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A Massive Neutron Star in the Globular Cluster M5
Freire, Paulo C. C.; Hessels, Jason W. T.; van den Berg, Maureen +1 more
We report the results of 19 years of Arecibo timing for two pulsars in the globular cluster NGC 5904 (M5), PSR B1516+02A (M5A) and PSR B1516+02B (M5B). This has resulted in the measurement of the proper motions of these pulsars and, by extension, that of the cluster itself. M5B is a 7.95 ms pulsar in a binary system with a >0.13 M⊙ c…
Precise Measurement of the Spin Parameter of the Stellar-Mass Black Hole M33 X-7
McClintock, Jeffrey E.; Liu, Jifeng; Davis, Shane W. +2 more
In prior work, Chandra and Gemini-North observations of the eclipsing X-ray binary M33 X-7 have yielded measurements of the mass of its black hole primary and the system's orbital inclination angle of unprecedented accuracy. Likewise, the distance to the binary is known to a few percent. In an analysis based on these precise results, 15 Chandra an…
Saturn kilometric radiation: Average and statistical properties
Gurnett, D. A.; Kurth, W. S.; Cecconi, B. +3 more
Since Cassini entered Saturn's magnetosphere in July 2004, the auroral Saturnian kilometric radiation (SKR), which dominates the kronian radio spectrum, is observed quasi-continuously. Consecutive orbits of the spacecraft covered distances to Saturn down to 1.3 Saturn radii, all local times and, since December 2006, latitudes as high as 60°. On th…
X-ray spectra from magnetar candidates - I. Monte Carlo simulations in the non-relativistic regime
Zane, S.; Nobili, L.; Turolla, R.
The anomalous X-ray pulsars (AXPs) and soft γ-repeaters (SGRs) are peculiar high-energy sources believed to host a magnetar, an ultramagnetized neutron star with surface magnetic field in the petagauss range. Their persistent, soft X-ray emission exhibits a two component spectrum, usually modelled by the superposition of a blackbody and a power-la…
Hubble Space Telescope Morphologies of Local Lyman Break Galaxy Analogs. I. Evidence for Starbursts Triggered by Merging
Charlot, Stéphane; Aloisi, Alessandra; Heckman, Timothy M. +10 more
Heckman and coworkers used the GALEX UV imaging survey to show that there exists a rare population of nearby compact UV-luminous galaxies (UVLGs) that closely resemble high-redshift Lyman break galaxies (LBGs). We present HST images in the UV, optical, and Hα and resimulate them at the depth and resolution of the GOODS/UDF fields to show that the …
Are Optically Selected Quasars Universally X-Ray Luminous? X-Ray-UV Relations in Sloan Digital Sky Survey Quasars
Brandt, W. N.; Schneider, Donald P.; Gibson, Robert R.
We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at 1.7 <= z<= 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray-weak, non-BAL QSOs and …
Variable winds on Venus mapped in three dimensions
Baines, K. H.; Hueso, R.; Sánchez-Lavega, A. +9 more
We present zonal and meridional wind measurements at three altitude levels within the cloud layers of Venus from cloud tracking using images taken with the VIRTIS instrument on board Venus Express. At low latitudes, zonal winds in the Southern hemisphere are nearly constant with latitude with westward velocities of 105 ms-1 at cloud-top…
A New Distance to the Antennae Galaxies (NGC 4038/39) Based on the Type Ia Supernova 2007sr
Schweizer, François; Madore, Barry F.; Freedman, Wendy L. +13 more
Traditionally, the distance to NGC 4038/39 has been derived from the systemic recession velocity, yielding about 20 Mpc for H 0 = 72 km s-1 Mpc-1. Recently, this widely adopted distance has been challenged based on photometry of the presumed tip of the red giant branch (TRGB), which seems to yield a shorter distanc…
X-ray spectral evolution of TeV BL Lacertae objects: eleven years of observations with BeppoSAX, XMM-Newton and Swift satellites
Tramacere, A.; Giommi, P.; Perri, M. +2 more
Context: Many of the extragalactic sources detected in γ rays at TeV energies are BL Lac objects. In particular, they belong to the subclass of “high frequency peaked BL Lacs” (HBLs), as their spectral energy distributions exhibit a first peak in the X-ray band. At a closer look, their X-ray spectra appear to be generally curved into a log-parabol…
Measuring suprathermal electron parameters in space plasmas: Implementation of the quasi-thermal noise spectroscopy with kappa distributions using in situ Ulysses/URAP radio measurements in the solar wind
Zouganelis, I.
We discuss the implementation of the quasi-thermal noise spectroscopy using kappa velocity distribution functions for the electrons. The quasi-thermal noise spectroscopy is a powerful tool for in situ space plasma diagnostics based on the analysis of the electrostatic field spectrum produced by the quasi-thermal fluctuations of electrons. The elec…