Catálogo de publicaciones - revistas
Título de Acceso Abierto
The Astrophysical Journal (ApJ)
Resumen/Descripción – provisto por la editorial en inglés
The Astrophysical Journal is an open access journal devoted to recent developments, discoveries, and theories in astronomy and astrophysics. Publications in ApJ constitute significant new research that is directly relevant to astrophysical applications, whether based on observational results or on theoretical insights or modeling.Palabras clave – provistas por la editorial
astronomy; astrophysics
Disponibilidad
| Institución detectada | Período | Navegá | Descargá | Solicitá |
|---|---|---|---|---|
| No detectada | desde jul. 1995 / hasta dic. 2023 | IOPScience |
Información
Tipo de recurso:
revistas
ISSN impreso
0004-637X
ISSN electrónico
1538-4357
Editor responsable
American Astronomical Society (AAS)
Idiomas de la publicación
- inglés
País de edición
Reino Unido
Información sobre licencias CC
Cobertura temática
Tabla de contenidos
Subarcsecond Imaging of the Complex Organic Chemistry in Massive Star-forming Region G10.6-0.4
Charles J. Law
; Qizhou Zhang; Karin I. Öberg; Roberto Galván-Madrid; Eric Keto; Hauyu Baobab Liu; Paul T. P. Ho
<jats:title>Abstract</jats:title> <jats:p>Massive star-forming regions exhibit an extremely rich and diverse chemistry, which in principle provides a wealth of molecular probes, as well as laboratories for interstellar prebiotic chemistry. Since the chemical structure of these sources displays substantial spatial variation among species on small scales (≲10<jats:sup>4</jats:sup> au), high-angular-resolution observations are needed to connect chemical structures to local environments and inform astrochemical models of massive star formation. To address this, we present ALMA 1.3 mm observations toward OB cluster-forming region G10.6-0.4 (hereafter “G10.6”) at a resolution of 014 (700 au). We find highly structured emission from complex organic molecules (COMs) throughout the central 20,000 au, including two hot molecular cores and several shells or filaments. We present spatially resolved maps of rotational temperature and column density for a large sample of COMs and warm gas tracers. These maps reveal a range of gas substructure in both O- and N-bearing species. We identify several spatial correlations that can be explained by existing models for the formation of COMs, including NH<jats:sub>2</jats:sub>CHO/HNCO and CH<jats:sub>3</jats:sub>OCHO/CH<jats:sub>3</jats:sub>OCH<jats:sub>3</jats:sub>, but also observe unexpected distributions and correlations that suggest that our current understanding of COM formation is far from complete. Importantly, complex chemistry is observed throughout G10.6, rather than being confined to hot cores. The COM composition appears to be different in the cores compared to the more extended structures, which illustrates the importance of high-spatial-resolution observations of molecular gas in elucidating the physical and chemical processes associated with massive star formation.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 214
Time and Charge-sign Dependence of the Heliospheric Modulation of Cosmic Rays
O. P. M. Aslam; D. Bisschoff; M. D. Ngobeni; M. S. Potgieter; R. Munini; M. Boezio; V. V. Mikhailov
<jats:title>Abstract</jats:title> <jats:p>Simultaneous and continuous observations of galactic cosmic-ray electrons (<jats:italic>e</jats:italic> <jats:sup>−</jats:sup>) and positrons (<jats:italic>e</jats:italic> <jats:sup>+</jats:sup>) from the PAMELA and AMS02 space experiments are most suitable for numerical modeling studies of the heliospheric modulation of these particles below 50 GeV. A well-established comprehensive three-dimensional modulation model is applied to compute full spectra for <jats:italic>e</jats:italic> <jats:sup>−</jats:sup> and <jats:italic>e</jats:italic> <jats:sup>+</jats:sup> with the purpose of reproducing the observed ratio <jats:italic>e</jats:italic> <jats:sup>+</jats:sup>/<jats:italic>e</jats:italic> <jats:sup>−</jats:sup> for a period that covers the previous long and unusual deep solar minimum activity and the recent maximum activity phase, including the polarity reversal of the solar magnetic field. For this purpose, the very local interstellar spectra for these particles were established first. Our study is focused on how the main modulation processes, including particle drifts, and other parameters, such as the three major diffusion coefficients, evolved and how the corresponding charge-sign dependent modulation subsequently occurred. The end result of our effort is the detailed reproduction of <jats:italic>e</jats:italic> <jats:sup>+</jats:sup>/<jats:italic>e</jats:italic> <jats:sup>−</jats:sup> from 2006 to 2015, displaying both qualitative and quantitative agreement with the main observed features. Particularly, we determine how much particle drift is needed to explain the time dependence exhibited by the observed <jats:italic>e</jats:italic> <jats:sup>+</jats:sup>/<jats:italic>e</jats:italic> <jats:sup>−</jats:sup> during each solar activity phase, especially during the polarity reversal phase, when no well-defined magnetic polarity was found.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 215
Boyajian’s Star B: The Co-moving Companion to KIC 8462852 A
Logan A. Pearce; Adam L. Kraus; Trent J. Dupuy; Andrew W. Mann; Daniel Huber
<jats:title>Abstract</jats:title> <jats:p>The light curve of KIC 8462852, aka Boyajian’s Star, undergoes deep dips the origin of which remains unclear. A faint star ≈2″ to the east was discovered in Keck/NIRC2 imaging in Boyajian et al., but its status as a binary, and possible contribution to the observed variability, was unclear. Here, we use three epochs of Keck/NIRC2 imaging, spanning 5 yr, in JHK near-infrared bands to obtain 1 mas precision astrometry. We show that the two objects exhibit common proper motion, measure a relative velocity of <jats:italic>μ</jats:italic> = 0.14 ± 0.44 mas yr<jats:sup>−1</jats:sup> (<jats:italic>μ</jats:italic> = 0.30 ± 0.93 km s<jats:sup>−1</jats:sup>) and conclude that they are a binary pair at 880 ± 10 au projected separation. There is marginal detection of possible orbital motion, but our astrometry is insufficient to characterize the orbit. We show that two other point sources are not associated with KIC 8462852. We recommend that attempts to model KIC 8462852 A’s light curve should revisit the possibility that the bound stellar companion may play a role in causing the irregular brightness variations, for example, through disruption of the orbits of bodies around the primary due to long-term orbital evolution of the binary orbit.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 216
Black Hole Glimmer Signatures of Mass, Spin, and Inclination
George N. Wong
<jats:title>Abstract</jats:title> <jats:p>Gravitational lensing near a black hole is strong enough that light rays can circle the event horizon multiple times. Photons emitted in multiple directions at a single event, perhaps because of localized, impulsive heating of accreting plasma, take multiple paths to a distant observer. In the Kerr geometry, each path is associated with a distinct light travel time and a distinct arrival location in the image plane, producing black hole glimmer. This sequence of arrival times and locations uniquely encodes the mass and spin of the black hole and can be understood in terms of properties of bound photon orbits. We provide a geometrically motivated treatment of Kerr glimmer and evaluate it numerically for simple hot-spot models to show that glimmer can be measured in a finite-resolution observation. We discuss potential measurement methods and implications for tests of the Kerr hypothesis.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 217
A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo
B. P. Abbott; R. Abbott; T. D. Abbott; S. Abraham; F. Acernese; K. Ackley; C. Adams; R. X. Adhikari; V. B. Adya; C. Affeldt; M. Agathos; K. Agatsuma; N. Aggarwal; O. D. Aguiar; L. Aiello; A. Ain; P. Ajith; G. Allen; A. Allocca; M. A. Aloy; P. A. Altin; A. Amato; S. Anand; A. Ananyeva; S. B. Anderson; W. G. Anderson; S. V. Angelova; S. Antier; S. Appert; K. Arai; M. C. Araya; J. S. Areeda; M. Arène; N. Arnaud; S. M. Aronson; K. G. Arun; S. Ascenzi; G. Ashton; S. M. Aston; P. Astone; F. Aubin; P. Aufmuth; K. AultONeal; C. Austin; V. Avendano; A. Avila-Alvarez; S. Babak; P. Bacon; F. Badaracco; M. K. M. Bader; S. Bae; J. Baird; P. T. Baker; F. Baldaccini; G. Ballardin; S. W. Ballmer; A. Bals; S. Banagiri; J. C. Barayoga; C. Barbieri; S. E. Barclay; B. C. Barish; D. Barker; K. Barkett; S. Barnum; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; D. Barta; J. Bartlett; I. Bartos; R. Bassiri; A. Basti; M. Bawaj; J. C. Bayley; M. Bazzan; B. Bécsy; M. Bejger; I. Belahcene; A. S. Bell; D. Beniwal; M. G. Benjamin; B. K. Berger; G. Bergmann; S. Bernuzzi; C. P. L. Berry; D. Bersanetti; A. Bertolini; J. Betzwieser; R. Bhandare; J. Bidler; E. Biggs; I. A. Bilenko; S. A. Bilgili; G. Billingsley; R. Birney; O. Birnholtz; S. Biscans; M. Bischi; S. Biscoveanu; A. Bisht; M. Bitossi; M. A. Bizouard; J. K. Blackburn; J. Blackman; C. D. Blair; D. G. Blair; R. M. Blair; S. Bloemen; F. Bobba; N. Bode; M. Boer; Y. Boetzel; G. Bogaert; F. Bondu; R. Bonnand; P. Booker; B. A. Boom; R. Bork; V. Boschi; S. Bose; V. Bossilkov; J. Bosveld; Y. Bouffanais; A. Bozzi; C. Bradaschia; P. R. Brady; A. Bramley; M. Branchesi; J. E. Brau; M. Breschi; T. Briant; J. H. Briggs; F. Brighenti; A. Brillet; M. Brinkmann; P. Brockill; A. F. Brooks; J. Brooks; D. D. Brown; S. Brunett; A. Buikema; T. Bulik; H. J. Bulten; A. Buonanno; D. Buskulic; C. Buy; R. L. Byer; M. Cabero; L. Cadonati; G. Cagnoli; C. Cahillane; J. Calderón Bustillo; T. A. Callister; E. Calloni; J. B. Camp; W. A. Campbell; M. Canepa; K. C. Cannon; H. Cao; J. Cao; G. Carapella; F. Carbognani; S. Caride; M. F. Carney; G. Carullo; J. Casanueva Diaz; C. Casentini; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; G. Cella; P. Cerdá-Durán; E. Cesarini; O. Chaibi; K. Chakravarti; S. J. Chamberlin; M. Chan; S. Chao; P. Charlton; E. A. Chase; E. Chassande-Mottin; D. Chatterjee; M. Chaturvedi; B. D. Cheeseboro; H. Y. Chen; X. Chen; Y. Chen; H.-P. Cheng; C. K. Cheong; H. Y. Chia; F. Chiadini; A. Chincarini; A. Chiummo; G. Cho; H. S. Cho; M. Cho; N. Christensen; Q. Chu; S. Chua; K. W. Chung; S. Chung; G. Ciani; M. Cieślar; A. A. Ciobanu; R. Ciolfi; F. Cipriano; A. Cirone; F. Clara; J. A. Clark; P. Clearwater; F. Cleva; E. Coccia; P.-F. Cohadon; D. Cohen; M. Colleoni; C. G. Collette; C. Collins; M. Colpi; L. R. Cominsky; M. Constancio; L. Conti; S. J. Cooper; P. Corban; T. R. Corbitt; I. Cordero-Carrión; S. Corezzi; K. R. Corley; N. Cornish; D. Corre; A. Corsi; S. Cortese; C. A. Costa; R. Cotesta; M. W. Coughlin; S. B. Coughlin; J.-P. Coulon; S. T. Countryman; P. Couvares; P. B. Covas; E. E. Cowan; D. M. Coward; M. J. Cowart; D. C. Coyne; R. Coyne; J. D. E. Creighton; T. D. Creighton; J. Cripe; M. Croquette; S. G. Crowder; T. J. Cullen; A. Cumming; L. Cunningham; E. Cuoco; T. Dal Canton; G. Dálya; B. D’Angelo; S. L. Danilishin; S. D’Antonio; K. Danzmann; A. Dasgupta; C. F. Da Silva Costa; L. E. H. Datrier; V. Dattilo; I. Dave; M. Davier; D. Davis; E. J. Daw; D. DeBra; M. Deenadayalan; J. Degallaix; M. De Laurentis; S. Deléglise; W. Del Pozzo; L. M. DeMarchi; N. Demos; T. Dent; R. De Pietri; R. De Rosa; C. De Rossi; R. DeSalvo; O. de Varona; S. Dhurandhar; M. C. Díaz; T. Dietrich; L. Di Fiore; C. DiFronzo; C. Di Giorgio; F. Di Giovanni; M. Di Giovanni; T. Di Girolamo; A. Di Lieto; B. Ding; S. Di Pace; I. Di Palma; F. Di Renzo; A. K. Divakarla; A. Dmitriev; Z. Doctor; F. Donovan; K. L. Dooley; S. Doravari; I. Dorrington; T. P. Downes; M. Drago; J. C. Driggers; Z. Du; J.-G. Ducoin; P. Dupej; O. Durante; S. E. Dwyer; P. J. Easter; G. Eddolls; T. B. Edo; A. Effler; P. Ehrens; J. Eichholz; S. S. Eikenberry; M. Eisenmann; R. A. Eisenstein; L. Errico; R. C. Essick; H. Estelles; D. Estevez; Z. B. Etienne; T. Etzel; M. Evans; T. M. Evans; V. Fafone; S. Fairhurst; X. Fan; S. Farinon; B. Farr; W. M. Farr; E. J. Fauchon-Jones; M. Favata; M. Fays; M. Fazio; C. Fee; J. Feicht; M. M. Fejer; F. Feng; A. Fernandez-Galiana; I. Ferrante; E. C. Ferreira; T. A. Ferreira; F. Fidecaro; I. Fiori; D. Fiorucci; M. Fishbach; R. P. Fisher; J. M. Fishner; R. Fittipaldi; M. Fitz-Axen; V. Fiumara; R. Flaminio; M. Fletcher; E. Floden; E. Flynn; H. Fong; J. A. Font; P. W. F. Forsyth; J.-D. Fournier; Francisco Hernandez Vivanco; S. Frasca; F. Frasconi; Z. Frei; A. Freise; R. Frey; V. Frey; P. Fritschel; V. V. Frolov; G. Fronzè; P. Fulda; M. Fyffe; H. A. Gabbard; B. U. Gadre; S. M. Gaebel; J. R. Gair; L. Gammaitoni; S. G. Gaonkar; C. García-Quirós; F. Garufi; B. Gateley; S. Gaudio; G. Gaur; V. Gayathri; G. Gemme; E. Genin; A. Gennai; D. George; J. George; L. Gergely; S. Ghonge; Abhirup Ghosh; Archisman Ghosh; S. Ghosh; B. Giacomazzo; J. A. Giaime; K. D. Giardina; D. R. Gibson; K. Gill; L. Glover; J. Gniesmer; P. Godwin; E. Goetz; R. Goetz; B. Goncharov; G. González; J. M. Gonzalez Castro; A. Gopakumar; S. E. Gossan; M. Gosselin; R. Gouaty; B. Grace; A. Grado; M. Granata; A. Grant; S. Gras; P. Grassia; C. Gray; R. Gray; G. Greco; A. C. Green; R. Green; E. M. Gretarsson; A. Grimaldi; S. J. Grimm; P. Groot; H. Grote; S. Grunewald; P. Gruning; G. M. Guidi; H. K. Gulati; Y. Guo; A. Gupta; Anchal Gupta; P. Gupta; E. K. Gustafson; R. Gustafson; L. Haegel; O. Halim; B. R. Hall; E. D. Hall; E. Z. Hamilton; G. Hammond; M. Haney; M. M. Hanke; J. Hanks; C. Hanna; M. D. Hannam; O. A. Hannuksela; T. J. Hansen; J. Hanson; T. Harder; T. Hardwick; K. Haris; J. Harms; G. M. Harry; I. W. Harry; R. K. Hasskew; C. J. Haster; K. Haughian; F. J. Hayes; J. Healy; A. Heidmann; M. C. Heintze; H. Heitmann; F. Hellman; P. Hello; G. Hemming; M. Hendry; I. S. Heng; J. Hennig; M. Heurs; S. Hild; T. Hinderer; S. Hochheim; D. Hofman; A. M. Holgado; N. A. Holland; K. Holt; D. E. Holz; P. Hopkins; C. Horst; J. Hough; E. J. Howell; C. G. Hoy; Y. Huang; M. T. Hübner; E. A. Huerta; D. Huet; B. Hughey; V. Hui; S. Husa; S. H. Huttner; T. Huynh-Dinh; B. Idzkowski; A. Iess; H. Inchauspe; C. Ingram; R. Inta; G. Intini; B. Irwin; H. N. Isa; J.-M. Isac; M. Isi; B. R. Iyer; T. Jacqmin; S. J. Jadhav; K. Jani; N. N. Janthalur; P. Jaranowski; D. Jariwala; A. C. Jenkins; J. Jiang; D. S. Johnson; A. W. Jones; D. I. Jones; J. D. Jones; R. Jones; R. J. G. Jonker; L. Ju; J. Junker; C. V. Kalaghatgi; V. Kalogera; B. Kamai; S. Kandhasamy; G. Kang; J. B. Kanner; S. J. Kapadia; C. Karathanasis; S. Karki; R. Kashyap; M. Kasprzack; S. Katsanevas; E. Katsavounidis; W. Katzman; S. Kaufer; K. Kawabe; N. V. Keerthana; F. Kéfélian; D. Keitel; R. Kennedy; J. S. Key; F. Y. Khalili; I. Khan; S. Khan; E. A. Khazanov; N. Khetan; M. Khursheed; N. Kijbunchoo; Chunglee Kim; J. C. Kim; K. Kim; W. Kim; W. S. Kim; Y.-M. Kim; C. Kimball; P. J. King; M. Kinley-Hanlon; R. Kirchhoff; J. S. Kissel; L. Kleybolte; J. H. Klika; S. Klimenko; T. D. Knowles; P. Koch; S. M. Koehlenbeck; G. Koekoek; S. Koley; V. Kondrashov; A. Kontos; N. Koper; M. Korobko; W. Z. Korth; M. Kovalam; D. B. Kozak; C. Krämer; V. Kringel; N. Krishnendu; A. Królak; N. Krupinski; G. Kuehn; A. Kumar; P. Kumar; Rahul Kumar; Rakesh Kumar; L. Kuo; A. Kutynia; S. Kwang; B. D. Lackey; D. Laghi; K. H. Lai; T. L. Lam; M. Landry; B. B. Lane; R. N. Lang; J. Lange; B. Lantz; R. K. Lanza; A. Lartaux-Vollard; P. D. Lasky; M. Laxen; A. Lazzarini; C. Lazzaro; P. Leaci; S. Leavey; Y. K. Lecoeuche; C. H. Lee; H. K. Lee; H. M. Lee; H. W. Lee; J. Lee; K. Lee; J. Lehmann; A. K. Lenon; N. Leroy; N. Letendre; Y. Levin; A. Li; J. Li; K. J. L. Li; T. G. F. Li; X. Li; F. Lin; F. Linde; S. D. Linker; T. B. Littenberg; J. Liu; X. Liu; M. Llorens-Monteagudo; R. K. L. Lo; L. T. London; A. Longo; M. Lorenzini; V. Loriette; M. Lormand; G. Losurdo; J. D. Lough; C. O. Lousto; G. Lovelace; M. E. Lower; H. Lück; D. Lumaca; A. P. Lundgren; R. Lynch; Y. Ma; R. Macas; S. Macfoy; M. MacInnis; D. M. Macleod; A. Macquet; I. Magaña Hernandez; F. Magaña-Sandoval; R. M. Magee; E. Majorana; I. Maksimovic; A. Malik; N. Man; V. Mandic; V. Mangano; G. L. Mansell; M. Manske; M. Mantovani; M. Mapelli; F. Marchesoni; F. Marion; S. Márka; Z. Márka; C. Markakis; A. S. Markosyan; A. Markowitz; E. Maros; A. Marquina; S. Marsat; F. Martelli; I. W. Martin; R. M. Martin; V. Martinez; D. V. Martynov; H. Masalehdan; K. Mason; E. Massera; A. Masserot; T. J. Massinger; M. Masso-Reid; S. Mastrogiovanni; A. Matas; F. Matichard; L. Matone; N. Mavalvala; J. J. McCann; R. McCarthy; D. E. McClelland; S. McCormick; L. McCuller; S. C. McGuire; C. McIsaac; J. McIver; D. J. McManus; T. McRae; S. T. McWilliams; D. Meacher; G. D. Meadors; M. Mehmet; A. K. Mehta; J. Meidam; E. Mejuto Villa; A. Melatos; G. Mendell; R. A. Mercer; L. Mereni; K. Merfeld; E. L. Merilh; M. Merzougui; S. Meshkov; C. Messenger; C. Messick; F. Messina; R. Metzdorff; P. M. Meyers; F. Meylahn; A. Miani; H. Miao; C. Michel; H. Middleton; L. Milano; A. L. Miller; M. Millhouse; J. C. Mills; M. C. Milovich-Goff; O. Minazzoli; Y. Minenkov; A. Mishkin; C. Mishra; T. Mistry; S. Mitra; V. P. Mitrofanov; G. Mitselmakher; R. Mittleman; G. Mo; D. Moffa; K. Mogushi; S. R. P. Mohapatra; M. Molina-Ruiz; M. Mondin; M. Montani; C. J. Moore; D. Moraru; F. Morawski; G. Moreno; S. Morisaki; B. Mours; C. M. Mow-Lowry; F. Muciaccia; Arunava Mukherjee; D. Mukherjee; S. Mukherjee; Subroto Mukherjee; N. Mukund; A. Mullavey; J. Munch; E. A. Muñiz; M. Muratore; P. G. Murray; A. Nagar; I. Nardecchia; L. Naticchioni; R. K. Nayak; B. F. Neil; J. Neilson; G. Nelemans; T. J. N. Nelson; M. Nery; A. Neunzert; L. Nevin; K. Y. Ng; S. Ng; C. Nguyen; P. Nguyen; D. Nichols; S. A. Nichols; S. Nissanke; F. Nocera; C. North; L. K. Nuttall; M. Obergaulinger; J. Oberling; B. D. O’Brien; G. Oganesyan; G. H. Ogin; J. J. Oh; S. H. Oh; F. Ohme; H. Ohta; M. A. Okada; M. Oliver; P. Oppermann; Richard J. Oram; B. O’Reilly; R. G. Ormiston; L. F. Ortega; R. O’Shaughnessy; S. Ossokine; D. J. Ottaway; H. Overmier; B. J. Owen; A. E. Pace; G. Pagano; M. A. Page; G. Pagliaroli; A. Pai; S. A. Pai; J. R. Palamos; O. Palashov; C. Palomba; H. Pan; P. K. Panda; P. T. H. Pang; C. Pankow; F. Pannarale; B. C. Pant; F. Paoletti; A. Paoli; A. Parida; W. Parker; D. Pascucci; A. Pasqualetti; R. Passaquieti; D. Passuello; M. Patil; B. Patricelli; E. Payne; B. L. Pearlstone; T. C. Pechsiri; A. J. Pedersen; M. Pedraza; R. Pedurand; A. Pele; S. Penn; A. Perego; C. J. Perez; C. Périgois; A. Perreca; J. Petermann; H. P. Pfeiffer; M. Phelps; K. S. Phukon; O. J. Piccinni; M. Pichot; F. Piergiovanni; V. Pierro; G. Pillant; L. Pinard; I. M. Pinto; M. Pirello; M. Pitkin; W. Plastino; R. Poggiani; D. Y. T. Pong; S. Ponrathnam; P. Popolizio; E. K. Porter; J. Powell; A. K. Prajapati; J. Prasad; K. Prasai; R. Prasanna; G. Pratten; T. Prestegard; M. Principe; G. A. Prodi; L. Prokhorov; M. Punturo; P. Puppo; M. Pürrer; H. Qi; V. Quetschke; P. J. Quinonez; F. J. Raab; G. Raaijmakers; H. Radkins; N. Radulesco; P. Raffai; S. Raja; C. Rajan; B. Rajbhandari; M. Rakhmanov; K. E. Ramirez; A. Ramos-Buades; Javed Rana; K. Rao; P. Rapagnani; V. Raymond; M. Razzano; J. Read; T. Regimbau; L. Rei; S. Reid; D. H. Reitze; P. Rettegno; F. Ricci; C. J. Richardson; J. W. Richardson; P. M. Ricker; G. Riemenschneider; K. Riles; M. Rizzo; N. A. Robertson; F. Robinet; A. Rocchi; L. Rolland; J. G. Rollins; V. J. Roma; M. Romanelli; J. Romano; R. Romano; C. L. Romel; J. H. Romie; C. A. Rose; D. Rose; K. Rose; D. Rosińska; S. G. Rosofsky; M. P. Ross; S. Rowan; A. Rüdiger; P. Ruggi; G. Rutins; K. Ryan; S. Sachdev; T. Sadecki; M. Sakellariadou; O. S. Salafia; L. Salconi; M. Saleem; A. Samajdar; L. Sammut; E. J. Sanchez; L. E. Sanchez; N. Sanchis-Gual; J. R. Sanders; K. A. Santiago; E. Santos; N. Sarin; B. Sassolas; B. S. Sathyaprakash; O. Sauter; R. L. Savage; P. Schale; M. Scheel; J. Scheuer; P. Schmidt; R. Schnabel; R. M. S. Schofield; A. Schönbeck; E. Schreiber; B. W. Schulte; B. F. Schutz; J. Scott; S. M. Scott; E. Seidel; D. Sellers; A. S. Sengupta; N. Sennett; D. Sentenac; V. Sequino; A. Sergeev; Y. Setyawati; D. A. Shaddock; T. Shaffer; M. S. Shahriar; M. B. Shaner; A. Sharma; P. Sharma; P. Shawhan; H. Shen; R. Shink; D. H. Shoemaker; D. M. Shoemaker; K. Shukla; S. ShyamSundar; K. Siellez; M. Sieniawska; D. Sigg; L. P. Singer; D. Singh; N. Singh; A. Singhal; A. M. Sintes; S. Sitmukhambetov; V. Skliris; B. J. J. Slagmolen; T. J. Slaven-Blair; J. R. Smith; R. J. E. Smith; S. Somala; E. J. Son; S. Soni; B. Sorazu; F. Sorrentino; T. Souradeep; E. Sowell; A. P. Spencer; M. Spera; A. K. Srivastava; V. Srivastava; K. Staats; C. Stachie; M. Standke; D. A. Steer; M. Steinke; J. Steinlechner; S. Steinlechner; D. Steinmeyer; S. P. Stevenson; D. Stocks; R. Stone; D. J. Stops; K. A. Strain; G. Stratta; S. E. Strigin; A. Strunk; R. Sturani; A. L. Stuver; V. Sudhir; T. Z. Summerscales; L. Sun; S. Sunil; A. Sur; J. Suresh; P. J. Sutton; B. L. Swinkels; M. J. Szczepańczyk; M. Tacca; S. C. Tait; C. Talbot; D. B. Tanner; D. Tao; M. Tápai; A. Tapia; J. D. Tasson; R. Taylor; R. Tenorio; L. Terkowski; M. Thomas; P. Thomas; S. R. Thondapu; K. A. Thorne; E. Thrane; Shubhanshu Tiwari; Srishti Tiwari; V. Tiwari; K. Toland; M. Tonelli; Z. Tornasi; A. Torres-Forné; C. I. Torrie; D. Töyrä; F. Travasso; G. Traylor; M. C. Tringali; A. Tripathee; A. Trovato; L. Trozzo; K. W. Tsang; M. Tse; R. Tso; L. Tsukada; D. Tsuna; T. Tsutsui; D. Tuyenbayev; K. Ueno; D. Ugolini; C. S. Unnikrishnan; A. L. Urban; S. A. Usman; H. Vahlbruch; G. Vajente; G. Valdes; M. Valentini; N. van Bakel; M. van Beuzekom; J. F. J. van den Brand; C. Van Den Broeck; D. C. Vander-Hyde; L. van der Schaaf; J. V. VanHeijningen; A. A. van Veggel; M. Vardaro; V. Varma; S. Vass; M. Vasúth; A. Vecchio; G. Vedovato; J. Veitch; P. J. Veitch; K. Venkateswara; G. Venugopalan; D. Verkindt; F. Vetrano; A. Viceré; A. D. Viets; S. Vinciguerra; D. J. Vine; J.-Y. Vinet; S. Vitale; T. Vo; H. Vocca; C. Vorvick; S. P. Vyatchanin; A. R. Wade; L. E. Wade; M. Wade; R. Walet; M. Walker; L. Wallace; S. Walsh; H. Wang; J. Z. Wang; S. Wang; W. H. Wang; Y. F. Wang; R. L. Ward; Z. A. Warden; J. Warner; M. Was; J. Watchi; B. Weaver; L.-W. Wei; M. Weinert; A. J. Weinstein; R. Weiss; F. Wellmann; L. Wen; E. K. Wessel; P. Weßels; J. W. Westhouse; K. Wette; J. T. Whelan; B. F. Whiting; C. Whittle; D. M. Wilken; D. Williams; A. R. Williamson; J. L. Willis; B. Willke; W. Winkler; C. C. Wipf; H. Wittel; G. Woan; J. Woehler; J. K. Wofford; J. L. Wright; D. S. Wu; D. M. Wysocki; S. Xiao; R. Xu; H. Yamamoto; C. C. Yancey; L. Yang; Y. Yang; Z. Yang; M. J. Yap; M. Yazback; D. W. Yeeles; Hang Yu; Haocun Yu; S. H. R. Yuen; A. K. Zadrożny; A. Zadrożny; M. Zanolin; T. Zelenova; J.-P. Zendri; M. Zevin; J. Zhang; L. Zhang; T. Zhang; C. Zhao; G. Zhao; M. Zhou; Z. Zhou; X. J. Zhu; A. B. Zimmerman; M. E. Zucker; J. Zweizig
<jats:title>Abstract</jats:title> <jats:p>This paper presents the gravitational-wave measurement of the Hubble constant (<jats:italic>H</jats:italic> <jats:sub>0</jats:sub>) using the detections from the first and second observing runs of the Advanced LIGO and Virgo detector network. The presence of the transient electromagnetic counterpart of the binary neutron star GW170817 led to the first standard-siren measurement of <jats:italic>H</jats:italic> <jats:sub>0</jats:sub>. Here we additionally use binary black hole detections in conjunction with galaxy catalogs and report a joint measurement. Our updated measurement is <jats:italic>H</jats:italic> <jats:sub>0</jats:sub> = <jats:inline-formula> <jats:tex-math> <?CDATA ${69}_{-8}^{+16}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>69</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>16</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabdcb7ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> km s<jats:sup>−1</jats:sup> Mpc<jats:sup>−1</jats:sup> (68.3% of the highest density posterior interval with a flat-in-log prior) which is an improvement by a factor of 1.04 (about 4%) over the GW170817-only value of <jats:inline-formula> <jats:tex-math> <?CDATA ${69}_{-8}^{+17}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>69</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>17</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabdcb7ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> km s<jats:sup>−1</jats:sup> Mpc<jats:sup>−1</jats:sup>. A significant additional contribution currently comes from GW170814, a loud and well-localized detection from a part of the sky thoroughly covered by the Dark Energy Survey. With numerous detections anticipated over the upcoming years, an exhaustive understanding of other systematic effects are also going to become increasingly important. These results establish the path to cosmology using gravitational-wave observations with and without transient electromagnetic counterparts.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 218
A Study in Frequency-dependent Effects on Precision Pulsar Timing Parameters with the Pulsar Signal Simulator
B. J. Shapiro-Albert; J. S. Hazboun; M. A. McLaughlin; M. T. Lam
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 219
Two-point Statistics without Bins: A Continuous-function Generalization of the Correlation Function Estimator for Large-scale Structure
Kate Storey-Fisher; David W. Hogg
<jats:title>Abstract</jats:title> <jats:p>The two-point correlation function (2pcf) is the key statistic in structure formation; it measures the clustering of galaxies or other density field tracers. Estimators of the 2pcf, including the standard Landy–Szalay (LS) estimator, evaluate the 2pcf in hard-edged separation bins, which is scientifically inappropriate and results in a poor trade-off between bias and variance. We present a new 2pcf estimator, the Continuous-Function Estimator, which generalizes LS to a continuous representation and obviates binning in separation or any other pair property. Our estimator, inspired by the mathematics of least-squares fitting, replaces binned pair counts with projections onto basis functions; it outputs the best linear combination of basis functions to describe the 2pcf. The choice of basis can take into account the expected form of the 2pcf, as well as its dependence on pair properties other than separation. We show that the Continuous-Function Estimator with a cubic-spline basis better represents the shape of the 2pcf compared to LS. We also estimate directly the baryon acoustic scale, using a small number of physically motivated basis functions. Critically, this leads to a reduction in the number of mock catalogs required for covariance estimation, which is currently the limiting step in many 2pcf analyses. We discuss further applications of the Continuous-Function Estimator, including determination of the dependence of clustering on galaxy properties and searches for potential inhomogeneities or anisotropies in large-scale structure.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 220
Erratum: “The Energy-dependent γ-Ray Morphology of the Crab Nebula Observed with the Fermi Large Area Telescope” (2019, ApJ, 875, 123)
Paul K. H. Yeung; Dieter Horns
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 221
Hubble Space Telescope Observations of the Old Pulsar PSR J0108–1431*
Vadim Abramkin; Yuriy Shibanov; Roberto P. Mignani; George G. Pavlov
<jats:title>Abstract</jats:title> <jats:p>We present results of optical-UV observations of the 200 Myr old rotation-powered radio pulsar J0108−1431 with the Hubble Space Telescope. We found a putative candidate for the far-UV (FUV) pulsar counterpart, with the flux density <jats:italic>f</jats:italic> <jats:sub> <jats:italic>ν</jats:italic> </jats:sub> = 9.0 ± 3.2 nJy at <jats:italic>λ</jats:italic> = 1528 Å. The pulsar was not detected, however, at longer wavelengths, with 3<jats:italic>σ</jats:italic> upper limits of 52, 37, and 87 nJy at <jats:italic>λ</jats:italic> = 4326, 3355, and 2366 Å, respectively. Assuming that the pulsar counterpart was indeed detected in FUV, and the previously reported marginal <jats:italic>U</jats:italic> and <jats:italic>B</jats:italic> detections with the Very Large Telescope were real, the optical-UV spectrum of the pulsar can be described by a power-law model with a nearly flat <jats:italic>f</jats:italic> <jats:sub> <jats:italic>ν</jats:italic> </jats:sub> spectrum. Similar to younger pulsars detected in the optical, the slope of the nonthermal spectrum steepens in the X-ray range. The pulsar’s luminosity in the 1500–6000 Å wavelength range, <jats:italic>L</jats:italic> ∼ 1.2 × 10<jats:sup>27</jats:sup>(<jats:italic>d</jats:italic>/210 pc)<jats:sup>2</jats:sup> erg s<jats:sup>−1</jats:sup>, corresponds to a high efficiency of conversion of pulsar rotation energy-loss rate <jats:inline-formula> <jats:tex-math> <?CDATA $\dot{E}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabe704ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> to the optical-UV radiation, <jats:inline-formula> <jats:tex-math> <?CDATA $\eta =L/\dot{E}\sim (1\mbox{--}6)\times {10}^{-4}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjabe704ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>, depending on somewhat uncertain values of distance and spectral slope. The brightness temperature of the bulk neutron star surface does not exceed 59,000 K (3<jats:italic>σ</jats:italic> upper bound), as seen by a distant observer. If we assume that the FUV flux is dominated by a thermal component, then the surface temperature can be in the range of 27,000–55,000 K, Requiring a heating mechanism to operate in old neutron stars.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 1
The Causes of Peripheral Coronal Loop Contraction and Disappearance Revealed in a Magnetohydrodynamic Simulation of Solar Eruption
Juntao Wang; Chaowei Jiang; Ding Yuan; Peng Zou
<jats:title>Abstract</jats:title> <jats:p>The phenomenon of peripheral coronal loop contraction during solar flares and eruptions, recently discovered in observations, has gradually drawn the attention of solar physicists. However, its underlying physical mechanism is still uncertain. One possible mechanism is Hudson’s implosion conjecture, which attributes the contraction of peripheral coronal loops to magnetic pressure reduction in the magnetic energy liberation core, while other researchers proposed alternative explanations. In previous observational studies we also note the disappearance of peripheral shrinking loops in the late phase, of which there is a lack of investigation and interpretation. In this paper, we exploit a full MHD simulation of solar eruption to study the causes of the two phenomena. It is found that the loop motion in the periphery is well correlated with magnetic energy accumulation and dissipation in the core, and the loop shrinkage is caused by a more significant reduction in magnetic pressure gradient force than in magnetic tension force, consistent with the implosion conjecture. The peripheral contracting loops in the late phase act as inflow to reconnect with central erupting structures, which destroys their identities and naturally explains their disappearance. We also propose a positive feedback between the peripheral magnetic reconnection and the central eruption.</jats:p>
Palabras clave: Space and Planetary Science; Astronomy and Astrophysics.
Pp. 2