Search Publications
RBS 1032: A Tidal Disruption Event in Another Dwarf Galaxy?
Maksym, W. Peter; Lin, Dacheng; Irwin, Jimmy A.
RBS 1032 is a supersoft (Γ ~ 5), luminous (~1043 erg s-1) ROSAT PSPC source which has been associated with an inactive dwarf galaxy at z = 0.026, SDSS J114726.69+494257.8. We have analyzed an XMM-Newton observation that confirms that RBS 1032 is indeed associated with the dwarf galaxy. Moreover, RBS 1032 has undergone a facto…
Astrometric follow-up observations of directly imaged sub-stellar companions to young stars and brown dwarfs
Neuhäuser, R.; Schmidt, T. O. B.; Ginski, C. +4 more
The formation of massive planetary or brown dwarf companions at large projected separations from their host star is not yet well understood. In order to put constraints on formation scenarios, we search for signatures in the orbit dynamics of the systems. We are specifically interested in the eccentricities and inclinations since those parameters …
Solar cycle evolution of dipolar and pseudostreamer belts and their relation to the slow solar wind
Owens, M. J.; Crooker, N. U.; Lockwood, M.
Dipolar streamers are coronal structures formed by open solar flux converging from coronal holes of opposite polarity. Thus, the dipolar streamer belt traces the coronal foot point of the heliospheric current sheet, and it is strongly associated with the origin of slow solar wind. Pseudostreamers, on the other hand, separate converging regions of …
Mining the gap: evolution of the magnitude gap in X-ray galaxy groups from the 3-square-degree XMM coverage of CFHTLS
Finoguenov, A.; Popesso, P.; Salvato, M. +15 more
We present a catalog of 129 X-ray galaxy groups, covering a redshift range 0.04 <z< 1.23, selected in the ~3 deg2 part of the CFHTLS W1 field overlapping XMM observations performed under the XMM-LSS project. We carry out a statistical study of the redshift evolution out to redshift one of the magnitude gap between the first and th…
Variations in Abundance Enhancements in Impulsive Solar Energetic-Particle Events and Related CMEs and Flares
Reames, Donald V.; Kahler, Stephen W.; Cliver, Edward W.
We study event-to-event variations in the abundance enhancements of the elements He through Pb for Fe-rich impulsive solar energetic-particle (SEP) events, and their relationship with properties of associated coronal mass ejections (CMEs) and solar flares. Using a least-squares procedure we fit the power-law enhancement of element abundances as a …
Spatially resolved kinematics, galactic wind, and quenching of star formation in the luminous infrared galaxy IRAS F11506-3851
Maiolino, R.; Colina, L.; Arribas, S. +4 more
We present a multi-wavelength integral field spectroscopic (IFS) study of the low-z luminous infrared galaxy IRAS F11506-3851 (ESO 320-G030) on the basis of the moderate spectral resolution observations (R ~ 3400-4000) taken with the VIMOS and SINFONI instruments at the ESO VLT. The morphology and the 2D kinematics of the gaseous (neutral and ioni…
Caught in the act: measuring the changes in the corona that cause the extreme variability of 1H 0707-495
Fabian, A. C.; Gallo, L. C.; Kara, E. +1 more
The X-ray spectra of the narrow-line Seyfert 1 galaxy, 1H 0707-495, obtained with XMM-Newton, from time periods of varying X-ray luminosity are analysed in the context of understanding the changes to the X-ray emitting corona that lead to the extreme variability seen in the X-ray emission from active galactic nuclei (AGN). The emissivity profile o…
The multiwavelength polarization of Cygnus X-1
Shahbaz, Tariq; Russell, David M.
Polarization measurements of the microquasar Cygnus X-1 exist at γ-ray, X-ray, ultraviolet, optical and radio frequencies. The γ-ray emission has been shown to be highly linearly polarized. Here, we present new infrared polarimetric data of Cygnus X-1 taken with the 10.4 m Gran Telescopio Canarias and the 4.2 m William Herschel Telescope. We show …
CO/H2 Abundance Ratio ≈ 10-4 in a Protoplanetary Disk
Herczeg, Gregory J.; France, Kevin; Penton, Steven V. +1 more
The relative abundances of atomic and molecular species in planet-forming disks around young stars provide important constraints on photochemical disk models and provide a baseline for calculating disk masses from measurements of trace species. A knowledge of absolute abundances, those relative to molecular hydrogen (H2), are challengin…
The solar cycle dependence of the weak internetwork flux
McIntosh, Scott W.; Lites, Bruce W.; Centeno, Rebecca
We examine data from the Hinode Observing Program 79 (the "HOP 79" irradiance program) as observed using the Hinode Solar Optical Telescope Spectro-Polarimeter for systematic changes in the weakest observable magnetic flux during the period 2008-2013. At moderate latitudes we find no evidence for systematic changes as a function of time and solar …