Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded

Elicitor of the β-Thujaplicin Accumulation in Callus Cultures of Cupressus lusitanica.

The addition of yeast extract to callus cultures of Cupressus Zusitanica leads to a large increase in the production of p- thujaplicin that acts as a phytoalexin of the treated cultures. y- Thujaplicin was not formed in any appreciable amounts. The content usually reached S- 16 mg/g of dry weight of callus in 6 days of incubation after the addition of yeast extract. This accumulation of P - thujaplicin suggested the presence of elicitor components in the yeast extract. Therefore, the extract was fractionated by means of ethanol precipitation, ribonuclease treatment and complexation with the Fehling reagent. Some fractions of the extract actively induced the P - thujaplicin accumulation in the Cupressus Zusitanica callus. The most effective fraction was purified about 50 - fold over unfractionated extract, and was a polysaccharide which was composed of mainly mannose, glucose, and to a lesser degree ribose residues