• Canada
• Research dataclose
• 2021-2021close
• Natural Sciences and Engineering Research Council of Canada close
• EC|H2020 close
• EU close
• IT close
• NEANIAS Atmospheric Research Community close

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. To support the physical interpretation and modeling, the EHT Collaboration partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength (MWL) campaign. We release the processed data from MWL observations of M87 in easily downloadable formats, as a legacy product of the EHT 2017 campaign on M87. In the paper associated with this data release, The EHT MWL Science Working Group et al. (2021), we present the most complete simultaneous, MWL spectrum of the active nucleus to date, as well as discuss the complexity and caveats of combining data from different spatial scales into a single broadband spectrum. In addition to the MWL spectrum as the primary data product, we also release machine-readable versions of other tables presented in the Appendix of the paper, intermediate data products of the X-ray analysis, and sampled posteriors of X-ray and MWL model parameters. A brief description of MWL observations and data processing is provided within the repository with further details presented in the associated paper.Please cite both the paper and the repository if using these data products in your publication.

VizieR online Data Catalogue associated with article published in journal Astronomical Journal (AAS) with title 'A decade of multiwavelength observations of the TeV blazar 1ES 1215+303: extreme shift of the synchrotron peak frequency and long-term optical-gamma-ray flux increase.' (bibcode: 2020ApJ...891..170V)

This study examines the Holocene evolution of an inland subarctic permafrost peatland located on the north bank of Wiyâshâkimî Lake (Nunavik, northeastern Canada). The analysis of plant macrofossils allowed us to reconstruct the succession of the trophic conditions of a palsa and a filled thermokarst pond. The accumulation of organic matter began at around 6290 cal. y BP. The evolution of the site then followed three stages: a pond (6290–5790 cal. y BP), a minerotrophic peatland (5790–4350 cal. y BP) and an ombrotrophic peatland (from 4350 cal. y BP). The establishment of permafrost caused a palsa to form at around 170 cal. y BP, which corresponds to the coldest period of the Little Ice Age in northeastern Canada. A subsequent degradation of the palsa and the formation of a thermokarst pond were induced by the climate warming that began at the turn of the 20th century. The analysis of plant macrofossils from an adjacent filled thermokarst pond indicated three phases of development over a short 450-year period: subaquatic, minerotrophic, and ombrotrophic phases. When combined with previous studies of filled thermokarst ponds in northern Québec, this result indicates that ponds are rapidly filling in with vegetation and acting as carbon sinks.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) offers micron-resolution 2D chemical imaging, which has been adapted recently to ice core analysis. Measurements were performed in 2020 at the Ca’Foscari University of Venice, in order to investigate the localization of impurities in the ice samples. Here an image is presented from applying LA-ICP-MS elemental imaging to a glacial (MIS2, bag 1065) samples of the EPICA Dome C ice core from central Antarctica. Lateral resolution is 35 microns both along and perpendicular to the scan direction. Considered as analytes are 23Na, 25Mg and 88Sr. Background and drift correction as well as image construction were performed using the software HDIP (Teledyne Photon Machines, Bozeman, MT, USA). Impurity images are acquired as a pattern of lines, without overlap in the direction perpendicular to that of the scan, and without any further spatial interpolation. Each pixel in an ice core chemical image has a size of 35 μm x 35 μm. For each chemical element the datasets comprise a numerical matrix which contains rows and columns according to the physical size of the image: an image of 7 mm x 35 mm in size has 200 rows and 1000 columns. The numerical entries in this matrix refer to the recorded intensity (e.g. in counts). Values lower than the detection limit are set to zero. Due to the careful synchronization, the individual pixels of the different chemical channels can be considered to be almost perfectly spatially aligned. In contrast, the mosaic of visual images obtained from the laser camera is not a-priori aligned with the chemical images. The visual images are generally characterized by air bubbles (dark blobs), grain boundaries (dark lines) and occasional sub-grain boundaries (thin dark lines).