The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

International Basic Safety Standards – Protecting people and the environment

An interim edition of the IAEA Safety Requirements document: “Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards” (BSS) was published in November 2011. The revision of the BSS was coordinated by a BSS Secretariat consisting of representatives of the IAEA, FAO, EC, ILO, UNEP, PAHO, WHO and NEA/OECD. The BSS takes into account the Fundamental Safety Principles, the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation and the 2007 recommendations of the International Commission of Radiological Protection (ICRP) and other applicable ICRP statements and publications. This paper provides an overview of the revised BSS, including requirements on preparedness for a nuclear or radiological emergency and to remediation of areas contaminated by residual radioactive material following a nuclear or radiological emergency