BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:The jet collimation in Cygnus A DTSTART;VALUE=DATE-TIME:20170704T120600Z DTEND;VALUE=DATE-TIME:20170704T121800Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-20@cern.ch DESCRIPTION:Speakers: Dr. BOCCARDI\, Biagina (MPIfR)\nThe powerful radio g alaxy Cygnus A is one of the very few targets where the jet acceleration a nd collimation region can be probed directly through VLBI imaging. Through a rich\, multi-wavelength VLBI data set\, we were able to reconstruct the two-sided collimation profile of the outflow\, and to follow its evolutio n from scales of a few hundreds to millions Schwarzschild radii. Prelimina ry results suggest that important transitions occur over the examined scal es. These are likely to mark changes in the physical conditions of the pla sma or of the ambient medium.\n\nhttps://events.mpifr-bonn.mpg.de/indico/e vent/43/session/1/contribution/20 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/20 END:VEVENT BEGIN:VEVENT SUMMARY:The peculiar light-curve of J1415+1320: Symmetric Achromatic Varia bility in Active Galaxies DTSTART;VALUE=DATE-TIME:20170704T133000Z DTEND;VALUE=DATE-TIME:20170704T134200Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-21@cern.ch DESCRIPTION:Speakers: Dr. MAX-MOERBECK\, Walter (MPIfR)\nI will briefly di scuss the interpretation of the peculiar light curve of J1415+1320\, that shows time-symmetric and recurring U-shaped features across the cm-wave an d mm-wave bands\, which we call Symmetric Achromatic Variability (SAV). Al though a common proposal to explain simmilar features in blazar radio ligh t curves are Extreme Scattering Events (ESEs)\, this is shown to be not vi able for this particular source. An alternative explanation involving lens ing of the jet by mass condensates in the $10^3$ to $10^6$ solar mass scal e is shown to be consistent with the observed light curves. The scales inv olved in the lens can be studied with GMVA observations\, which will allow us to test this idea.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/43 /session/5/contribution/21 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/21 END:VEVENT BEGIN:VEVENT SUMMARY:Latest developments with the Casa fringe-fitting task DTSTART;VALUE=DATE-TIME:20170704T121800Z DTEND;VALUE=DATE-TIME:20170704T123000Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-22@cern.ch DESCRIPTION:Speakers: Dr. SMALL\, Des (jive)\nAs a participant in the Blac k Hole Cam project\, JIVE undertook to develop a fringe-fitting tool in th e Casa dataprocessing package closely modeled on the AIPS FRING task. A Py thon prototype has been completed and is now in preliminary use by colleag ues at Radboud University Nijmegen\; the C++ code to apply the calibration s is now mature\, and a first draft of a C++ implementation is now complet e although many further features remain to be added.\n\nhttps://events.mpi fr-bonn.mpg.de/indico/event/43/session/1/contribution/22 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/22 END:VEVENT BEGIN:VEVENT SUMMARY:Astrometric maser measurements compared with GAIA DTSTART;VALUE=DATE-TIME:20170704T093500Z DTEND;VALUE=DATE-TIME:20170704T094700Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-1@cern.ch DESCRIPTION:Speakers: Prof. VAN LANGEVELDE\, Huib (JIVE)\nUsing Very Long Base Interferometry (VLBI)\, the Bar and Spiral Legacy (BeSSeL) survey has provided distances and proper motions for maser-bearing young massive sta rs (Reid et al. 2009\,2014)\, allowing an accurate measure of the spiral G alactic structure and kinematics. By the same technique\, we are planning to map the inner Galaxy and bulge using positions and velocities of SiO ma sers stars (Bulge Asymmetries and Dynamical Evolution - BAaDE survey: Sjou werman et al. 2015) wich are expected to be associate with evolved\, mass- loosing stars. These radio astrometric measurements (BeSSeL and BAaDE) wil l be complementary to Gaia results since\, at optical wavelengths\, the i nner plane of the Galaxy will be obscured. The overlap between optical and radio surveys provides important clues on the intrinsic properties and po pulation distribution of evolved stars. Moreover\, using radio observation s on different targets: young massive stars (BeSSeL) and AGB stars (BAaDE) \, we expect to make a fundamental comparison of Galactic parameters obtai ned with Gaia and VLBI.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/4 3/session/0/contribution/1 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/1 END:VEVENT BEGIN:VEVENT SUMMARY:e-EVN follow-up of candidate electromagnetic counterparts to GW ev ents DTSTART;VALUE=DATE-TIME:20170704T114200Z DTEND;VALUE=DATE-TIME:20170704T115400Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-0@cern.ch DESCRIPTION:Speakers: Dr. PARAGI\, Zsolt (Joint Institute for VLBI ERIC (J IVE))\nWe have established the Euro VLBI team to follow-up candidate elect romagnetic counterparts to gravitational wave events with the EVN and e-ME RLIN. The LIGO-VIRGO consortium and partners inform each other through pri vate circulars. The role of VLBI is on the one hand to help filter out som e candidates like Galactic transients or variable AGN that are not true co unterparts\, and on the other hand measure or give upper limits to the pro per motion or expansion speeds to likely extragalactic counterparts.\n\nht tps://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contribution/0 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/0 END:VEVENT BEGIN:VEVENT SUMMARY:The parsec-scale distribution of atomic hydrogen in the radio gala xy 3C236 DTSTART;VALUE=DATE-TIME:20170704T083500Z DTEND;VALUE=DATE-TIME:20170704T084700Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-3@cern.ch DESCRIPTION:Speakers: Dr. SCHULZ\, Robert (ASTRON)\nThe jets of powerful r adio galaxies are known to play a vital role in regulating the gas distrib ution of the host galaxy. Evidence for this includes observations of fast outflows of neutral hydrogen gas detected in absorption in a number of rad io galaxies\, though these observations mostly lacked the resolution to pi npoint the location of the outflow with respect to the jet system. However \, this can be achieved by Very Long Baseline Interferometry (VLBI) and it was demonstrated for the first time in 4C12.50. Based on this\, we have b een conducting a study to locate and characterise the outflow of neutral g as on parsec scales in a small sample of young and recently restarted radi o galaxies. Here\, we will present results from a global VLBI observation of the restarted giant radio galaxy 3C236 revealing a complex gas distribu tion and kinematic. The improved sensitivity and bandwidth compared to pre vious observations enable us to recover at least part of the outflowing ga s over a broad velocity range of about 600km/s and to pinpoint its locatio n to be within 40pc of the nuclear region. We also detect diffuse gas in t he region of the counter-jet lobe that is not just related to the regular rotating disk. These clouds seem to trace the gas through which the jet is travelling\, thus providing constrains on the physical conditions that co uld be important for theoretical models.\n\nhttps://events.mpifr-bonn.mpg. de/indico/event/43/session/0/contribution/3 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/3 END:VEVENT BEGIN:VEVENT SUMMARY:AGN relics in MccD Abell cluster galaxies DTSTART;VALUE=DATE-TIME:20170704T134200Z DTEND;VALUE=DATE-TIME:20170704T135400Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-2@cern.ch DESCRIPTION:Speakers: Dr. SHULEVSKI\, Aleksandar (ASTRON)\nThe high resolu tion and high sensitivity to diffuse emission at low radio frequencies mak e LOFAR a unique discovery instrument. I will outline how I use its potent ial to time the activity of AGN hosted by massive\, multi-core galaxies fo und in nearby galaxy clusters.\n\nhttps://events.mpifr-bonn.mpg.de/indico/ event/43/session/5/contribution/2 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/2 END:VEVENT BEGIN:VEVENT SUMMARY:Polarimetric Millimeter-VLBI Study of Radio Galaxy M87 and 3C84 DTSTART;VALUE=DATE-TIME:20170704T094700Z DTEND;VALUE=DATE-TIME:20170704T095900Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-5@cern.ch DESCRIPTION:Speakers: Mr. KIM\, Jae-Young (MPIfR)\nUnderstanding how mass accretion and jet formation occurs near the central engine of AGN has been one of major challenges in modern astrophyiscs. The apparent size of the jet forming region is desperately small even for an extraordinary massive BH system (10Rs=0.001pc for a BH mass of 10^9Msun)\, making a direct compa rison of theories and observations difficult. Therefore\, it is indispensa ble to image the vicinity of the SMBH and the accretion disk with ultra-hi gh resolution VLBI technique. In this talk\, I will present an observation al study of the innermost region (7 - 100s of Rs) of nearby radio galaxies M87 and 3C 84. The data obtained by global VLBI observations at 86 GHz\, with high-sensitivity stations such as the 100m GBT and the IRAM 30m being included\, reveal several new features which were not seen by previous VL BI at lower-resolution and/or lower-frequency. Analysis and interpretation of the total intensity and linear polarization structures will be mainly presented.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/43/session/0/c ontribution/5 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/5 END:VEVENT BEGIN:VEVENT SUMMARY:Preparing a Proof-Of-Concept Observation with the Juelich Solar Po wer Tower DTSTART;VALUE=DATE-TIME:20170704T115400Z DTEND;VALUE=DATE-TIME:20170704T120600Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-4@cern.ch DESCRIPTION:Speakers: Dr. ROY\, Alan (MPIfR)\nSKA phase 2 sensitivity coul d be achieved at relatively low cost if we\ncan piggyback a radio astronom y receiver on solar concentrators\, of\nwhich four square kilometres are o perating in the form of solar power\ntowers. However the mirror arrays fo rm a speckle pattern rather than\na point focus\, but we can restore full sensitivity in principle using\na focal-plane array to collect the power f rom the many speckles and\nsum it coherently. That is\, provided we can p redict the speckle\npattern from the array geometry sufficiently well. Ce rtainly in\nsimulations it works perfectly well.\n\nTo test this in practi ce we are preparing a proof-of-concept\nexperiment on the Juelich research SPT\, for simplicity starting with a\nsingle-pixel receiver and with Effe lsberg to serve as a\nphase-reference antenna for obtaining the speckle ph ases as well as\namplitudes in a single-baseline VLBI experiment.\n\nThis talk will give background and simulation results and sketch our\nplans for the first observation.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/4 3/session/1/contribution/4 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/4 END:VEVENT BEGIN:VEVENT SUMMARY:How to make fast radio bursts smile for the photograph DTSTART;VALUE=DATE-TIME:20170704T113000Z DTEND;VALUE=DATE-TIME:20170704T114200Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-7@cern.ch DESCRIPTION:Speakers: HOUBEN\, Leonard ()\nFast radio bursts (FRBs) are a new radio transient phenomena that puzzles scientists over their nature. T hese millisecond\, Janksky bright single pulses are seen with dispersion m easures (DMs) several times larger then those caused by the electron densi ty in our own Milky Way and therefore thought to be of extra-galactic orig in. Their non-repetitive behaviour (only one FRB has seen to repeat thus f ar) and the majority being single-dish detections make it hard to pinpoint their exact location on the sky and deduce which sources produce them. Ef forts by the MPIfR and Radboud University try to resolve this issue using the unique properties of LOFAR to catch and image the dispersion tail of t he same FRB as detected in real-time with the Effelsberg Telescope. Detect ion of the same FRB is possible because of the large dispersive delay betw een the two observatories of several seconds to a few minutes. Once LOFAR receives a trigger from Effelsberg upon the detection of an FRB in the lat er\, LOFAR's Transient Buffer Boards (TBBs) are frozen and read out to obt ain low frequency\, high time and frequency resolution data of the burst. Due to LOFAR's long baselines this data can then be used to image the dete cted FRB and localise it down to several arc-seconds. A multitude of so lo calised FRBs might shed some light on their progenitors and unravel their nature.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/43/session/1/cont ribution/7 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/7 END:VEVENT BEGIN:VEVENT SUMMARY:Tracing the fundamental jet properties in the gamma-ray active 201 3+370 blazar DTSTART;VALUE=DATE-TIME:20170704T125400Z DTEND;VALUE=DATE-TIME:20170704T130600Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-6@cern.ch DESCRIPTION:Speakers: Ms. TRAIANOU\, Efthalia (MPIfR)\nBlazars\, a subclas s of AGN jets\, show extreme flux variability across the\nelectromagnetic spectrum from radio to gamma-rays. A challenge to theoretical\ninterpretat ion is the rapid flux variability at GeV energies\, which implies\nan orig in from ultra-compact emission regions (\n\nhttps://events.mpifr-bonn.mpg. de/indico/event/43/session/1/contribution/6 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/6 END:VEVENT BEGIN:VEVENT SUMMARY:Kinematics and radio emission of the multiple stellar systems AB D or and HD 160934 DTSTART;VALUE=DATE-TIME:20170704T135400Z DTEND;VALUE=DATE-TIME:20170704T140600Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-9@cern.ch DESCRIPTION:Speakers: Dr. AZULAY\, Rebecca S. (MPIfR)\nRadio observations play an important role to understand the processes involved in the formati on and evolution of stellar and substellar objects. In this context\, we h ave made several contributions to binary stars belonging to the AB Doradus moving group\, namely\, AB Dor A/C (Guirado et al. 2006\; 2011)\, AB Dor Ba/Bb (Azulay et al. 2015)\, and\nHD 160934 A/c (Azulay et al. 2014\; 2017 ). In these cases\, VLBI astrometric programs provided precise estimates o f the dynamical mass of the individual components\, providing relevant res ults in terms of calibration of the mass-luminosity relationship for young \, low-mass objects. We intend to extend the study of these binaries with new observations at different frequencies directed to characterize the rad io emission from each one of the components and to refine the determinatio n of the orbital elements and dynamical masses.\n\nhttps://events.mpifr-bo nn.mpg.de/indico/event/43/session/5/contribution/9 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/9 END:VEVENT BEGIN:VEVENT SUMMARY:3mm GMVA observations of total and polarised emission from blazar and radio galaxy core regions. DTSTART;VALUE=DATE-TIME:20170704T092300Z DTEND;VALUE=DATE-TIME:20170704T093500Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-8@cern.ch DESCRIPTION:Speakers: Dr. CASADIO\, Carolina (MPIfR)\nWe present total and linearly polarised 3 mm GMVA images of a 
sample of blazars and radio g alaxies from the VLBA-BU-BLAZAR 7 mm monitoring 
program aimed to probe the innermost regions of AGN jets and locate the sites 
of gamma-ray em ission observed by Fermi-LAT. The reduced opacity at 3 mm and improved a ngular resolution\, of the order of 50 $\\mu$arcseconds\, allow us to esti mate the angular sizes and magnetic field structure of the most compact fe atures\, which can be compared with those observed at 7 mm with the VLBA f or the determination of the jet's physical parameters. We also compare two different methods used for the calibration of instrumental polarisation a nd we present the results applied to some of the sources in the analysed s ample.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contr ibution/8 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/8 END:VEVENT BEGIN:VEVENT SUMMARY:Welcome Address DTSTART;VALUE=DATE-TIME:20170704T083000Z DTEND;VALUE=DATE-TIME:20170704T083500Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-11@cern.ch DESCRIPTION:Speakers: Prof. ZENSUS\, J. Anton ()\nWelcome Address\n\nhttps ://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contribution/11 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/11 END:VEVENT BEGIN:VEVENT SUMMARY:Low frequencies and interplanetary scintillation: Peaked-spectrum sources at high-redshift? DTSTART;VALUE=DATE-TIME:20170704T140600Z DTEND;VALUE=DATE-TIME:20170704T141800Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-10@cern.ch DESCRIPTION:Speakers: Dr. CALLINGHAM\, Joseph (ASTRON)\nMany active galact ic nuclei (AGN) show a spectral peak in their radio spectra. Peaked-spectr um radio sources (including gigahertz-peaked spectrum and compact steep sp ectrum sources) are radio galaxies that often display small angular extent s\, suggesting that they are either very young AGN or are confined by a de nse surrounding medium. We here present a spectacular sample of 1484 low-f requency peaked-spectrum sources derived from the Murchison Widefield Arra y's GLEAM survey\; for 95% of this sample\, the peaked spectral behaviour is newly identified. We will also discuss the use of interplanetary scinti llation to constrain the arcsecond scale of many of these sources at 150 M Hz\, exploring the possibility that the combination of an observed MHz pea k and small radio structure at 150 MHz are good identifiers to find radio sources at redshifts greater than 5.\n\nhttps://events.mpifr-bonn.mpg.de/i ndico/event/43/session/5/contribution/10 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/10 END:VEVENT BEGIN:VEVENT SUMMARY:VLBI and gamma-ray studies of radio galaxies DTSTART;VALUE=DATE-TIME:20170704T084700Z DTEND;VALUE=DATE-TIME:20170704T085900Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-13@cern.ch DESCRIPTION:Speakers: Mr. ANGIONI\, Roberto (MPIfR)\nThe $\\gamma$-ray sky is strongly dominated by blazars\, i.e. AGN with relativistic jets orient ed closely with our line of sight. Radio galaxies are their misaligned cou nterpart\, and make up about $\\sim$1-2% of all AGN observed by *Fermi*-LA T. Nonetheless\, they provide us with a view of AGN jets which is less bia sed by Doppler boosting effects\, and allow us to test jet production and emission models in light of the unified scheme of radio-loud AGN. The comb ination of $\\gamma$-ray data and high-resolution VLBI studies is a powerf ul tool in order to investigate these objects. We present an ongoing study focused on the radio galaxies in the southern-hemisphere VLBI (and multi- wavelenght) monitoring program TANAMI. We combine VLBI kinematics at 8.4 G Hz with $\\gamma$-ray monitoring provided by *Fermi*-LAT. Here we present the results on the $\\gamma$-ray detected sources (Pictor A\, PKS 0521$-$3 6\, PKS 0625$-$35\, Centaurus B and PKS 1718$-$649).\n\nhttps://events.mpi fr-bonn.mpg.de/indico/event/43/session/0/contribution/13 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/13 END:VEVENT BEGIN:VEVENT SUMMARY:RoboPol: The optical polarization of gamma-loud and gamma-quiet bl azars DTSTART;VALUE=DATE-TIME:20170704T141800Z DTEND;VALUE=DATE-TIME:20170704T143000Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-12@cern.ch DESCRIPTION:Speakers: Dr. ANGELAKIS\, Emmanouil (MPIfR)\nAfter a review of the robopol project and its main findings in the angle domain\, we will p resent average R-band optopolarimetric data\, as well as variability param eters\, from the first and second RoboPol observing season. We investigate whether gamma-ray-loud and gamma-ray-quiet blazars exhibit systematic dif ferences in their optical polarization proper- ties. We find that gamma-ra y-loud blazars have a systematically higher polarization fraction (0.092) than gamma-ray-quiet blazars (0.031)\, with the hypothesis of the two samp les being drawn from the same distribution of polarization fractions being rejected at the 3σ level. We have not found any evidence that this discr epancy is related to differences in the redshift distribution\, rest-frame R-band luminosity density\, or the source classification. The median pola rization fraction versus synchrotron-peak-frequency plot shows an envelope implying that high-synchrotron-peaked sources have a smaller range of med ian polarization fractions con- centrated around lower values. Our gamma-r ay-quiet sources show similar median polarization fractions although they are all low-synchrotron-peaked. We also find that the randomness of the po larization angle depends on the synchrotron peak frequency. For high-synch rotron-peaked sources\, it tends to concentrate around preferred direction s while for low-synchrotron-peaked sources\, it is more variable and less likely to have a preferred direction. We propose a sce- nario which mediat es efficient particle acceleration in shocks and increases the helical B-f ield component immediately downstream of the shock.\n\nhttps://events.mpif r-bonn.mpg.de/indico/event/43/session/5/contribution/12 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/12 END:VEVENT BEGIN:VEVENT SUMMARY:​Studies of circumstellar shells in AGB stars by ​mm-VLBI obse rvations of maser emission DTSTART;VALUE=DATE-TIME:20170704T091100Z DTEND;VALUE=DATE-TIME:20170704T092300Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-15@cern.ch DESCRIPTION:Speakers: Dr. COLOMER\, Francisco (JIVE)\nVLBI observations of maser emission are a basic tool to study the​ ​circumstellar envelope s (CSEs) around evolved stars\, mainly around AGB​ ​and post-AGB stars . The maser lines of water and silicon monoxide​ ​are particularly int ense. They provide us with ​h​igh spatial resolution data on the very inner CSEs around AGB stars\, including the pulsating layers previous to g rain formation and​ ​outer regions w​h​ere the fast expansion char acteristic of such ​e​nvelopes is already present. ​The analysis of the pumping mechanism of SiO masers and of the physical conditions in the emitting clumps requires accurate maps of the various lines\, which show d ifferent excitation requirements. We will discuss recent observations of S iO masers with the Global Millimeter VLBI Array (GMVA) which\, when compar ed with the maps of other SiO lines\, provide a new view into the physics of these AGB envelopes.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/4 3/session/0/contribution/15 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/15 END:VEVENT BEGIN:VEVENT SUMMARY:Jet spectral properties from matched-resolution ground/space VLBI observations DTSTART;VALUE=DATE-TIME:20170704T124200Z DTEND;VALUE=DATE-TIME:20170704T125400Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-14@cern.ch DESCRIPTION:Speakers: Ms. VEGA GARCÍA\, Laura (MPIfR)\nI will present new results on spectral index imaging of several AGN using multi-frequency sp ace VLBI observations with RadioAstron\, in combination with ground array images. I will introduce a GUI-based Python tool for spectral analysis of VLBI data\, that was used to produce the results.\n\nhttps://events.mpifr- bonn.mpg.de/indico/event/43/session/1/contribution/14 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/14 END:VEVENT BEGIN:VEVENT SUMMARY:Water masers and the death of stars DTSTART;VALUE=DATE-TIME:20170704T143000Z DTEND;VALUE=DATE-TIME:20170704T144200Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-17@cern.ch DESCRIPTION:Speakers: Dr. OROSZ\, Gabor (JIVE)\nStars similar to our Sun u ndergo radical changes as their lives draw to an end. After swelling up to huge red giants\, they start to pulsate\, blowing off large clouds of gas and dust\, to create intricately shaped and mesmerizing planetary nebulae . The remaining part of the star collapses under gravity\, creating a comp act white dwarf to slowly cool and fade away. One of the pivotal questions in this evolutionary scenario is how to explain the shapes of planetary n ebulae\, whose morphology depart significantly from spherical symmetry. Fo rtunately\, we can use VLBI observations of water masers to get some insig ht into the last throes of dying stars by tracing their powerful molecular jets forming and shaping their environments. In my talk I will show resul ts from such VLBI observations to get an idea on how stars like our Sun be have when they finally die.\n\nhttps://events.mpifr-bonn.mpg.de/indico/eve nt/43/session/5/contribution/17 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/17 END:VEVENT BEGIN:VEVENT SUMMARY:VLBI astrometry of nearby star-forming regions DTSTART;VALUE=DATE-TIME:20170704T144200Z DTEND;VALUE=DATE-TIME:20170704T145400Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-16@cern.ch DESCRIPTION:Speakers: Dr. ORTIZ-LEÓN\, Gisela Noemí (MPIfR)\nWe use the VLBI technique to obtain precise astrometric measurements to several young stars in nearby star-forming regions belonging to the galactic structure known as the Gould's Belt. These measurements will allow us to investigate the structure of the clouds and their internal kinematics and eventually to characterize the overall dynamics of the Belt. I will present the curre nt status of the project focusing on three regions for which accurate dist ances and proper motions have been collected: Ophiuchus\, Serpens and Orio n. In addition\, I will discuss how the high angular resolutions achieved with this technique will allow us to characterize the population of young\ , very tight\, binary and multiple systems. Our results will be relevant t o test the astrometry quality of both VLBI and Gaia observations by consid ering objects that both instruments can detect.\n\nhttps://events.mpifr-bo nn.mpg.de/indico/event/43/session/5/contribution/16 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/5/contributio n/16 END:VEVENT BEGIN:VEVENT SUMMARY:The Africa Millimetre Telescope DTSTART;VALUE=DATE-TIME:20170704T123000Z DTEND;VALUE=DATE-TIME:20170704T124200Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-19@cern.ch DESCRIPTION:Speakers: Dr. MUELLER\, Cornelia (Radboud University)\nThe Eve nt Horizon Telescope (EHT) project aims to image the\nsupermassive black h oles in the center of our Galaxy (Sgr A*) and M87 at\nevent horizon scales using very long baseline interferometry (VLBI) at\n(sub-)millimetre wavel engths. The EHT currently consists of a number\nof telescopes around the g lobe. A telescope in Africa will greatly improve the\nuv-coverage and the image quality. We propose to build a mm-wave radio\ntelescope on the Gams berg in Namibia. This location has many\nadvantages: for example\, the Gal actic Center passes almost exactly\noverhead and there is mutual visibilit y on Sgr A* with the IRAM\ntelescopes\, SPT\, LMT\, and the ALMA.\nIn this talk\, I will give an overview and update on the current status of the pr oject.\n\nhttps://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contr ibution/19 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/1/contributio n/19 END:VEVENT BEGIN:VEVENT SUMMARY:A Global Millimeter VLBI Array Survey of Compact Extra Galactic Ra dio Sources at 86 GHz DTSTART;VALUE=DATE-TIME:20170704T085900Z DTEND;VALUE=DATE-TIME:20170704T091100Z DTSTAMP;VALUE=DATE-TIME:20260608T174300Z UID:indico-contribution-43-18@cern.ch DESCRIPTION:Speakers: Ms. G. NAIR\, Dhanya (MPIfR)\nVery Long Baseline Int erferometry (VLBI) Observations at 86$\\\,$GHz reach a resolution of about 50 $\\mu$as and sample the scales as small as 10$^3$--10$^4$ Schwarzschi ld radii of the central black hole in Active Galactic Nuclei (AGN)\, and u ncover the jet regions where acceleration and collimation of the relativis tic flow takes place. Synchrotron radiation becomes optically thin at mill imetre wavelengths\; making it possible to look deeper into the core and i nner jets of AGN which are invisible at centimetre and longer wavelengths due to self-absorption or free-free absorption by the torus. We present th e results from a large global VLBI survey of 162 ultra compact radio sourc es at 86 GHz conducted in 2010 -- 2011. This survey has contributed an inc rease of $\\sim$ 2 on the total number of AGNs imaged with VLBI at 86 GHz . The survey data attained a baseline sensitivity of 0.1 Jy and a typical image sensitivity of 5 mJy/beam.\n\nWe have used Gaussian model fitting to represent the structure of the observed sources and to estimate the flux densities and sizes of the core and jet components. The model fitting yiel ds estimates of the brightness temperature ($T_\\mathrm{b}$) of the VLBI b right core (base) of the jet and inner jet components of AGN\, taking into account the resolution limits of the data at 3mm. We have applied a basic population model with a single value of intrinsic brightness temperature\ , $T_\\mathrm{0}$\, in order to reproduce the observed distribution of $T_ \\mathrm{b}$. In this talk\, the analysis and the results of the basic po pulation model will be presented. We also present the brightness temperatu re limits made directly from the visibility data.\n\nhttps://events.mpifr- bonn.mpg.de/indico/event/43/session/0/contribution/18 LOCATION:MPIfR 0.02 URL:https://events.mpifr-bonn.mpg.de/indico/event/43/session/0/contributio n/18 END:VEVENT END:VCALENDAR