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Revised and updated catalogue of the First Byurakan Survey of late-type stars
Gigoyan, K. S.; Mickaelian, A. M.
There have been 15 lists of late-type stars published between 1990 and 2010. These late-type stars have been found in the low-dispersion spectroscopic plates of the First Byurakan Survey (FBS). The systematic search and selection was carried out on a surface ∼16 000 deg2 on almost the whole area of the FBS. As a result, a comprehensive …
Accurate classification of 29 objects detected in the 39 month Palermo Swift/BAT hard X-ray catalogue
Palazzi, E.; Minniti, D.; Masetti, N. +15 more
Through an optical campaign performed at four telescopes located in the northern and the southern hemispheres, plus archival data from two on-line sky surveys, we obtained optical spectroscopy for 29 counterparts of unclassified or poorly studied hard X-ray emitting objects detected with Swift /Burst Alert Telescope (BAT) and listed in the 39 mont…
Joint spectral-timing modelling of the hard lags in GX 339-4: constraints on reflection models
Wilms, J.; Uttley, P.; Cassatella, P. +1 more
The X-ray variations of hard state black hole X-ray binaries above 2 keV show 'hard lags', in that the variations at harder energies follow variations at softer energies, with a time lag τ depending on frequency ν approximately as τ∝ν-0.7. Several models have so far been proposed to explain this time delay, including fluctuations propag…
Formation, shape, and evolution of magnetic structures in CIRs at 1 AU
McComas, D. J.; Desai, M. I.; Broiles, T. W.
We have surveyed the properties of 153 co-rotating interaction regions (CIRs) observed at 1 AU from January, 1995 through December, 2008. We identified that 74 of the 153 CIRs contain planar magnetic structures (PMSs). For planar and non-planar CIRs, we compared distributions of the bulk plasma and magnetic field parameters. Our identification of …
Triaxiality, principal axis orientation and non-thermal pressure in Abell 383
Limousin, Marceau; Morandi, Andrea
While clusters of galaxies are regarded as one of the most important cosmological probes, the conventional spherical modelling of the intracluster medium and the dark matter (DM), and the assumption of strict hydrostatic equilibrium (i.e. the equilibrium gas pressure is provided entirely by thermal pressure) are very approximate at best. Extending…
VLBI Astrometry of the Semiregular Variable RX Bootis
Tafoya, Daniel; Kurayama, Tomoharu; Honma, Mareki +10 more
We present distance measurements of the semiregular variable RX Bootis (RX Boo) with its annual parallax. Using the unique dual-beam system of the VLBI Exploration of Radio Astrometry (VERA) telescope, we conducted astrometric observations of a water maser spot accompanying RX Boo, referred to the quasar J1419+2706 separated by 1.°69 from RX Boo. …
Discovery of the Most Isolated Globular Cluster in the Local Universe
Lee, Myung Gyoon; Jang, In Sung; Lim, Sungsoon +1 more
We report the discovery of two new globular clusters in the remote halos of M81 and M82 in the M81 Group based on Hubble Space Telescope archive images. They are brighter than typical globular clusters (MV = -9.34 mag for GC-1 and MV = -10.51 mag for GC-2), and much larger than known globular clusters with similar luminosity …
Formulation of a wind specification for Titan late polar summer exploration
Achterberg, Richard K.; Lorenz, Ralph D.; Tokano, Tetsuya +4 more
Titan's polar regions, and its hydrocarbon lakes in particular, are of interest for future exploration. The polar conditions have considerable seasonal variation and are distinct from the equatorial environment experienced by Huygens. Thus specific environmental models are required for these regions. This paper, informed by Cassini and groundbased…
Recurrent Radio Outbursts at the Center of the NGC 1407 Galaxy Group
Raychaudhury, Somak; Clarke, Tracy E.; Giacintucci, Simona +6 more
We present deep Giant Metrewave Radio Telescope (GMRT) radio observations at 240, 330, and 610 MHz of the complex radio source at the center of the NGC 1407 galaxy group. Previous GMRT observations at 240 MHz revealed faint, diffuse emission enclosing the central twin-jet radio galaxy. This has been interpreted as an indication of two possible rad…
The Free Energy of NOAA Solar Active Region AR 11029
Leka, K. D.; Wheatland, M. S.; Gilchrist, S. A.
The NOAA active region (AR) 11029 was a small but highly active sunspot region which produced 73 GOES soft X-ray flares during its transit of the disk in late October 2009. The flares appear to show a departure from the well-known power law frequency-size distribution. Specifically, too few GOES C-class and no M-class flares were observed by compa…