7,150 research outputs found

    Galaxy-Targeting Approach Optimized for Finding the Radio Afterglows of Gravitational Wave Sources

    Get PDF
    Kilonovae and radio afterglows of neutron star merger events have been identified as the two most promising counterparts, of these gravitational wave sources, that can provide arcsecond localization. While several new and existing optical search facilities have been dedicated to finding kilonovae, factors such as dust obscuration and the daytime sky may thwart these searches in a significant fraction of gavitational wave events. Radio-only searches, being almost immune to these factors, are equally capable of finding the counterparts and in fact offer a complementary discovery approach, despite the modest fields of view for many of the present-day radio interferometers. Such interferometers will be able to carry out competitive searches for the electromagnetic counterparts through the galaxy targeting approach. Adapting and improving on an existing algorithm by Rana et al. 2017. we present here a method that optimizes the placement of radio antenna pointings, integration time, and antenna slew. We simulate 3D gravitational wave localizations to find the efficacy of our algorithm; with substantial improvements in slew overhead and containment probability coverage, our algorithm performs significantly better than simple galaxy-rank-ordered observations. We propose that telescopes such as the Very Large Array, MeerKAT, Australia Telescope Compact Array and the Gaint Meterwave Radio Telescope, having fields of view \lesssim1 deg2^2 and searching for the counterparts of nearby GW events over tens of square degrees or larger, will especially benefit from this optimized galaxy-targeting approach for electromagnetic counterpart searches.Comment: 13 pages, 7 figures, Submitted to Ap

    Fluctuation relations for heat engines in time-periodic steady states

    Full text link
    A fluctuation relation for heat engines (FRHE) has been derived recently. In the beginning, the system is in contact with the cooler bath. The system is then coupled to the hotter bath and external parameters are changed cyclically, eventually bringing the system back to its initial state, once the coupling with the hot bath is switched off. In this work, we lift the condition of initial thermal equilibrium and derive a new fluctuation relation for the central system (heat engine) being in a time-periodic steady state (TPSS). Carnot's inequality for classical thermodynamics follows as a direct consequence of this fluctuation theorem even in TPSS. For the special cases of the absence of hot bath and no extraction of work, we obtain the integral fluctuation theorem for total entropy and the generalized exchange fluctuation theorem, respectively. Recently microsized heat engines have been realized experimentally in the TPSS. We numerically simulate the same model and verify our proposed theorems.Comment: 9 page

    Hospice and Oncology Nurses’ Perspectives on Legalizing Physician-Assisted Suicide in California: A Pilot Study

    Get PDF
    People are living with congenital anomalies, chronic diseases, and disabilities. It is universally agreed upon that every human being has a right to life, however, there is no unanimous decision regarding the right to death. Of the hospice nurses and social workers in Oregon, two-thirds of them reported having a patient ask them about the PAS option (Miller, Harvath, Ganzini, Goy, Delorit, & Jackson, 2004) California, Oregon, Vermont, and Washington have all legalized physician-assisted suicide through legislation. California’s law, the right to death passed on September 11th, 2015. The purpose of this research study is to examine hospice and oncology nurses’ perspectives of Physician-Assisted Suicide. Current research is inconclusive. Further research is necessary to understand how nurse\u27s religion or spiritual framwork affects attitudes, what are ethical alternatives, and what are common perceptions of PAS, etc. This research was guided by the research question; how do hospice and oncology nurses describe the positive and negative aspects of PAS? According to the American Nurses Association (ANA) Code of Ethics for Nurses with Interpretive Statements (2001), “the nurse should not participate in assisted suicide. Such an act is in violation of the Code for Nurses with Interpretive Statements and the ethical traditions of the profession. Nurses, individually and collectively, have an obligation to provide comprehensive and compassionate end-of-life care which includes the promotion of comfort and the relief of pain, and at times, foregoing life-sustaining treatments”. Yet, the same passage states that nurses must intervene to relieve pain and suffering of the dying patient, even if the interventions hasten death

    Evaporation Channel as a Tool to Study Fission Dynamics

    Full text link
    The dynamics of the fission process is expected to affect the evaporation residue cross section because of the fission hindrance due to the nuclear viscosity. Systems of intermediate fissility constitute a suitable environment for testing such hypothesis, since they are characterized by evaporation residue cross sections comparable or larger than the fission ones. Observables related to emitted charged particle, due to their relatively high emission probability, can be used to put stringent constraints on models describing the excited nucleus decay and to recognize the effects of fission dynamics. In this work model simulations are compared with the experimental data collected via the ^{32}S + ^{100}Mo reaction at E_{lab}= 200 MeV. By comparing an extended set of evaporation channel observables the limits of the statistical model and the large improvement coming by using a dynamical model are evidenced. The importance of using a large angular covering apparatus to extract the observable is stressed. The opportunity to measure more sensitive observables by a new detection device in operation at LNL are also discussed.Comment: v1: 7 pages, 6 figure
    corecore