The First Simultaneous 3.5 and 1.3mm Polarimetric Survey of Active Galactic Nuclei in the Northern Sky

Short millimeter observations of radio-loud AGN offer the opportunity to study the physics of their inner relativistic jets, from where the bulk millimeter emission is radiated. Millimeter jets are significantly less affected by Faraday rotation and depolarization than in radio. Also, the millimeter emission is dominated by the innermost jet regions, that are invisible in radio owing to synchrotron opacity. We present the first dual frequency simultaneous 86GHz and 229GHz polarimetric survey of all four Stokes parameters of a large sample of 211 radio loud active galactic nuclei, designed to be flux limited at 1Jy at 86GHz. The observations were most of them made in mid August 2010 using the XPOL polarimeter on the IRAM 30 m millimeter radio telescope. Linear polarization detections above 3 sigma median level of ~1.0% are reported for 183 sources at 86GHz, and for 23 sources at 229GHz, where the median 3 sigma level is ~6.0%. We show a clear excess of the linear polarization degree detected at 229GHz with regard to that at 86GHz by a factor of ~1.6, thus implying a progressively better ordered magnetic field for blazar jet regions located progressively upstream in the jet. We show that the linear polarization angle, both at 86 and 229GHz, and the jet structural position angle for both quasars and BL Lacs do not show a clear preference to align in either parallel or perpendicular directions. Our variability study with regard to the 86GHz data from our previous survey points out a large degree variation of total flux and linear polarization in time scales of years by median factors of ~1.5 in total flux, and ~1.7 in linear polarization degree -maximum variations by factors up to 6.3, and ~5, respectively-, with 86% of sources showing linear polarization angles evenly distributed with regard to our previous measurements.Comment: Submitted for Publication in Astronomy & Astrophysics. 14 pages (including 2 tables and 18 figures

Radiative decays of mesons in the NJL model

We revisit the theoretical predictions for anomalous radiative decays of pseudoscalar and vector mesons. Our analysis is performed in the framework of the Nambu-Jona-Lasinio model, introducing adequate parameters to account for the breakdown of chiral symmetry. The results are comparable with those obtained in previous approaches.Comment: 19 pages incl. 4 figure

Social Networking: An astronomer's field guide

We present a brief introduction to the phenomenon of "social networking" and its potentially powerful use as an astronomy outreach and educational tool. We briefly discuss the development of applications for websites and facebook and the use of web trackers e.g. Google Analytics to analyze your audience. Finally we discuss how social bookmarking can be used to promote your work to unexpected audiences.Comment: 10 pages, conferenc

Non-Special Loudspeakers as Speech Test Sources in Natural Acoustics Speech Intelligibility Investigations

Objective speech intelligibility estimations undertaken in natural acoustics speech communications (NAS) scenarios require the utilization of a speech source that approximates the acoustic characteristics of a human talker. Only a limited number of special speech sources that conform to the specifications in the relevant guidelines are available in the market; however, they can be deemed expensive by professional practitioners and other users. Non-special and affordable loudspeakers are often used in NAS investigations in place of standardized special speech sources without the knowledge of their suitability and results validity. This study aims to examine the suitability of a range of representative common and affordable non-special loudspeakers as a potential alternative to standardized speech sources in NAS indicative or pilot investigations. Frequency response and Speech Transmission Index Public Address (STIPA) experimental results obtained from a reference standardized speech source were compared against results from various non-special loudspeakers measured utilizing diverse and real-world representative combinations of NAS acoustic conditions under controlled laboratory conditions. STIPA mean absolute errors for the alternative speech sources were generally lower than the STIPA method uncertainty and one Just Noticeable Difference (0.03 STI). The findings of this study will inform practitioners of the suitability of affordable loudspeakers when standardized special test loudspeakers are not availabl

THE VALUE OF USDA OUTLOOK INFORMATION: AN INVESTIGATION USING EVENT STUDY ANALYSIS

The economic value of public situation and outlook information has long been a subject of debate. The purpose of this paper is to investigate the economic value of USDA WASDE reports in corn and soybean markets. The investigation is based on event study analysis, with the "events" consisting of the release of all monthly USDA WASDE reports for corn and soybeans from 1985 through 1998. The WASDE reports during the sample period are divided into two groups: one that represents "pure" outlook information and one that represents a "mix" of situation and outlook information. The statistical tests can be placed into two categories: mean price reaction and volatility reaction. Overall, the results suggest that USDA outlook information has a significant impact in corn and soybean markets. The most notable impact is found in options markets, where implied volatility consistently declines after the release of WASDE reports. For the group of monthly reports containing only outlook information, implied volatility for both corn and soybeans was lower on the report day than on the previous day about 60 percent of the time. The difference in mean implied volatility on the day of the report and on the previous day for both corn and soybeans was significantly different from zero. The average magnitude of the drop was between about two- and three-tenths of a percentage point (of annualized implied volatility), which would appear to be an economically non-trivial decrease. Hence, it can be concluded that USDA outlook information reduces the uncertainty of market participants' expected distribution of future prices. This reduction in market uncertainty is unambiguously welfare-enhancing.Crop Production/Industries, Marketing,

The dust morphology of the elliptical Galaxy M86 with SPIRE

We present Herschel-SPIRE observations at 250–500 μm of the giant elliptical galaxy M 86 and examine the distribution of the resolved cold dust emission and its relation with other galactic tracers. The SPIRE images reveal three dust components: emission from the central region; a dust lane extending north-south; and a bright emission feature 10 kpc to the south-east. We estimate that ~10^6 M_☉ of dust is spatially coincident with atomic and ionized hydrogen, originating from stripped material from the nearby spiral NGC 4438 due to recent tidal interactions with M 86. The gas-to-dust ratio of the cold gas component ranges from ~20–80. We discuss the different heating mechanisms for the dust features

Acoustic wave propagation through eco-friendly porous panels at normal incidence

Human and non-human subjects are exposed to micro plastics through drink, food, and air. Micro-plastics propagating through atmosphere are breathable particles during inhalation and exhalation leading to deposition of them in the deep lung via the alveoli of the lungs. Teabags are made of plastics that are not recyclable and biodegradable. Therefore, we intend to remove used teabags from the natural environment by repurposing them to make sound attenuating panels for building and architectural industries, contributing in this way to a sustainable circular economy. The panels were designed and developed from consumed teabags as porous material by filling a frame to investigate acoustics wave propagation through them at normal incidence. Experimental testing was carried out on circular teabag panels in an impedance tube using a transfer function method to determine their sound absorption coefficient and transmission loss. Furthermore, the impedance gun method was used to determine the absorption properties of square panels. Results show that 75 mm thick circular panels give an absorption coefficient higher than 0.8 between 400 and 1600 Hz. Up-to 9.8 dB sound transmission loss of circular panels is obtained at higher frequencies. Absorption coefficients for square teabag panels are very good despite a coincidence-dip seen at 800 Hz. The satisfactory sound absorption and sound transmission characteristics of acoustic panels made of consumed tea bags can make this recycled material a cost-effective solution in the production of sustainable acoustic treatment in indoor spaces. The results suggest that recycling of consumed teabag as the panel could be applied as alternative sound absorbing materials

Pair Plasma Dominance in the Parsec-Scale Relativistic Jet of 3C345

We investigate whether a pc-scale jet of 3C345 is dominated by a normal plasma or an electron-positron plasma. We present a general condition that a jet component becomes optically thick for synchrotron self-absorption, by extending the method originally developed by Reynolds et al. The general condition gives a lower limit of the electron number density, with the aid of the surface brightness condition, which enables us to compute the magnetic field density. Comparing the lower limit with another independent constraint for the electron density that is deduced from the kinetic luminosity, we can distinguish the matter content. We apply the procedure to the five components of 3C345 (C2, C3, C4, C5, and C7) of which angular diameters and radio fluxes at the peak frequencies were obtainable from literature. Evaluating the representative values of Doppler beaming factors by their equipartition values, we find that all the five components are likely dominated by an electron-positron plasma. The conclusion does not depend on the lower cutoff energy of the power-law distribution of radiating particles.Comment: 17 page