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arXiv 2021年

作者： Miller, M.C. Lamb, F.K. Dittmann, A.J. Bogdanov, S. Arzoumanian, Z. Gendreau, K.C. Guillot, S. Ho, W.C.G. Lattimer, J.M. Loewenstein, M. Morsink, S.M. Ray, P.S. Wolff, M.T. Baker, C.L. Cazeau, T. Manthripragada, S. Markwardt, C.B. Okajima, T. Pollard, S. Cognard, I. Cromartie, H.T. Fonseca, E. Guillemot, L. Kerr, M. Parthasarathy, A. Pennucci, T.T. Ransom, S. Stairs, I. Department of Astronomy and Joint Space-Science Institute University of Maryland College ParkMD20742-2421 United States Illinois Center for Advanced Studies of the Universe and Department of Physics University of Illinois at Urbana-Champaign 1110 West Green Street UrbanaIL61801-3080 United States Department of Astronomy University of Illinois at Urbana-Champaign 1002 West Green Street UrbanaIL61801-3074 United States Columbia Astrophysics Laboratory Columbia University 550 West 120th Street New YorkNY10027 United States X-Ray Astrophysics Laboratory NASA Goddard Space Flight Center Code 662 GreenbeltMD20771 United States IRAP CNRS 9 avenue du Colonel Roche Toulouse Cedex 4F-31028 France Université de Toulouse CNES UPS-OMP ToulouseF-31028 France Department of Physics and Astronomy Haverford College 370 Lancaster Avenue HaverfordPA19041 United States Department of Physics and Astronomy Stony Brook University Stony BrookNY11794-3800 United States Department of Astronomy University of Maryland College ParkMD20742-2421 United States Center for Research and Exploration in Space Science and Technology NASA/GSFC GreenbeltMD20771 United States Department of Physics University of Alberta 4-183 CCIS EdmontonABT6G 2E1 Canada Space Science Division U.S. Naval Research Laboratory WashingtonDC20375 United States Applied Engineering and Technology NASA Goddard Space Flight Center GreenbeltMD20771 United States Instrument Systems and Technology Division NASA Goddard Space Flight Center GreenbeltMD20771 United States Astrophysics Science Division NASA Goddard Space Flight Center GreenbeltMD20771 United States Station de Radioastronomie de Nançay Observatoire de Paris CNRS/INSU Université d'Orléans Nançay18330 France 9 Laboratoire de Physique et Chimie de l'Environnement CNRS 3A Avenue de la Recherche Scientifique Orléans Cedex 245071 France Cornell Center for Astrophysics and Planetary Science and Department of Astronomy Cornell Unive

PSR J0740+6620 has a gravitational mass of 2:08 ± 0:07 Mo, which is the highest reliably determined mass of any neutron star. As a result, a measurement of its radius will provide unique insight into the properties of neutron star core matter at high densities. Here we report a radius measurement based on fits of rotating hot spot patterns to Neutron Star Interior Composition Explorer (NICER) and X-ray Multi-Mirror (XMM-Newton) X-ray observations. We find that the equatorial circumferential radius of PSR J0740+6620 is 13:7+2:6-1:5 km (68%). We apply our measurement, combined with the previous NICER mass and radius measurement of PSR J0030+0451, the masses of two other ∼ 2 Mo pulsars, and the tidal deformability constraints from two gravitational wave events, to three different frameworks for equation of state modeling, and find consistent results at ∼ 1:5-3 times nuclear saturation density. For a given framework, when all measurements are included the radius of a 1:4 Mo neutron star is known to ±4% (68% credibility) and the radius of a 2:08 Mo neutron star is known to ±5%. The full radius range that spans the ±1σ credible intervals of all the radius estimates in the three frameworks is 12:45±0:65 km for a 1:4 Mo neutron star and 12:35±0:75 km for a 2:08 Mo neutron star. Copyright © 2021, The Authors. All rights reserved.

关键词： Equations of state

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SN 2020bvc: A broad-lined type Ic supernova with a double-peaked optical light curve and a luminous X-ray and radio counterpart

arXiv

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arXiv 2020年

作者： Ho, Anna Y.Q. Kulkarni, S.R. Perley, Daniel A. Bradley Cenko, S. Corsi, Alessandra Schulze, Steve Lunnan, Ragnhild Sollerman, Jesper Gal-Yam, Avishay Anand, Shreya Barbarino, Cristina Bellm, Eric C. Bruch, Rachel J. Burns, Eric De, Kishalay Dekany, Richard Delacroix, Alexandre Duev, Dmitry A. Fremling, Christoffer Goldstein, Daniel A. Zach Golkhou, V. Graham, Matthew J. Hale, David Kasliwal, Mansi M. Kupfer, Thomas Laher, Russ R. Martikainen, Julia Masci, Frank J. Neill, James D. Rusholme, Ben Shupe, David L. Soumagnac, Maayane T. Strotjohann, Nora L. Taggart, Kirsty Tartaglia, Leonardo Yan, Lin Zolkower, Jeffry Cahill Center for Astrophysics California Institute of Technology MC 249-17 1200 E California Boulevard PasadenaCA91125 United States Astrophysics Research Institute Liverpool John Moores University IC2 Liverpool Science Park 146 Brownlow Hill LiverpoolL3 5RF United Kingdom Astrophysics Science Division NASA Goddard Space Flight Center Mail Code 661 GreenbeltMD20771 United States Joint Space-Science Institute University of Maryland College ParkMD20742 United States Department of Physics and Astronomy Texas Tech University Box 1051 LubbockTX79409-1051 United States Department of Particle Physics and Astrophysics Weizmann Institute of Science 234 Herzl St Rehovot76100 Israel The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-106 91 Sweden Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States DIRAC Institute Department of Astronomy University of Washington 3910 15th Avenue NE SeattleWA98195 United States Department of Particle Physics and Astrophysics Weizmann Institute of Science Rehovot76100 Israel NASA Postdoctoral Program Fellow Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics & Astronomy Louisiana State University Baton RougeLA70803 United States Caltech Optical Observatories California Institute of Technology PasadenaCA91125 United States eScience Institute University of Washington SeattleWA98195 United States Kavli Institute for Theoretical Physics University of California Santa BarbaraCA93106 United States IPAC California Institute of Technology 1200 E. California Blvd PasadenaCA91125 United States Department of Physics University of Helsinki P.O. box 64 FI-00014 Finland Nordic Optical Telescope Roque de Los Muchachos Observatory Rambla Jos Ana Fernndez Prez 7 Brea Baja La Palma Canarias38711 Spain Lawrence Berkeley National Laboratory 1 Cyclotron Road BerkeleyCA94720 United Sta

We present optical, radio, and X-ray observations of SN 2020bvc (=ASASSN20bs;ZTF20aalxlis), a nearby (z = 0.0252;d = 114 Mpc) broad-lined (BL) Type Ic supernova (SN). Our observations show that SN 2020bvc shares several properties in common with the Ic-BL SN 2006aj, which was associated with the low-luminosity gamma-ray burst (LLGRB) 060218. First, the 10 GHz radio light curve is on the faint end of LLGRB-SNe (Lradio ≈ 1037 erg s−1): we model our VLA observations (spanning 13-43 d) as synchrotron emission from a mildly relativistic (v & 0.3c) forward shock. Second, with Swift and Chandra we detect X-ray emission (LX ≈ 1041 erg s−1) that is not naturally explained as inverse Compton emission or as part of the same synchrotron spectrum as the radio emission. Third, high-cadence (6×/night) data from the Zwicky Transient Facility (ZTF) shows a double-peaked optical light curve, the first peak from shock-cooling emission from extended low-mass material (mass M −2 M at radius R > 1012 cm) and the second peak from the radioactive decay of 56Ni. SN 2020bvc is the first confirmed double-peaked Ic-BL SN discovered without a GRB trigger, and shows X-ray and radio emission similar to LLGRB-SNe: this is consistent with models in which the same mechanism produces both the LLGRB and the shock-cooling emission. For four of the five other nearby (z. 0.05) Ic-BL SNe with ZTF high-cadence data, we rule out a first peak like that seen in SN 2006aj and SN 2020bvc, i.e. that lasts ≈ 1 d and reaches a peak luminosity M ≈ −18. X-ray and radio follow-up observations of future such events will establish whether double-peaked optical light curves are indeed predictive of LLGRB-like X-ray and radio emission. Copyright © 2020, The Authors. All rights reserved.

关键词： Supernovae

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Ultra-Stable environment control for the neid spectrometer: Design and performance demonstration

arXiv

引用

arXiv 2019年

作者： Robertson, Paul Anderson, Tyler Stefansson, Gudmundur Hearty, Frederick R. Monsonb, Andrew Mahadevan, Suvrath Blakesle, Scott Bendere, Chad Ninan, Joe P. Conran, David Levi, Eric Lubar, Emily Cole, Amanda Dykhouse, Adam Kanodia, Shubham Nitroy, Colin Smolsky, Joseph Tuggle, Demetrius Blank, Basil Nelson, Matthew Blake, Cullen Halverson, Samuel Henderson, Chuck Kaplan, Kyle F. Li, Dan Logsdon, Sarah E. McElwain, Michael W. Rajagopal, Jayadev Ramsey, Lawrence W. Roy, Arpita Schwab, Christian Ryan, Terrien R. Wright, Jason T. University of California Department of Physics and Astronomy 4129 Frederick Reines Hall IrvineCA92697 United States Pennsylvania State University Department of Astronomy And Astrophysics University ParkPA United States NASA Earth and Space Science Pennsylvania State University Center for Exoplanets AND Habitable Worlds University ParkPA United States University of Arizona Department of Astronomy Steward Observatory TucsonAZ United States Pennsylvania State University College of Engineering University ParkPA United States Pennsylvania State University Department of Physics University ParkPA United States Massachusetts Institute of Technology Laboratory for Nuclear Science CambridgeMA United States Ohio State University Department of Astronomy ColumbusOH United States PulseRay Inc. Beaver DamsNY United States University of Virginia Department of Astronomy CharlottesvilleVA United States University of Pennsylvania Department of Physics and Astronomy PhiladelphiaPA United States NASA Sagan Massachusetts Institute of Technology Department of Physics CambridgeMA United States Cornell University IthacaNY United States National Optical Astronomy Observatory NASA Postdoctoral Program NASA Goddard Space Flight Center Exoplanets and Stellar Astrophysics Laboratory NASA Goddard Space Flight Center GreenbeltMD United States California Institute of Technology Department of Astronomy PasadenaCA United States Macquarie University Department of Physics And Astronomy Sydney Australia Carleton College Department of Physics AND Astronomy NorthfieldMN United States

Two key areas of emphasis in contemporary experimental exoplanet science are the detailed characterization of transiting terrestrial planets, and the search for Earth analog planets to be targeted by future imaging missions. Both of these pursuits are dependent on an order-of-magnitude improvement in the measurement of stellar radial velocities (RV), setting a requirement on single-measurement instrumental uncertainty of order 10 cm/s. Achieving such extraordinary precision on a high-resolution spectrometer requires thermo-mechanically stabilizing the instrument to unprecedented levels. Here, we describe the Environment Control System (ECS) of the NEID Spectrometer, which will be commissioned on the 3.5m WIYN Telescope at Kitt Peak National Observatory in 2019, and has a performance specification of on-sky RV precision Copyright © 2019, The Authors. All rights reserved.

关键词： Temperature control

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Earthshine as an Illumination Source at the Moon

arXiv

引用

arXiv 2019年

作者： Glenar, David A. Stubbs, Timothy J. Schwieterman, Edward W. Robinson, Tyler D. Livengood, Timothy A. Center for Space Science and Technology University of Maryland Baltimore County BaltimoreMD21218 Solar System Exploration Research Virtual Institute/SSERVI NASA Ames Research Center Moffett FieldCA94035 NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Earth Sciences University of California Riverside RiversideCA92521 United States NASA Postdoctoral Program Universities Space Research Association ColumbiaMD United States Blue Marble Space Institute of Science SeattleWA United States NASA Astrobiology Institute Virtual Planetary Laboratory SeattleWA98195 Department of Physics and Astronomy Northern Arizona University FlagstaffAZ86011 United States

Earthshine is the dominant source of natural illumination on the surface of the Moon during lunar night, and at some locations within permanently shadowed regions (PSRs) near the poles that never receive direct sunlight. As such, earthshine has the potential to enable the scientific investigation and exploration of conditions in areas of the Moon that are either temporarily or permanently hidden from the Sun. Under certain circumstances, the heat flux from earthshine could also influence the transport and cold-trapping of volatiles present in the very coldest areas within PSRs. In this study, Earth’s spectral irradiance, as it would appear at the Moon in the solar reflectance band (0.3–3.0 µm) and at thermal emission wavelengths (3–50 µm), is examined with a suite of model image cubes and whole-disk spectra created using the Virtual Planetary Laboratory (VPL) three-dimensional (latitude, longitude and altitude) modeling capability. At the Moon, the broadband, hemispherical irradiance from Earth at full-phase is approximately 0.15 W m−2 with comparable contributions from solar reflectance and thermal emission;for context, this about 0.01% that of solar irradiance and has an equivalent temperature of around 40 K. Over the simulated timeframe, spanning two lunations, Earth’s thermal irradiance shows very little net change (less than a few mWm−2 resulting from cloud variability and the south-to-north motion of the sub-observer latitude on Earth). In the solar band, Earth’s diurnally averaged light curve at phase angles g ≤ 60° is well-fit using a Henyey-Greenstein integral phase function. At wavelengths longward of about 0.7 µm, near the well-known vegetation "red edge", Earth’s reflected solar radiance shows significant diurnal modulation as a result of the broad maximum in projected landmass at terrestrial longitudes between 60°W and 0°, as well as from the distribution of clouds. A simple formulation with adjustable coefficients is presented, condensed from the VPL m

关键词： Ultraviolet spectroscopy

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Double dark matter vision: Twice the number of compact-source lenses with narrow-line lensing and the WFC3 Grism

arXiv

引用

arXiv 2019年

作者： Nierenberg, A.M. Gilman, D. Treu, T. Brammer, G. Birrer, S. Moustakas, L. Agnello, A. Anguita, T. Fassnacht, C.D. Motta, V. Peter, A.H.G. Sluse, D. Jet Propulsion Laboratory California Institute of Technology NASA Postdoctoral Program Fellow UCLA Physics and Astronomy 475 Portola Plaza Los AngelesCA90095-1547 United States Packard Fellow Cosmic Dawn Center Rockefeller Komplesket Niels Bohr Institute Juliane Ma2100 DARK Niels-Bohr Institute Lyngbyvej 2 2100 Denmark Departamento de Ciencias Fisicas Universidad Andres Bello Fernandez Concha 700 Las Condes Santiago Chile Millennium Institute of Astrophysics UC Davis Department of Physics 1 Shields Ave. DavisCA95616 United States Instituto de Física y Astronomiá Universidad de Valparaíso Avda. Gran Bretanã 1111 Valparaíso Chile Center for Cosmology and AstroParticle Physics Ohio State University 191 West Woodruff Avenue ColumbusOH43204 United States Department of Physics Ohio State University 191 West Woodruff Avenue ColumbusOH43204 United States Department of Astronomy Ohio State University McPherson Laboratory 140 West 18th Avenue ColumbusOH United States STAR Institute Allé du six Août 19c LiègeB-4000 Belgium

The magnifications of compact-source lenses are extremely sensitive to the presence of low mass dark matter halos along the entire sight line from the source to the observer. Traditionally, the study of dark matter structure in compact-source strong gravitational lenses has been limited to radio-loud systems, as the radio emission is extended and thus unaffected by microlensing which can mimic the signal of dark matter structure. An alternate approach is to measure quasar nuclear-narrow line emission, which is free from microlensing and present in virtually all quasar lenses. In this paper, we double the number of systems which can be used for gravitational lensing analyses by presenting measurements of narrow-line emission from a sample of 8 quadruply imaged quasar lens systems, WGD J0405-3308, HS 0810+2554, RX J0911+0551, SDSS J1330+1810, PS J1606-2333, WFI 2026-4536, WFI 2033-4723 and WGD J2038-4008. We describe our updated grism spectral modelling pipeline, which we use to measure narrow-line fluxes with uncertainties of 2-10%, presented here. We fit the lensed image positions with smooth mass models and demonstrate that these models fail to produce the observed distribution of image fluxes, and have typical deviations larger than those expected from macromodel uncertainties. This discrepancy indicates the presence of perturbations caused by small-scale dark matter structure. The interpretation of this result in terms of dark matter models will be presented in a companion paper. Copyright © 2019, The Authors. All rights reserved.

关键词： Galaxies

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A limited habitable zone for complex life

arXiv

引用

arXiv 2019年

作者： Schwieterman, Edward W. Reinhard, Christopher T. Lyons, Timoth W. Olson, Stephanie L. Harman, Chester E. Department of Earth and Planetary Sciences University of California RiversideCA United States NASA Postdoctoral Program Universities Space Research Association ColumbiaMD United States NASA Astrobiology Institute Alternative Earths Team RiversideCA United States Virtual Planetary Laboratory SeattleWA United States Bl M bl S I tit t f S i S ttl W hi t United States School of Earth and Atmospheric Sciences Georgia Institute of Technology AtlantaGA United States De artment of Geo h sical Sciences Universit of Chica o Chica o IL United States NASA Goddard Institute for S ace Studies New YorkNY United States Department of Applied Mathematics and Applied Physics Columbia University New YorkNY United States

The habitable zone (HZ) is commonly defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist on a planet’s surface. Substantially more CO2 than present in Earth’s modern atmosphere is required to maintain clement temperatures for most of the HZ, with several bars required at the outer edge. However, most complex aerobic life on Earth is limited by CO2 concentrations of just fractions of a bar. At the same time, most exoplanets in the traditional HZ reside in proximity to M dwarfs, which are more numerous than Sun-like G dwarfs but are predicted to promote greater abundances of gases that can be toxic in the atmospheres of orbiting planets, such as carbon monoxide (CO). Here we show that the HZ for complex aerobic life is likely limited relative to that for microbial life. We use a 1D radiative-convective climate and photochemical models to circumscribe a Habitable Zone for Complex Life (HZCL) based on known toxicity limits for a range of organisms as a proof of concept. We find that for CO2 tolerances of 0.01, 0.1, and 1 bar, the HZCL is only 21%, 32%, and 50% as wide as the conventional HZ for a Sun-like star, and that CO concentrations may limit some complex life throughout the entire HZ of the coolest M dwarfs. These results cast new light on the likely distribution of complex life in the universe and have important ramifications for the search for exoplanet biosignatures and technosignatures. Copyright © 2019, The Authors. All rights reserved.

关键词： Carbon monoxide

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Rethinking CO antibiosignatures in the search for life beyond the solar system

arXiv

引用

arXiv 2019年

作者： Schwieterman, Edward W. Reinhard, Christopher T. Olson, Stephanie L. Ozaki, Kazumi Harman, Chester E. Hong, Peng K. Lyons, Timothy W. Department of Earth Sciences University of California RiversideCA United States NASA Postdoctoral Program Universities Space Research Association ColumbiaMD United States NASA Astrobiology Institute Alternative Earths & Virtual Planetary Laboratory Teams United States Blue Marble Space Institute of Science SeattleWA United States School of Earth and Atmospheric Sciences Georgia Institute of Technology AtlantaGA United States Department of Geophysical Sciences University of Chicago ChicagoIL United States Department of Environmental Science Toho University Tokyo Japan NASA Goddard Institute for Space Studies New YorkNY United States Department of Applied Mathematics and Applied Physics Columbia University New YorkNY United States Planetary Exploration Research Center Chiba Institute of Technology 2-17-1 Tsudanuma Narashino Chiba275-0016 Japan

Some atmospheric gases have been proposed as counter indicators to the presence of life on an exoplanet if remotely detectable at sufficient abundance (i.e., antibiosignatures), informing the search for biosignatures and potentially fingerprinting uninhabited habitats. However, the quantitative extent to which putative antibiosignatures could exist in the atmospheres of inhabited planets is not well understood. The most commonly referenced potential antibiosignature is CO, because it represents a source of free energy and reduced carbon that is readily exploited by life on Earth and is thus often assumed to accumulate only in the absence of life. Yet, biospheres actively produce CO through biomass burning, photooxidation processes, and release of gases that are photochemically converted into CO in the atmosphere. We demonstrate with a 1D ecosphere-atmosphere model that reducing biospheres can maintain CO levels of ~100 ppmv even at low H2fluxes due to the impact of hybrid photosynthetic ecosystems. Additionally, we show that photochemistry around M dwarf stars is particularly favorable for the buildup of CO, with plausible concentrations for inhabited, oxygen-rich planets extending from hundreds of ppm to several percent. Since CH4buildup is also favored on these worlds, and because O2and O3are likely not detectable with the James Webb Space Telescope, the presence of high CO (>100 ppmv) may discriminate between oxygen-rich and reducing biospheres with near-future transmission observations. These results suggest that spectroscopic detection of CO can be compatible with the presence of life and that a comprehensive contextual assessment is required to validate the significance of potential antibiosignatures. Copyright © 2019, The Authors. All rights reserved.

关键词： Free energy

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Detection of CMB-Cluster Lensing using Polarization Data from SPTpol

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Physical Review Letters 2019年第18期123卷 181301-181301页

作者： S. Raghunathan S. Patil E. Baxter B. A. Benson L. E. Bleem T. M. Crawford G. P. Holder T. McClintock C. L. Reichardt T. N. Varga N. Whitehorn P. A. R. Ade S. Allam A. J. Anderson J. E. Austermann S. Avila J. S. Avva D. Bacon J. A. Beall A. N. Bender F. Bianchini S. Bocquet D. Brooks D. L. Burke J. E. Carlstrom J. Carretero F. J. Castander C. L. Chang H. C. Chiang R. Citron M. Costanzi A. T. Crites L. N. da Costa S. Desai H. T. Diehl J. P. Dietrich M. A. Dobbs P. Doel S. Everett A. E. Evrard C. Feng B. Flaugher P. Fosalba J. Frieman J. Gallicchio J. García-Bellido E. Gaztanaga E. M. George T. Giannantonio A. Gilbert R. A. Gruendl J. Gschwend N. Gupta G. Gutierrez T. de Haan N. W. Halverson N. Harrington J. W. Henning G. C. Hilton D. L. Hollowood W. L. Holzapfel K. Honscheid J. D. Hrubes N. Huang J. Hubmayr K. D. Irwin T. Jeltema M. Carrasco Kind L. Knox N. Kuropatkin O. Lahav A. T. Lee D. Li M. Lima A. Lowitz M. A. G. Maia J. L. Marshall J. J. McMahon P. Melchior F. Menanteau S. S. Meyer R. Miquel L. M. Mocanu J. J. Mohr J. Montgomery C. Corbett Moran A. Nadolski T. Natoli J. P. Nibarger G. Noble V. Novosad R. L. C. Ogando S. Padin A. A. Plazas C. Pryke D. Rapetti A. K. Romer A. Roodman A. Carnero Rosell E. Rozo J. E. Ruhl E. S. Rykoff B. R. Saliwanchik E. Sanchez J. T. Sayre V. Scarpine K. K. Schaffer M. Schubnell S. Serrano I. Sevilla-Noarbe C. Sievers G. Smecher M. Smith M. Soares-Santos A. A. Stark K. T. Story E. Suchyta M. E. C. Swanson G. Tarle C. Tucker K. Vanderlinde T. Veach J. De Vicente J. D. Vieira V. Vikram G. Wang W. L. K. Wu V. Yefremenko Y. Zhang Department of Physics and Astronomy University of California Los Angeles California 90095 USA School of Physics University of Melbourne Parkville VIC 3010 Australia Department of Physics and Astronomy University of Pennsylvania Philadelphia Pennsylvania 19104 USA Fermi National Accelerator Laboratory MS209 P.O. Box 500 Batavia Illinois 60510 USA Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue Argonne Illinois 60439 USA Astronomy Department University of Illinois at Urbana-Champaign 1002 W. Green Street Urbana Illinois 61801 USA Department of Physics University of Illinois Urbana-Champaign 1110 W. Green Street Urbana Illinois 61801 USA Canadian Institute for Advanced Research CIFAR Program in Gravity and the Extreme Universe Toronto Ontario M5G 1Z8 Canada Department of Physics University of Arizona Tucson Arizona 85721 USA Max Planck Institute for Extraterrestrial Physics Giessenbachstrasse Garching 85748 Germany Universitäts-Sternwarte Fakultät für Physik LudwigMaximilians Universität München Scheinerstr. 1 München 81679 Germany Cardiff University Cardiff CF10 3XQ United Kingdom Fermi National Accelerator Laboratory P. O. Box 500 Batavia Illinois 60510 USA NIST Quantum Devices Group 325 Broadway Mailcode 817.03 Boulder Colorado 80305 USA Instituto de Fisica Teorica UAM/CSIC Universidad Autonoma de Madrid 28049 Madrid Spain Department of Physics University of California Berkeley California 94720 USA Institute of Cosmology & Gravitation University of Portsmouth Dennis Sciama Building Burnaby Road Portsmouth PO1 3FX United Kingdom Faculty of Physics Ludwig-Maximilians-Universität Scheinerstr. 1 Munich 81679 Germany Department of Physics & Astronomy University College London Gower

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg2 survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×1014M⊙ which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

关键词： Cosmic microwave background Gravitational lenses Galaxy clusters

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QUANTIFYING FEEDBACK FROM NARROW LINE REGION OUTFLOWS IN NEARBY ACTIVE GALAXIES. I. SPATIALLY RESOLVED MASS OUTFLOW RATES FOR THE SEYFERT 2 GALAXY MARKARIAN 573†★

arXiv

引用

arXiv 2018年

作者： Revalski, M. Crenshaw, D.M. Kraemer, S.B. Fischer, T.C. Schmitt, H.R. Machuca, C. Department of Physics and Astronomy Georgia State University 25 Park Place Suite 605 AtlantaGA30303 United States Institute for Astrophysics and Computational Sciences Department of Physics Catholic University of America WashingtonDC20064 United States Astrophysics Science Division Goddard Space Flight Center Code 665 GreenbeltMD20771 United States Naval Research Laboratory WashingtonDC20375 United States Department of Astronomy University of Wisconsin–Madison 475 North Charter Street MadisonWI53707 United States National Science Foundation Graduate Research Fellow DGE1550139 James Webb Space Telescope NASA Postdoctoral Program Fellow

We present the first spatially resolved mass outflow rate measurements (M·out) of the optical emission line gas in the narrow line region (NLR) of a Seyfert 2 galaxy, Markarian 573. Using long slit spectra and [O III] imaging from the Hubble Space Telescope and Apache Point Observatory in conjunction with emission line diagnostics and Cloudy photoionization models, we find a peak outflow rate of M·out ≈ 3.4 ± 0.5 M☉ yr−1 at a distance of 210 pc from the central supermassive black hole (SMBH). The outflow extends to distances of 600 pc from the nucleus with a total mass and kinetic energy of M ≈ 2.2 × 106M☉ and E ≈ 5.1 × 1054 erg, revealing the outflows to be more energetic than those in the lower luminosity Seyfert 1 galaxy NGC 4151 (Crenshaw et al. 2015). The peak outflow rate is an order of magnitude larger than the mass accretion and nuclear outflow rates, indicating local in-situ acceleration of the circumnuclear NLR gas. We compare these results to global techniques that quantify an average outflow rate across the NLR, and find the latter are subject to larger uncertainties. These results indicate that spatially resolved observations are critical for probing AGN feedback on scales where circumnuclear star formation occurs. Subject headings: galaxies: active – galaxies: individual (Mrk 573) – galaxies: kinematics and dynamics – galaxies: Seyfert – ISM: jets and outflows Copyright © 2018, The Authors. All rights reserved.

关键词： Galaxies

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Sensitivity of gravitational wave searches to the full signal of intermediate mass black hole binaries during the LIGO O1 science run

arXiv

引用

arXiv 2017年

作者： Bustillo, Juan Calderón Salemi, Francesco Canton, Tito Dal Jani, Karan P. Center for Relativistic Astrophysics School of Physics Georgia Institute of Technology AtlantaGA30332 United States Callinstrasse 38 Hannover Germany NASA Postdoctoral Program Fellow Goddard Space Flight Center GreenbeltMD20771 United States

The sensitivity of gravitational wave searches for binary black holes is estimated via the injection and posterior recovery of simulated gravitational wave signals in the detector data streams. When a search reports no detections, the estimated sensitivity is then used to place upper limits on the coalescence rate of the target source. In order to obtain correct sensitivity and rate estimates, the injected waveforms must be faithful representations of the real signals. Up to date, however, injected waveforms have neglected radiation modes of order higher than the quadrupole, potentially biasing sensitivity and coalescence rate estimates. In particular, higher-order modes are known to have a large impact in the gravitational waves emitted by intermediate mass black holes binaries. In this work we evaluate the impact of this approximation in the context of two search algorithms run by the LIGO Scientific Collaboration in their search for intermediate mass black hole binaries in the O1 LIGO Science Run data: a matched-filter based pipeline and a coherent un-modeled one. To this end we estimate the sensitivity of both searches to simulated signals including and omitting higher-order modes. We find that omission of higher-order modes leads to biases in the sensitivity estimates which depend on the masses of the binary, the search algorithm and the required level of significance for detection. In addition, we compare the sensitivity of the two search algorithms across the studied parameter space. We conclude that the most recent LIGO-Virgo upper limits on the rate of coalescence of intermediate mass black hole binaries are conservative for the case of highly asymmetric binaries. However, the tightest upper limits, placed for nearly-equal-mass sources, remain unchanged due to the small contribution of higher modes to the corresponding sources. Copyright © 2017, The Authors. All rights reserved.

关键词： Learning algorithms

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