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HST-COS Observations of AGNs. III. Spectral Constraints in the Lyman Continuum from Composite COS/G140L Data
Stevans, Matthew L.; Shull, J. Michael; Danforth, Charles W. +1 more
The rest-frame ultraviolet (UV) spectra of active galactic nuclei (AGNs) are important diagnostics of both accretion disk physics and their contribution to the metagalactic ionizing UV background. Though the mean AGN spectrum is well characterized with composite spectra at wavelengths greater than 912 Å, the shorter-wavelength extreme-UV (EUV) rem…
Mirror mode structures ahead of dipolarization front near the neutral sheet observed by Cluster
Zhang, T. L.; Nakamura, R.; Baumjohann, W. +4 more
Magnetic compressional structures ahead of a dipolarization front (DF) on 30 August 2002 are investigated by using Cluster data. Our findings are as follows: (1) the structures, observed near the neutral sheet, are mainly compressional and dominant in BZ; (2) they are almost nonpropagating relative to the local ion bulk flow and their l…
Coronal Hole and Solar Global Magnetic Field Evolution in 1976 - 2012
Bilenko, Irina A.; Tavastsherna, Ksenia S.
We study the spatial-temporal evolution of a coronal hole and compare it with that of the solar global magnetic field in Cycles 21 - 23 (1976 - 2012). We also analyze the latitude-longitude distribution dynamics of coronal holes and the regularities in the global magnetic field associated with the solar polar field reversal. Polar and non-polar co…
Vetting Galactic Leavitt Law Calibrators Using Radial Velocities: On the Variability, Binarity, and Possible Parallax Error of 19 Long-period Cepheids
Holl, B.; Mowlavi, N.; Roelens, M. +9 more
We investigate the radial velocity (RV) variability and spectroscopic binarity of 19 Galactic long-period ({P}{puls} ≳ 10 days) classical Cepheid variable stars whose trigonometric parallaxes are being measured using the Hubble Space Telescope and Gaia. Our primary objective is to constrain possible parallax error due to undetected orbi…
Absolute Calibration of the Radio Astronomy Flux Density Scale at 22 to 43 GHz Using Planck
López-Caniego, M.; Partridge, B.; Rocha, G. +5 more
The Planck mission detected thousands of extragalactic radio sources at frequencies from 28 to 857 GHz. Planck's calibration is absolute (in the sense that it is based on the satellite’s annual motion around the Sun and the temperature of the cosmic microwave background), and its beams are well characterized at sub-percent levels. Thus, Planck's f…
The rotation-metallicity relation for the Galactic disk as measured in the Gaia DR1 TGAS and APOGEE data
Cropper, Mark; Kawata, Daisuke; Allende Prieto, Carlos
Aims: Previous studies have found that the Galactic rotation velocity-metallicity (V-[Fe/H]) relations for the thin and thick disk populations show negative and positive slopes, respectively. The first Gaia data release includes the Tycho-Gaia Astrometric Solution (TGAS) information, which we use to analyze the V-[Fe/H] relation for a strictl…
SHIELD: Neutral Gas Kinematics and Dynamics
McQuinn, Kristen B. W.; Cannon, John M.; Skillman, Evan D. +22 more
We present kinematic analyses of the 12 galaxies in the “Survey of H I in Extremely Low-mass Dwarfs” (SHIELD). We use multi-configuration interferometric observations of the H I 21 cm emission line from the Karl G. Jansky Very Large Array (VLA)22 to produce image cubes at a variety of spatial and spectral resolutions. Both two- and thre…
Two Distinct-absorption X-Ray Components from Type IIn Supernovae: Evidence for Asphericity in the Circumstellar Medium
Sugawara, Yasuharu; Katsuda, Satoru; Kawabata, Koji +7 more
We present multi-epoch X-ray spectral observations of three Type IIn supernovae (SNe), SN 2005kd, SN 2006jd, and SN 2010jl, acquired with Chandra, XMM-Newton, Suzaku, and Swift. Previous extensive X-ray studies of SN 2010jl have revealed that X-ray spectra are dominated by thermal emission, which likely arises from a hot plasma heated by a forward…
HERschel Observations of Edge-on Spirals (HEROES). III. Dust energy balance study of IC 2531
Mosenkov, Aleksandr V.; De Looze, Ilse; Baes, Maarten +11 more
We investigate the dust energy balance for the edge-on galaxy IC 2531, one of the seven galaxies in the HEROES sample. We perform a state-of-the-art radiative transfer modelling based, for the first time, on a set of optical and near-infrared galaxy images. We show that by taking into account near-infrared imaging in the modelling significantly im…
Galaxy populations in the 26 most massive galaxy clusters in the South Pole Telescope SPT-SZ survey
Rest, A.; Zenteno, A.; Desai, S. +13 more
We present a study of the optical properties of the 26 most massive galaxy clusters within the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) 2500 deg2 survey spanning the redshift range 0.10 < z < 1.13. We measure the radial profiles, the luminosity functions (LFs), and the halo occupation numbers (HONs) using optical data of t…