Svitlana Zhukovska
(MPIA)
27/04/2015, 15:30
Prof.
Robi Banerjee
(Universität Hamburg)
28/04/2015, 16:30
Volker Ossenkopf
(Universität Köln)
29/04/2015, 09:00
Session1, Wednesday
Unfortunately, it is impossible to resolve the full three-dimensional distribution of densities, velocities and magnetic fields in molecular clouds through astronomical observations as we are bound to celestial positions and a frequency scale. The frequency scale, allows to address the velocity distribution through molecular line observations. The relation between underlying ppp-structures and...
Jonathan Mackey
(AIfA, Uni Bonn, and I. Physikalisches Institut, Uni. Köln)
29/04/2015, 09:15
Mass loss from massive stars is very important for determining their evolution and death, but their wind properties can be difficult to measure and are often very uncertain. Main sequence massive stars have fast and highly ionized winds, driving bubbles in their surroundings that have proven surprisingly difficult to detect. We have run simulations showing that wind bubbles are typically...
Prof.
Stefanie Walch
(Universität zu Köln)
29/04/2015, 09:30
Session1, Wednesday
Molecular clouds are cold, dense, and turbulent filamentary structures that condense out of the multi-phase interstellar medium. They are also the sites of star formation. The minority of new-born stars is massive, but these stars are particularly important for the fate of their parental molecular clouds as their feedback drives turbulence and regulates star formation.
I will present results...
Svitlana Zhukovska
(MPIA)
29/04/2015, 09:45
Session1, Wednesday
Interstellar dust is an ubiquitous component of the ISM playing an active role in shaping its physical and chemical structure from the earliest evolution of galaxies. In order to improve the understanding of dust properties as a function of environment we employ models of dust evolution, including main sources and sinks of dust and constraints from observations. Local dwarf galaxies allow to...
Sebastian Haid
(Universität zu Köln)
29/04/2015, 10:00
Session1, Wednesday
Supernovae inject a large amount of energy and momentum into the interstellar medium. This is important to set phase structures, regulate star formation or drive outflows. An immediate result of this interaction is turbulence, also in the surroundings of supernovae. The density profile of the ambient medium crucially influences the evolution of the remnant.
We provide a semi-analytic...
Tobias Röhser
(Universität Bonn)
29/04/2015, 10:10
Session1, Wednesday
Intermediate-Velocity Clouds (IVCs) are HI clouds in the lower galactic halo that are thought to be related to a galactic fountain process. Most IVCs are predominantly atomic with a negligible fraction of molecular hydrogen (H_2) while molecular IVCs (MIVCs) are extremely rare. With respect to the galactic fountain hypothesis, IVCs and in particular MIVCs might be an important ingredient for...
Annika Franeck
(Universität zu Köln)
29/04/2015, 10:20
C+ fine structure emission has recently been studied with Herschel and Sofia.
The results promote C+ as a tracer for star formation in galactic discs or CO-dark molecular gas. Furthermore, the scale height of the C+ emission in the Milky Way and in distant galaxies is not well understood. Does it trace the disc dynamics?
Using RADMC-3D, we post-process three-dimensional,...
Dr
Sandra Brünken
(Universität zu Köln)
29/04/2015, 11:00
Session2, Wednesday
Contributed talk
Sandra Brünken and Stephan Schlemmer, I. Physikalisches Institut, Universität zu Köln, Germany
The PAH hypothesis associates the unidentified infrared (UIR) emission bands observed in many astronomical environments to the fluorescence of large polycyclic aromatic hydrocarbons (PAHs) that are excited by the interstellar radiation field. Whereas the presence of PAHs in space is now widely...
Dr
Melanie Schnell
(Universität Hamburg)
29/04/2015, 11:15
Session2, Wednesday
Contributed talk
The observed variations in molecular abundances in interstellar space originate from both physical and chemical reasons. We will use a combination of chirped-pulse Fourier transform rotational spectroscopy in different frequency ranges with telescope observations to analyse the molecular composition of the universe. By exploring the interstellar molecular complexity and by discovering new...
Dr
Cornelia Jäger
(Friedrich-Schiller-Universität Jena)
29/04/2015, 11:30
Session2, Wednesday
Contributed talk
The condensation of carbonaceous and siliceous dust under conditions prevailing in molecular clouds has been experimentally studied. For this purpose, molecular species including refractory elements were deposited on cold substrates. The gaseous precursors of such condensation processes in the ISM are formed by erosion of dust grains in supernova shocks. In the laboratory, we have produced the...
Pierre Mohr
(Friedrich Schiller University Jena)
29/04/2015, 11:45
Session2, Wednesday
Contributed talk
P. Mohr, F. Lewen, H. Mutschke
In this project, we have synthesized glassy Mg-Fe silicates as interstellar-dust analog materials and have determined their absorption/emission coefficients at low temperatures in the wavelength range from 50 micrometers to 4 millimeters. We have found a strong dependence of the dust opacity on the temperature and a moderate depencence on the chemical...
Daniel Lenz
(Universität Bonn)
29/04/2015, 11:55
Session2, Wednesday
Contributed talk
The correlation between neutral hydrogen and dust has been extensively studied since the IRAS mission. This led to important insights into gas and dust physics, the accretion history of the Milky Way and eventually the distribution of the CO-dark molecular gas. For a full-sky analysis, the spatial resolution of these studies was limited by the angular resolution of the HI data of about one...
Prof.
Thomas Giesen
(Universität Kassel)
29/04/2015, 14:30
Short carbon chains are fundamental for the chemistry of stellar and interstellar ambiances: They are omnipresent throughout the interstellar medium, they likely participate in the formation of long carbon chains and they are products in photo-fragmentation processes of larger species. Triatomic carbon C3 exhibits a mid-infrared ν3 antisymmetric stretching mode and a ν2 bending vibration at...
Dr
Matthias Gritschneder
(Universitaetssternwarte Muenchen)
29/04/2015, 14:45
We investigate the fate of B44, a giant trunk in the Ophiuchus region. Employing the AMR-code RAMSES, we are able to show that the wisps and striations visible in the recent Planck Observations can be explained by the hydrodynamical interaction of the trunk with the wind caused by the massive stars in this region.
Dr
Martin Krause
(MPE)
29/04/2015, 15:00
Session2, Wednesday
Contributed talk
The Scorpius Centaurus OB association (parallactic distances 118-145 pc) is the closest massive star group to the Sun. Its extent of more than 50 degrees on the sky ensures spatially resolved information from radio up to gamma ray frequencies. We analyse multiwavelength data for the different gaseous component: hot X-ray emitting bubbles, swept-up HI and molecular shells, dusty filaments and...
Anna Faye Mc Leod
(ESO)
29/04/2015, 15:15
Session2, Wednesday
Contributed talk
The results of the first publication from our FuSIOn (Feedback in massive star forming regions: from SImulations to Observations) project, in which we seek to validate the predictions of numerical simulations of star forming clouds that include feedback in the form of stellar winds and photo-ionisation by comparing them with observations, are presented. We observed the iconic Pillars of...
Mrs
Anna Schauer
(Universität Heidelberg)
29/04/2015, 15:25
Session2, Wednesday
Contributed talk
Population III (or Pop III) stars can influence their surroundings in several ways and by so doing regulate subsequent star formation. Their radiation may ionize or photodissociate H2 in the surrounding interstellar medium and break out to affect other halos. Even if ionizing photons are trapped, Lyman-Werner (LW) photons may still escape the halo and photodissociate H2 in nearby halos,...
Katharina Wollenberg
(Universität Heidelberg)
29/04/2015, 15:35
Session2, Wednesday
Contributed talk
J031300 is now the most metal-poor star discovered to date, with a maximum Fe abundance of 10^(-7.1) solar. Two possible Pop III supernova candidates have been identified, with progenitor masses of 12.4 and 60 Msun, whose nucleosynthetic yields that are a good match to the chemical abundances found in J031300. However, explaining the actual metallicity of J031300 also requires an...
Philipp Schneider
(USM/LMU)
29/04/2015, 17:05
Mr
Alessandro Ballone
(USM/MPE, Garching)
29/04/2015, 17:15
Session2, Wednesday
Contributed talk
The evolution of the dust cloud G2, discovered by Gillessen et al. (2012), has been continuously monitored from 2004 to now. The most recent position-velocity diagrams, obtained from the integral field spectrograph SINFONI at VLT, clearly show that G2 has experienced the pericenter passage. Thus, G2 is now subject to the maximum tidal field of the supermassive black hole and hydrodynamical...
Sara Rezaei Khosbakht
(MPIA Heidelberg)
29/04/2015, 17:25
Session2, Wednesday
Contributed talk
Sara Rezaei Kh., C. A. L. Bailer-Jones, R. J. Hanson
Max-Planck-Institut fϋr Astronomie, Kӧnigstuhl 17, 69117 Heidelberg, Germany
We present a non-parametric model to mode probabilistically the three-dimensional distribution of dust in the Milky Way. Knowledge of dust distribution in the Galaxy is required when estimating intrinsic stellar properties which are in turn necessary to estimate...
Daniel Kröll
(Universität Bonn)
29/04/2015, 17:35
Session2, Wednesday
Contributed talk
Superbubbles and bubbles in the interstellar medium are formed by winds of massive stars and their supernova explosions. Knowing the properties of these bubbles is key to determine the energy input by stellar groups and its history.
We study the hydrogen structures in the vicinity of the closest OB Association, the Scorpius-Centaurus association at 140 pc distance. We investigate if our model...
Benjamin Gaczkowski
(USM/LMU)
30/04/2015, 09:00
Session2, Wednesday
Contributed talk
Today molecular cloud formation is attributed to collisions of large-scale flows in the ISM. Such flows can be driven by stellar feedback processes and supernovae. The numerous massive stars in the three sub-groups of the Sco-Cen OB-association created a huge system of expanding loop-like H I structures around each of the sub-groups. The Lupus I molecular cloud is situated in the middle...
Dr
Guang-Xing Li
(USM)
30/04/2015, 09:15
Session2, Wednesday
Contributed talk
In this talk I will present the G-virial method, which allows to quantify (1) the importance of gravity in molecular clouds in the position-position-velocity (PPV) space, and (2) properties of the gas condensations in molecular clouds. After introducing the method, I will discuss how to study the importance of gravity in star formation, and how we can link different models and simulations with...
Dr
Alberto Sanna
(MPIfR Bonn)
30/04/2015, 09:30
Session2, Wednesday
Contributed talk
At an early stage of stellar evolution, massive young stellar objects (YSOs) inject large amounts of mechanical energy into the ISM by powerful outflow phenomena, which are a main outcome of mass accretion onto the protostar. In turn, this outflow activity provides a major source of turbulent energy for the cluster gas. In this context, it is fundamental to properly characterize the dynamical...
Simon Glover
(Universität Heidelberg)
30/04/2015, 09:45
Session2, Wednesday
Contributed talk
Numerical simulations of star formation and stellar feedback have now advanced to the point where they routinely include relatively sophisticated treatments of the microphysics of the ISM. However, much of the predictive power of these simulations can only be harnessed if we can convert their results into synthetic observables that can be compared with observations of the real ISM. In this...
Ms
María Jesús Jiménez
(Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Germany)
30/04/2015, 10:00
Session2, Wednesday
Contributed talk
The efficiency of star formation in other galaxies is often studied only focusing on molecular gas traced by CO emission due to the faintness of other lines. However the emission coming from lines such as HCN or HCO+ is an essential tool to probe the actual dense gas.
Therefore one of the key ways to probe the physics conditions in the star forming gas and as importantly, study if and how...
Volker Weiss
(TLS Tautenburg)
30/04/2015, 10:10
Proto-stellar outflows are a signpost of stellar birth. Despite many investigations of such flows, their impact on the parental molecular cloud is still highly disputed. Simulations suggest that proto-stellar outflows are too weak to replenish turbulent energy globally, and thus have little influence on stabilizing the cloud. On the other hand, observations show that outflows can generate...
Nicolas Guillard
(ESO)
30/04/2015, 10:20
Session2, Wednesday
Contributed talk
Observations of dwarfs galaxies suggest that Black Holes (BHs) and Nuclear Clusters (NCs) are co-evolving with their hosts. However, their formation and how they are fueled is still unclear. NCs, unlike BHs, may provide a visible record of the accretion of stars and gas. Therefore, they can be used as probes for the gas and star fueling of the nuclei of dwarfs galaxies.
Whether NCs form via...
Neven Tomicic
(MPIA)
30/04/2015, 10:25
Session2, Wednesday
Contributed talk
The cold interstellar medium (ISM) provides the raw materials out of which stars form. However, many open questions remain regarding how cooling, phase transitions, star formation, and feedback interplay, what the effects of both local and global environment on these processes are, and how they connect to large scale galaxy evolution. Many of these processes, which occur on <<100 pc spatial...
Timea Csengeri
(MPIfR Bonn)
30/04/2015, 11:00
Session2, Wednesday
Contributed talk
The ATLASGAL survey is one of the most sensitive and extensive ground-based survey of the inner Galaxy at sub-millimeter wavelengths, and provides an unprecedented view on all stages of massive star formation. Over 10 000 compact sources have been identified (Csengeri et al. 2014), and we have made substantial progress in characterising various evolutionary stages of the evolution of massive...
Katharina Fierlinger
(LMU)
30/04/2015, 11:15
Giant molecular clouds (GMCs) are reshuffled by stellar winds and supernova explosions of massive stars. These processes -- which we call stellar feedback -- create bubbles in the interstellar medium and insert newly produced heavy elements and kinetic energy into their surroundings, possibly driving turbulence in GMCs. Most of this energy is thermalized and immediately removed from the GMC by...
Mr
Andrea Gatto
(Max Planck Institute for Astrophysics)
30/04/2015, 11:30
Session2, Wednesday
Contributed talk
Supernova (SN) explosions are an important component for shaping the interstellar medium (ISM). They produce its hottest phase while driving turbulent motions in the warm and cold gas. Globally, these random motions could provide a net turbulent support and help to regulate star formation. The impact of SNe on the ISM is, however, strongly dependent on the thermodynamic properties of the...
Anabele-Linda Pardi
(Max-Plank-Institut fur Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany)
30/04/2015, 11:40
Session2, Wednesday
Contributed talk
We carry out three-dimensional MHD simulations of the magnetised multiphase interstellar medium (ISM) focusing on the connection between chemical and magnetic evolution. The simulations of periodic boxes include a complex chemical network tracking molecule formation and destruction. We also include supernova (SN) feedback.
Magnetic field saturation occurs when the field dissipation and...
Anabele-Linda Pardi
(Max-Plank-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany)
30/04/2015, 11:40
Session2, Wednesday
Contributed talk
Co-authors: Philipp Girichidis1, Thorsten Naab1, Stefanie Walch2, Andrea Gatto1, Richard Wünsch3, Simon C.O. Glover4, Ralf S. Klessen4,5,6, Paul C. Clark7, Christian Baczynski4, Thomas Peters1,8
1Max-Plank-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
2Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
3Astronomical...
Maximilian Eisenreich
(MPA)
30/04/2015, 11:50
Session2, Wednesday
Contributed talk
We use hydrodynamical simulations to study the influence of AGN accretion and feedback on the late morphological and kinematic evolution of the hot and cold interstellar medium and young stars in isolated early-type galaxies (ETGs). The complex interplay of gas cooling from a hot halo, feedback from star formation (metal and energy return from supernova Ia and II, AGB winds) and gas accretion...
Caroline Reinert,
Harald Mutschke
(Friedrich Schiller University Jena)
30/04/2015, 14:30
Surprisingly little data are available on the absorption/emission index of water ice for submillimeter wavelengths. We present new spectroscopic measurements for crystalline water ice cooled to low temperatures and derive a simple T-dependent model for the opacity based on power laws
Dr
Sunil Kumar Sudhakaran
(Max-Planck-Institut für Kernphysik)
30/04/2015, 14:45
Session2, Wednesday
Contributed talk
One of the long-standing mysteries in astronomy is the origin of the interstellar absorption features that are observed in the visible to near infrared range and dubbed as the diffuse interstellar bands (DIBs). Despite the observation of several hundred lines, none of them has been unambiguously attributed to a chemical species. A potential candidate believed to be responsible for some of...
Udo Ziegler
(AIP)
Session2, Wednesday
Contributed talk
The interaction of supernova remnants with interstellar clouds can produce dense gas aggregations which eventually get compressed enough to form prestellar cores. Numerical simulations of shocked clouds by isolated supernova remnants help to filter necessary conditions for core triggering and to enlighten the role of individual physical processes involved like magnetohydrodynamics, radiative...
Dr
Nicola Schneider
(LAB Bordeaux)
Session2, Wednesday
Contributed talk
Since long, there are claims that stars form only above certain thresholds of (column) density, and that the rate of star formation (SFR) in a galaxy can be linked to physical properties of the interstellar gas from which stars are forming. With the Herschel photometric maps (70-500 micron) of Galactic clouds, it is now possible to determine rather precisely their column density structure,...
