Multi-messenger observations of a binary neutron star merger

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

Multi-messenger Observations of a Binary Neutron Star Merger

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 {M}ȯ . 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 NGC 4993 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.</p

La perception tactile et ses implications dans la prise en charge néonatale

International audienceLe défi des soins en néonatalogie est de surmonter la discontinuité transnatale (c'est-à-dire entre les périodes prénatale et néonatale) qui est accentuée lors d'une naissance prématurée et a fortiori source de risques. Pour ce faire, des interventions thérapeutiques sont proposées dans les services de néonatologie. Elles impliquent fréquemment des stimula-tions sensorielles tactiles fondées sur l'importance de cette modalité pour le développement physique et psychologique, le bien-être et le lien d'attachement du nouveau-né humain. Pourtant, en dépit du développement précoce de la modalité tactile et de son rôle critique dans les interactions avec l'en-vironnement, nous manquons encore de connaissances fon-damentales pour comprendre son fonctionnement et ses implications à long terme sur le développement moteur, émotionnel, cognitif et social. Ces connaissances sont atten-dues des praticiens qui souhaitent proposer des interventions thérapeutiques novatrices et adaptées aux capacités de ces nouveau-nés. Ainsi, nous proposons de tirer parti des com-pétences tactiles précoces des nouveau-nés prématurés, tel-les que leurs réponses d'orientation, pour caractériser les interactions entre la perception tactile, les soins de dévelop-pement et les méthodes de prise en charge de la douleur. L'évaluation et la compréhension de ces interactions sont en effet nécessaires pour envisager des stimulations senso-rielles tactiles préventives et thérapeutiques pour les soins néonatals, qui respectent l'équilibre entre les avantages à court terme et les conséquences à long terme. Mots clés Perception tactile · Néonatalogie · Douleur · Soins de développement Abstract The challenge of neonatal care is to overcome the risks posed by the transnatal discontinuity, particularly in case of premature birth when this discontinuity occurs at a non-optimal time in development. For this reason, sensory therapeutic interventions are proposed in Neonatology units. They frequently involve tactile stimulation, based on the importance of the tactile modality for physical and psychological growth, well-being and bonding of the human neo-nate. However, despite the early development of the tactile modality and its critical role in neonatal interactions with the environment, we still lack fundamental knowledge of its functioning and long-term implications on motor, emotional, cognitive, and social development. This knowledge is needed for clinicians to propose innovative therapeutic interventions , adapted to the capabilities of premature neonates. Therefore , we propose to take advantage of tactile processing abilities in preterm neonates, like their orienting responses, to characterize interactions between tactile perception, developmental care, and pain management methods. Evaluation and understanding of these interactions are indeed necessary to imagine preventive and therapeutic tactile interventions for neonatal care, which respect the balance between short-term benefits and long-term effects