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Annual Report 2019

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Annual Report 2019 Annual Report 2019 IRAM Annual Report 2019 Published by IRAM © 2020 Director of publication Karl-Friedrich Schuster Edited by Cathy Berjaud, Frédéric Gueth With contributions from: Sébastien Blanchet, Edwige Chapillon, Antonio Córdoba, Isabelle Delaunay, Paolo Della Bosca, Eduard Driessen, Bertrand Gautier, Olivier Gentaz, Bastien Lefranc, Santiago Navarro, Roberto Neri, Juan Peñalver, Jérôme Pety, Francesco Pierfederici, Christophe Risacher, Miguel Sánchez Portal, Murielle Serlet, Karl-Friedrich Schuster, Karin Zacher Contents Introduction 4 Highlights of research with the IRAM telescopes 6 30-meter telescope 18 NOEMA 25 Grenoble headquarters 33 Frontend Group 33 Backend Group 37 Superconducting Devices Group 39 Mechanical Group 41 Computer Group 44 Science Software 45 IRAM ARC Node 47 Outreach 47 Personnel & Finance 50 Annexes 54 Telescope schedules 54 Publications 74 Committees 94 4 Introduction This annual report has been edited during complicated times of the corona virus epidemy but this should not distract us from looking back on 2019 which was thoroughly positive for IRAM although at the same time not without new challenges. The year 2019 was rich of important events and scientific results. In fact, NOEMA and powerful new instruments at the 30-meter telescope produce so much high-quality data that we are clearly entering in a new phase of how science is done with the IRAM facilities. At the same time IRAM users have started now to fully embrace the possibilities which are available through large programs and their significant impact on all fields of millimetre wave astronomy. The required infrastructure to treat the very important data flows which are generated through large programs and the ever-increasing performance of the IRAM instruments is now reaching a mature status with the direct optical fibre connections from the observatories to the Granada office and the Grenoble headquarter, the upgraded infrastructure in data storage and computing and finally the very significant advances in data reduction software. IRAM is now half way through the second NOEMA phase with Antenna 11 foreseen to be integrated into the array in summer 2020 and the baseline extension started. This has been possible not to the least through a new strategic partnership with the University of Wisconsin Madison which was concluded in 2019. IRAM has also continued to seek collaborations on instrumentation with other leading laboratories and in particular with very fruitful exchanges with the SAO/SMA and NAOJ. 5 Meanwhile no time has been lost in the labs to develop and prototype the next technological level of instrumentation. Dual band receiver and water vapour metrology prototypes have been commissioned and the next level of bandwidth enhancement and multibeam receiver technology is under development. Obviously, the most visible event has been the publication of the first Event Horizon Telescope collaboration result, the imaging of the M87 black hole shadow. With its performance and geographic position, the IRAM 30-meter telescope was absolutely essential in taking this epoch-marking picture, for which the collaboration was awarded the Breakthrough prize 2020. Intense development efforts are underway to prepare phasing of the NOEMA antennas to support future EHT runs with NOEMA’s outstanding sensitivity. The basis of IRAM’s success remains the stable and constructive partnership among its stakeholders and the competent and highly motivated staff which has been joined by many new colleagues from all over the world during the year. For a director this is one of the most unambiguous signs that the ship is on good track. With best regards Karl-Friedrich Schuster Director Credit: DiVertiCimes Credit: 6 Institut de Radioastronomie Millimétrique Highlights of research with the IRAM telescopes Credit: EHT collaboration Credit: MMVLBI OBSERVATIONS OF THE MAGNETIC FIELD IN CTA102 Collimated jets are launched from the centers of that coincide with phases of high magnetic activity, a powerful active galactic nuclei (AGNs) and propagate team of astronomers led by Carolina Casadio (MPIfR/ at relativistic speeds, often far beyond the host Bonn) looked at polarimetric VLBI data gathered from galaxy. Helical magnetic fields anchored in either the the GMVA (86 GHz) and VLBA (43 GHz) monitoring ergosphere of a spinning supermassive black hole campaigns over the years 2016 to 2017. or the accretion disk surrounding it are thought to collimate and power these jets. Investigating the The authors of the study performed a Faraday magnetic field structure in the innermost regions rotation analysis to compare the obtained rotation of relativistic jets is fundamental to understanding measure map with the polarization evolution in the crucial physical processes giving rise to their 7 mm VLBA images. The analysis revealed a gradient formation. One of the objects in which a large-scale in the rotation measure with a maximum value of rotation measure gradient has been observed is the ~6×104 rad m−2 and intrinsic electric vector position flat-spectrum radio quasar CTA 102. angles (EVPAs) oriented around the centroid of the core that suggest the presence of large-scale helical To investigate the magnetic field structure of CTA 102, magnetic fields. Such a magnetic field structure its variability, and possibly identify physical processes seems to gain strength in the 7 mm images when Images of CTA 102 at 43 GHz (VLBA; left panel) and 86 GHz (GMVA; right panel) stacked over the years 2016 to 2017. Black sticks show the intrinsic EVPAs. The common restoring beam of 0.3×0.15 mas is displayed in the bottom-right corner. Work by Casadio et al. 2019, AA, 622, 158. Annual Report 2019 7 new superluminal components cross the core of The study suggests that the interaction between CTA 102, the brightest unresolved component in the superluminal component and the recollimation the northwestern end of the jet, and an unresolved shock could have triggered the multi-wavelength region ~0.1 mas to the south-east that the authors flares. The variability Doppler factor associated with consider to be a recollimation shock. The EVPAs such an interaction is found to be large enough to are found to change significantly between the explain the high-energy emission and the remarkable superluminal components that exit the core optical flare that occurred very close in time. and the ones that cross the stationary feature. CHARACTERIZING YOUNG PROTOSTELLAR DISKS WITH CALYPSO Understanding the first steps in the formation observational constraints on the disk size distribution of protostars and protoplanetary disks is one of in Class 0 protostars to the typical disk properties Real parts of the dust the great challenges of modern astrophysics. In from protostellar formation models, they concluded continuum emission visibilities at 1.3 mm (top) this context, Class 0 protostars are believed to that if Class 0 protostars contain similar rotational and 3.2 mm as a function of be representative of the main accretion phase of energy as is currently estimated for prestellar cores, baseline length for L1157. protostellar evolution and to retain information on then hydrodynamical models of protostellar collapse The best-t Plummer envelope (Pl) and the initial conditions of protostellar collapse. One of systematically predict a high occurrence of large Plummer+Gaussian (PG) the keys to constraining the models for the formation disks. As the CALYPSO sample rather suggests the models, and the two of protostars, and understanding their evolution to contrary, the formation of disks and multiple systems components (dashed) included in the PG model are the protostellar disk stage, lies in high-resolution during the Class 0 phase is likely to occur at smaller overplotted. millimeter studies. scales than predicted by hydrodynamical models of Work by Maury et al. 2019, rotating protostellar collapse. However, the authors AA, 621, A76. In an effort to improve the understanding of the formation of accretion disks and multiple systems during the protostellar collapse, the role of Class 0 jets and outflows in angular momentum extraction, and the kinematics and structure of the inner protostellar environment, Anaëlle Maury (AIM/CEA/CNRS/Paris) and collaborators have been working on CALYPSO (Continuum And Lines in Young ProtoStellar Objects), an IRAM Large Program. In this framework, sub- arcsecond observations using the former Plateau de Bure interferometer were obtained at 94 and 231 GHz for a sample of 16 solar-type Class 0 protostars. To identify disk-like structures embedded at small scales in the protostellar envelopes, Maury and collaborators modeled the dust continuum emission visibility profiles using Plummer-like envelope models and envelope models that include additional Gaussian disk-like components. Their analysis showed that in the CALYPSO sample about 70% of the Class 0 protostars are better reproduced by models that include a disk-like dust continuum component but that less than 25% are resolved at radii >60 au. Also, according to the study, ≤57% ± 10% of the CALYPSO sources underwent fragmentation into multiple systems over scales of 100–5000 au, which generally agrees with the multiplicity properties of Class I protostars at similar scales. By comparing the 8 Institut de Radioastronomie Millimétrique of the study point out that confirming the properties rotationally supported motions to robustly identify of the embedded protostellar structures requires disk components, or confirms the protostellar nature additional spectral line analysis that either traces of the systems at ~50 au scales. GISMO 2MM SURVEY IN THE COSMOS FIELD One of the most pressing questions in extragalactic They detect four sources at high significance astronomy concerns the production of dust in the (S/N ≥ 4.4) with an expected number of false detections very early universe. In particular, the amount of of 0.09 sources, and five sources at 4.4 > S/N ≥ 3.7 dust that could have reasonably been formed in among which 1.65 are possibly false detections. Five primordial galaxies within the first few hundred of the sources have counterparts in (sub)millimeter million years after the Big Bang is still heavily debated.
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