Tuesday. The last few days were: Saturday: Hiking in the Swiss alps. Sunday: pooped out in the Zürich ITP institute apartment, laundry, then flying into Köln. Monday: Moving into the Uni guest house, meeting Peter Schneider, settling into my new office. Today, I met a lot of colleagues.
UBonn Master-Kolloquium
Multi-epoch VLBI mapping of the globular cluster M15. A pulsar proper motion analysis.
Franz Kirsten
M15 hosts two low-mass X-ray binaries (LMXB), at least 8 millisecond pulsars (MSP), and shows evidence to host an intermediate mass black hole (IMBH). Perform proper motion analysis using VLBI 1.6 GHz at high spectral resolution. In addition, we search for new compact radio sources (LMXB or MSP candidates), and signature for the central IMBH candidate. This talk is about the first 4 observation epochs (out of 7).
* 中途半端だなあ。面白いのかな？
UBonn Promotions-Kolloquium (Ph.D. defense)
Hish resolution magnetic field measurements in high-mass star-forming regions
Gabirele Surcis
Few scenarios proposed to explain the formation of high-mass stars. The role of magnetic fields during the protostellar phase of high-mass star-formation is a debated topic. One of the high-mass stellar formation scenario is core accretion: massive stars form through gravitational collapse, involving disk-assisted accretion to overcome radiation pressure. This scenario is similar to the low-mass star-formation, where magnetic fields are thought to play an important role by removing excess angular momentum, allowing accretion to continue onto the star. However, it is still unclear how magnetic fields influence the formation and dynamics of disks and outflows. Most current information on magnetic fields close to high-mass protostars comes from polarized maser emissions, which allow us to investigate the magnetic field on small scales (10s-1000s of AU) by using interferometers (EVN, MERLIN, VLBA). Investigate magnetic fields in 7 massive star-forming regions by observing polarized emission of methanol and water masers at milliarcsecond resolution.
* results?
UCB Astro Colloquium
Observing the Growth of the most massive black holes at high redshifts
Benny Trakhtenbrot (Tel Aviv)
Most significant growth epoch of the majority of the SMBHs must have occured at z>1-2. Measure BH masses and accretion rates in several high-z AGNs, based on NIR spetro campaigns. Focus on z~5 AGNs observed in VLT/Gemini, which show lower masses and higher accretion rates than AGNs at z~2-3.5. Combine both observations to show clear evolution: the z~5 BHs grow through Eddington-limited accretion from a broad range of seed masses. Their subsequent growth (at duty cycles of 10-20%) forms the most massive BHs observed at z~2 (accretion rate slow? is that what they mean by duty cycle of 10-20%?). Follow-up campaigns which aim at understanding the co-evolution of the BHs with their host galaxies.
LBL INPA
A New view of the CMB from ACT
Sudeep Das (BCCP)
CMB small-scale fluctuations will show gravitational lensing of the CMB. A new way to constrain DE, and prospects for cross-correlations with other data sets. Polarized counderpart of ACT--the ACTPol project, a premier CMB lensing experiment. What kind of science can it do? Cross-correlate with optical lensing and galaxy surveys.
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