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IC 3599 Did It Again: A Second Outburst of the X-Ray Transient Seyfert 1.9 Galaxy
Komossa, S.; Saxton, Richard; Grupe, Dirk
We report on the Swift discovery of a second high-amplitude (factor 100) outburst of the Seyfert 1.9 galaxy IC 3599, and discuss implications for outburst scenarios. Swift detected this active galactic nucleus (AGN) again in 2010 February in X-rays at a level of (1.50 ± 0.11) × {{10}36} W (0.2-2.0 keV), which is nearly as luminous as th…
The Origin of the Spurious Iron Spread in the Globular Cluster NGC 3201
Massari, D.; Mucciarelli, A.; Ferraro, F. R. +2 more
NGC 3201 is a globular cluster suspected to have an intrinsic spread in the iron content. We re-analyzed a sample of 21 cluster stars observed with UVES-FLAMES at the Very Large Telescope and for which Simmerer et al. found a 0.4 dex wide [Fe/H] distribution with a metal-poor tail. We confirmed that when spectroscopic gravities are adopted, the de…
Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko
De Keyser, Johan; Gombosi, Tamas I.; Berthelier, Jean-Jacques +16 more
Aims: Far away from the Sun, at around 3 AU, the activity of comet 67P/Churyumov-Gerasimenko is low and changes with local time (solar insolation), with location (chemical heterogeneity of the surface), and with season. When the activity is very low because the total cross section of the comet against the Sun is small, the solar wind has acce…
CHO-bearing organic compounds at the surface of 67P/Churyumov-Gerasimenko revealed by Ptolemy
Andrews, D. J.; Sheridan, S.; Wright, I. P. +3 more
The surface and subsurface of comets preserve material from the formation of the solar system. The properties of cometary material thus provide insight into the physical and chemical conditions during their formation. We present mass spectra taken by the Ptolemy instrument 20 minutes after the initial touchdown of the Philae lander on the surface …
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - IV. Helium content and relative age of multiple stellar populations within NGC 6352
Salaris, M.; Anderson, J.; Milone, A. P. +14 more
In this paper, we combine Wide Field Camera3/UVIS F275W, F336W, and F438W data from the `UV Legacy Survey of Galactic Globular Clusters: Shedding Light on Their Populations and Formation' (GO 13297) Hubble Space Telescope Treasury programme with F606W, F625W, F658N, and F814W Advanced Camera for Surveys archive data for a multiwavelength study of …
CME Propagation: Where does Aerodynamic Drag 'Take Over'?
Vourlidas, Angelos; Subramanian, Prasad; Sachdeva, Nishtha +1 more
We investigate the Sun-Earth dynamics of a set of eight well observed solar coronal mass ejections (CMEs) using data from the Solar Terrestrial Relations Observatory spacecraft. We seek to quantify the extent to which momentum coupling between these CMEs and the ambient solar wind (i.e., the aerodynamic drag) influences their dynamics. To this end…
High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood
Schmitt, J. H. M. M.; Czesla, S.; Salz, M. +1 more
Giant gas planets in close proximity to their host stars experience strong irradiation. In extreme cases photoevaporation causes a transonic, planetary wind and the persistent mass loss can possibly affect the planetary evolution. We have identified nine hot Jupiter systems in the vicinity of the Sun, in which expanded planetary atmospheres should…
The Link between the Formation Rates of Clusters and Stars in Galaxies
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
The goal of this paper is to test whether the formation rate of star clusters is proportional to the star formation rate (SFR) in galaxies. As a first step, we present the mass functions of compact clusters younger than 10 Myr in seven star-forming galaxies of diverse masses, sizes, and morphologies: the Large and Small Magellanic Clouds, NGC 4214…
Galactic cold cores. VI. Dust opacity spectral index
Juvela, M.; Marshall, D. J.; Paladini, R. +13 more
Context. The Galactic Cold Cores project has carried out Herschel photometric observations of 116 fields where the Planck survey has found signs of cold dust emission. The fields contain sources in different environments and different phases of star formation. Previous studies have revealed variations in their dust submillimetre opacity.
Aims…
Probing the Dark Flow Signal in WMAP 9 -Year and Planck Cosmic Microwave Background Maps
Kocevski, D.; Atrio-Barandela, F.; Ebeling, H. +2 more
The “dark flow” dipole is a statistically significant dipole found at the position of galaxy clusters in filtered maps of Cosmic Microwave Background (CMB) temperature anisotropies. The dipole measured in WMAP 3-, 5-, and 7- year data releases was (1) mutually consistent, (2) roughly aligned with the all-sky CMB dipole, and (3) correlated with clu…