5 research outputs found

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Behavioral Health Service Delivery Among Persons with Disabilities

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    Disability is a term often viewed negatively and with inaccurate assumptions. Many of these perceptions, while typically unfounded and incorrect, have been an embedded part of our society for many years. Compounding this phenomenon is the reality that many clinicians, including behavioral health professionals, receive minimum information and training about persons with disabilities, the importance of proper language, issues they encounter, adjustment to disability concerns, or therapeutic strategies (i.e., forgiveness, self-compassion, resilience) that may be of value—all of which are considered an essential part of the therapeutic relationship. In an effort to help clinicians better understand disability and the needs of persons with disabilities, many of these areas are explored as a part of this chapter. Furthermore, information is provided regarding suggested resources and interventions that are available to help clinicians learn more about forgiveness, self-compassion, and resilience as these relate to persons with disabilities

    Sensitivity Reduction and Robustness

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