Isotope effect for associative detachment: H(D)−+H(D)→H2(D2)+e

We report experimental and theoretical results for associative detachment (AD) of D−+D→D2+e−. We compare these data to our previously published results for H−+H→H2+e−. The measurements show no significant isotope effect in the total cross section. This is to be contrasted with previously published experimental and theoretical work which has found a significant isotope effect in diatomic systems for partial AD cross sections, i.e., as a function of the rotational and vibrational levels of the final molecule formed. Our work implies that though the rovibrational distribution of flux is different for AD of H− + H and D− + D, the total flux for these two systems is essentially the same when summed over all possible final channels

NGC 4993, the shell galaxy host of GW170817: constraints on the recent galactic merger

International audienceContext. NGC 4993 is the shell galaxy host of the GRB170817A short gamma-ray burst and the GW170817 gravitational-wave event produced during a binary-neutron-star coalescence.Aims. The galaxy shows signs, including the stellar shells, that it has recently accreted a smaller, late-type galaxy. The accreted galaxy might be the original host of the binary neutron star.Methods. We measured the positions of the stellar shells of NGC 4993 in an HST/ACS archival image and use the shell positions to constrain the time of the galactic merger.Results. According to the analytical model of the evolution of the shell structure in the expected gravitational potential of NGC 4993, the galactic merger happened at least 200 Myr ago, with a probable time roughly around 400 Myr, and the estimates higher than 600 Myr being improbable. This constitutes the lower limit on the age of the binary neutron star, because the host galaxy was probably quenched even before the galactic merger, and the merger has likely shut down the star formation in the accreted galaxy. We roughly estimate the probability that the binary neutron star originates in the accreted galaxy to be around 30%.Key words: galaxies: interactions / galaxies: peculiar / galaxies: individual: NGC 4993 / gravitational waves / stars: neutron / gamma-ray burst: individual: GRB 170817

The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory

The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and admin-istrative staff in Malargtie. We are very grateful to the following agencies and organizations for financial support: Argentina - Comision Nacional de Energia Atomica; Agencia Nacional de Promocion Cientffica y Tecnologica (ANPCyT) ; Consejo Nacional de Investigaciones Cientfficas y Tecnicas (CONICET) ; Gobierno de la Provincia de Mendoza; Municipalidad de Malargtie; NDM Holdings and Valle Las Leas; in gratitude for their continuing cooperation over land access; Australia - the Australian Research Council; Brazil - Conselho Nacional de Desenvolvi-mento Cientffico e Tecnologico (CNPq) ; Financiadora de Estudos e Projetos (FINEP) ; FundacAo de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ) ; SAo Paulo Research Foundation (FAPESP) Grants No. 2019/101512, No. 2010/07359-6 and No. 1999/054043; Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC) ; Czech Republic - Grant No. MSMT CR LTT18004, LM2015038, LM2018102, CZ.02.1.01/0.0/0.0/16_013/0001402,CZ.02.1.01/0.0/0.0/18_046/0016010 and CZ.02.1.01/0.0/0.0/17_049/0008422; France - Centre de Calcul IN2P3/CNRS; Centre National de la Recherche Scientifique (CNRS) ; Conseil Regional IledeFrance; Departement Physique Nucleaire et Corpusculaire (PNCIN2P3/CNRS) ; Departement Sciences de l'Univers (SDUINSU/CNRS) ; Institut Lagrange de Paris (ILP) Grant No. LABEX ANR-10-LABX-63 within the Investissements d'Avenir Programme Grant No. ANR11IDEX000402; Germany - Bundesministerium fur Bildung und Forschung (BMBF) ; Deutsche Forschungsgemeinschaft (DFG) ; Finanzministerium BadenWurttemberg; Helmholtz Alliance for Astroparticle Physics (HAP) ; Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF) ; Min-isterium fur Innovation, Wissenschaft und Forschung des Landes NordrheinWestfalen; Minis-terium fur Wissenschaft, Forschung und Kunst des Landes BadenWurttemberg; Italy - Isti-tuto Nazionale di Fisica Nucleare (INFN) ; Istituto Nazionale di Astrofisica (INAF) ; Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR) ; CETEMPS Center of Excellence; Minis-tero degli Affari Esteri (MAE) ; Mexico - Consejo Nacional de Ciencia y Tecnologia (CONACYT) No. 167733; Universidad Nacional Autonoma de Mexico (UNAM) ; PAPIIT DGAPAUNAM; The Netherlands - Ministry of Education, Culture and Science; Netherlands Organisation for Sci-entific Research (NWO) ; Dutch national e-infrastructure with the support of SURF Cooperative; Poland-Ministry of Science and Higher Education, grant No. DIR/WK/2018/11; National Sci-ence Centre, Grants No. 2013/08/M/ST9/00322, No. 2016/23/B/ST9/01635 and No. HARMONIA 5-2013/10/M/ST9/00062, UMO2016/22/M/ST9/00198; Portugal - Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE) ; Romania - Romanian Ministry of Education and Research, the Program Nucleu within MCI (PN19150201/16N/2019 and PN19060102) and project PNIIIP11.2PCCDI20170839/19PCCDI/2018 within PNCDI III; Slovenia - Slovenian Research Agency, grants P10031, P10385, I00033, N10111; Spain - Ministerio de Economia, Industria y Competitividad (FPA2017-85114-P and PID2019104676GBC32, Xunta de Galicia (ED431C 2017/07) , Junta de Andalucia (SOMM17/6104/UGR, P18-FR-4314) Feder Funds, RENATA Red Nacional Tematica de Astroparticulas (FPA2015-68783-REDT) and Maria de Maeztu Unit of Excel-lence (MDM20160692) ; U.S.A. - Department of Energy, Contracts No. DEAC0207CH11359, No. DEFR0204ER41300, No. DE-FG02-99ER41107 and No. DESC0011689; National Sci-ence Foundation, Grant No. 0450696; The Grainger Foundation; Marie CurieIRSES/EPLANET; European Particle Physics Latin American Network; and UNESCO.FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operation of a robotic telescope for such a purpose and their implementation within the FRAM system.Argentina - Comision Nacional de Energia AtomicaANPCyTConsejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Australian Research CouncilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF)Financiadora de Inovacao e Pesquisa (Finep)Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2019/101512 2010/07359-6 1999/054043Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC)Czech Republic GovernmentMinistry of Education, Youth & Sports - Czech Republic LTT18004 LM2015038 LM2018102 CZ.02.1.01/0.0/0.0/16_013/0001402 CZ.02.1.01/0.0/0.0/18_046/0016010 CZ.02.1.01/0.0/0.0/17_049/0008422 IN2P3/CNRSCentre National de la Recherche Scientifique (CNRS)Region Ile-de-France PNCIN2P3/CNRSInstitut Lagrange de Paris (ILP)LABEX ANR-10-LABX-63 ANR11IDEX000402Federal Ministry of Education & Research (BMBF)German Research Foundation (DFG)Helmholtz Alliance for Astroparticle Physics (HAP)Helmholtz AssociationMin-isterium fur Innovation, Wissenschaft und Forschung des Landes NordrheinWestfalenMinis-terium fur Wissenschaft, Forschung und Kunst des Landes BadenWurttemberg; Italy - Isti-tuto Nazionale di Fisica Nucleare (INFN)Ministry of Education, Universities and Research (MIUR)CETEMPS Center of ExcellenceConsejo Nacional de Ciencia y Tecnologia (CONACyT) 167733Universidad Nacional Autonoma de MexicoPrograma de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) Universidad Nacional Autonoma de MexicoNetherlands Organization for Scientific Research (NWO) DIR/WK/2018/11National Science Centre, Poland 2013/08/M/ST9/00322 2016/23/B/ST9/01635 HARMONIA 5-2013/10/M/ST9/00062 UMO2016/22/M/ST9/00198Portugal - Portuguese national fundsFEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE)Romania - Romanian Ministry of Education and ResearchProgram Nucleu within MCI PN19150201/16N/2019 PN19060102 PNIIIP11.2PCCDI20170839/19PCCDI/2018Slovenian Research Agency - Slovenia P10031 P10385 I00033 N10111 FPA2017-85114-P PID2019104676GBC32Xunta de Galicia European Commission ED431C 2017/07Junta de Andalucia SOMM17/6104/UGR P18-FR-4314European CommissionRENATA Red Nacional Tematica de Astroparticulas FPA2015-68783-REDTMaria de Maeztu Unit of Excel-lence MDM20160692United States Department of Energy (DOE) DEAC0207CH11359 DEFR0204ER41300 DE-FG02-99ER41107 DESC0011689National Science Foundation (NSF) 0450696Grainger FoundationEuropean Particle Physics Latin American NetworkUNESC