal is intricately linked to assessing the physical connection between the diffuse cloud component and self-gravitating cores in the clouds.
Approach
“Assembling Molecular Clouds” quantifies the physical processes acting in molecular clouds in a very early stage of their evolution, even prior to active star formation. This is accomplished through sensitive observations of cloud structure and dynamics at various spatial scales and through comparison of such data to theoretical predictions for, and simulations of, the molecular cloud structure.
Observations are gathered both from nearby molecular clouds in which the cloud structure can be studied in high spatial resolution and from more distant clouds in which potential high-mass star-forming sites reside. This allows building a picture covering the entire mass-scale relevant for star formation.
The observational techniques involved in the program include near-infrared, (sub-)millimeter dust emission, and molecular l ine emiss ion observat ions . Observational programs are being carried out by, e.g., the ESO/VLT, IRAM, and Calar Alto observatories.
Recent publications:
✦ “Mass reservoirs surrounding massive infrared dark clouds: a view by dust extinction”
Kainulainen et al. (2011a, arXiv:1109.6017)✦ “Coalsack Near and Far” Beuther et al. (2011, A&A, 533, 17)
✦ “Probing the evolution of molecular cloud structure II: From Chaos to Confinement”
Kainulainen et al. (2011b, A&A, 530, 64)✦ “Star formation in the Taurus Filament L1495: From
dense cores to stars” Schmalzl et al. (2010, ApJ, 725, 1327)✦ “Probing the evolution of molecular cloud structure
II: From Chaos to Confinement” Kainulainen et al. (2009, A&A, 508L, 35)
Collaborators:
Alves, Joao Banerjee, RobiBeuther, Henrik Federrath, ChristophHenning, Thomas Li, HuabaiTan, Jonathan ....
Jouni Kainulainen ([email protected])CONTACT:
RESEARCH HIGHLIGHTS
From Chaos to Confinement -- In a recent paper series (Kainulainen et al. 2009, 2011a), we employed near-infrared dust extinction data and discovered a new trend in h o w m o l e c u l a r c l o u d s assemble themselves prior to star formation. Our findings suggest that the pressure condit ions play a more significant role in forming dense cores inside clouds
than earlier accounted for.
Peering to the Distance -- Probing molecular clouds forming high-mass stars is difficult because of the confusion towards the Galactic plane where they reside. In Kainulainen et al. (2011b), we presented a new method to estimate gas column densities towards these objects.
The Bull’s Tail -- The nearby Taurus molecular cloud is one of the best places to study cloud
fragmentation in high resolution. In Schmalzl et al. (2010), we derived an unprecedentedly sensitive view towards a filamentary structure in Taurus to study its fragmentation into clumps and dense cores.1330 SCHMALZL ET AL. Vol. 725
Figure 5. Extinction map of the Filament L 1495 with a resolution of 0.′9 derived from deep NIR observations with Omega2000. Contours are plotted in steps ofAV = 5 mag. We separate the filament into different subregions, which conform to Barnard’s dark objects (Barnard et al. 1927). The boxes indicate the positions ofthe zoom-ins shown in Figure 6.
Figure 6. Zoom-ins into the extinction map. The scale bar indicated in the bottom panel is common to all sub-plots. Contours are plotted in steps of 5σ each. Thepositions of dense cores mapped in NH3 (Jijina et al. 1999) and H13CO+ (OMK02) are overplotted alongside YSOs (Rebull et al. 2010).
sources with outliers in extinction, which might be caused byintrinsically different colors (e.g., YSOs, brown dwarfs, etc.).For our map, we chose a resolution of 0.′9 as a compromisebetween resolving the small-scale structures in the filament andhaving low noise over the dynamical range covering most of themap. In this resolution, the map covered the dynamical rangeof AV = 1.5–35 mag. The noise of the final map depends onextinction, being σ = 0.5 mag at AV = 0 mag and σ = 2 magat AV = 35 mag.
Figure 5 shows the resulting extinction map, with blowupsof different regions of it shown in Figure 6. The map re-veals, on one hand, a remarkably well-defined, high as-pect ratio filamentary structure and, on the other hand, com-plex clumpy substructures within this filament. We notethat within the mapped region we find six Barnard objects,namely the clumps B 211, B 213, B 216, B 217, B 218(which represent the filament), and B 10 (which forms thehub).
