Identifying Compact Symmetric Objects in the Southern Sky

We present results of multifrequency polarimetric VLBA observations of 20 compact radio sources. The observations represent the northern and southern extensions of a large survey undertaken to identify Compact Symmetric Objects (CSOs) Observed in the Northern Sky (COINS). CSOs are young radio galaxies whose jet axes lie close to the plane of the sky, and whose appearance is therefore not dominated by relativistic beaming effects. The small linear sizes of CSOs make them valuable for studies of both the evolution of radio galaxies and testing unified schemes for active galactic nuclei (AGN). In this paper we report on observations made of 20 new CSO candidates discovered in the northern and southern extremities of the VLBA Calibrator Survey. We identify 4 new CSOs, and discard 12 core-jet sources. The remaining 4 sources remain candidates pending further investigation. We present continuum images at 5 GHz and 15 GHz and, where relevant, images of the polarized flux density and spectral index distributions for the 8 new CSOs and CSO candidates.Comment: accepted to Ap

A Compact Supermassive Binary Black Hole System

We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black hole pair yet found by more than two orders of magnitude. These results are based upon recent multi-frequency observations using the Very Long Baseline Array (VLBA) which reveal two compact, variable, flat-spectrum, active nuclei within the elliptical host galaxy of 0402+379. Multi-epoch observations from the VLBA also provide constraints on the total mass and dynamics of the system. Low spectral resolution spectroscopy using the Hobby-Eberly Telescope indicates two velocity systems with a combined mass of the two black holes of ~1.5 x 10^8 solar masses. The two nuclei appear stationary while the jets emanating from the weaker of the two nuclei appear to move out and terminate in bright hot spots. The discovery of this system has implications for the number of close binary black holes that might be sources of gravitational radiation. Green Bank Telescope observations at 22 GHz to search for water masers in this interesting system are also presented.Comment: 34 pages, 7 figures, Accepted to The Astrophysical Journa

Liquid Phase Electrochemistry at Ultralow Temperatures

Fluid electrolyte solutions based on mixtures of butyronitrile (PrCN) and ethyl chloride (EtCl) with or as electrolyte freeze below −180°C and provide excellent media for cryogenic electrochemical experiments. A 1:2 mixture of PrCN and EtCl exhibits the best combination of freezing point and ionic conductivity for ultralow temperature electrochemistry. Diffusion coefficients for bis(pentamethylcyclopentadienyl) iron are measurable by potential step chronoamperometry down to −160°C using a conventionally sized electrode, but the resistivity of the solvent mixture is such that potential sweep voltammetry benefits from the use of microdisk (10 and 25 μm diam Pt) or microband (0.2 μm wide Au) electrodes. Voltammetry at a chemically modified electrode down to −170°C is presented for the case of thin films

P3_6 Cavorite Pt 2: the Gravity of the Situation

We continue to explore the gravitational and atmospheric effects of Cavorite, a fictional material that is “opaque to gravitation”, by attempting to form a simplified gravitational model of the situation. This gravitational model was found to define the range at which gravitational acceleration will return to near normal as between 0.02 and 12 m. Further research is required to truly model the gravitational acceleration due to Cavorite

P3_3 On the Atmospheric Effects of Cavorite

We estimate the gravitational and atmospheric effects of a fictional substance known as Cavorite, a material proposed by H.G. Wells that is “opaque to gravitation”. We conclude that for a Cavorite sheet of radius 1 m the impact on the gravitational acceleration is only meaningful at less than 12 m above the plate, and is insignificant at heights greater than this. Therefore, the atmosphere is unlikely to vent away as claimed

P3_4 Elysium: Where'd the Atmosphere Go?

This paper determines whether the Elysium space station, from the 2013 film Elysium[1], could maintain an atmosphere. We found that Elysium, with a radius of 20 km[2], would not hold onto its atmosphere unless high wind speeds (183 ms^-1, 324 ms^-1, and 443 ms^-1; for the atmospheric rotations tested) are to be endured by its inhabitants

P3_5 On the minimum mass for a Death Star's power system

We examine the minimum mass necessary to build the power system for a "Death Star", as shown in the "Star Wars" series of films, using current technology. Considering its powerplant as a Carnot engine we are able to find a balance between the necessary mass of reactor and heat radiators so as to reduce the overall mass of the Death Star's power system to 6.8 x 10^25 kg, approximately 930 times the mass of Earth's moon (to 2 significant figures)

P3_9 Scooby and Shaggy: Metabolic Miracles

In the cartoon `What's New Scooby-Doo?' the characters Shaggy and Scooby are seen to eat large volumesof food without gaining any weight. Their effective temperatures in order to radiate away the excess energywere calculated to be T_Sh ~ 97 ± 033 °C for Shaggy, and T_Sc ~ 140 ± 43 °C for Scooby. It was concludedthat under normal circumstances, the subjects would perish of extreme hyperthermia. It was also notedthat Shaggy could survive if he was able to sweat continuously at the maximum rate for a human

P3_1 On the feasibility of neutrino sails

In this paper we consider whether a neutrino sail, a sheet of material absorbing neutrinos and gaining thrust from their momentum change, is a viable method of spacecraft propulsion. We calculate the thrust that could be achieved per unit area and compare this to that possible using a photon solar sail. We also calculate the thickness of sail necessary assuming that there are no special conditions under which the cross section for neutrino interactions with nuclei can be increased. We find that a thickness of 34000 light years would be necessary if a sheet of osmium were used, whereas neutron star matter could achieve this at 189 km thickness. We conclude that a neutrino sail is not a practical method of propulsion