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Multicomponent decompositions for a sample of S0 galaxies
Salo, Heikki; Laurikainen, Eija; Buta, Ronald
We have estimated the bulge-to-total (B/T) light ratios in the Ks band for a sample of 24 S0, S0/a and Sa galaxies by applying a two-dimensional multicomponent decomposition method. For the disc an exponential function is used, the bulges are fitted by a Sérsic R1/n function and the bars and ovals are described either by a Sé…
How large are the bars in barred galaxies?
Erwin, Peter
I present a study of the sizes (semimajor axes) of bars in disc galaxies, combining a detailed R-band study of 65 S0-Sb galaxies with the B-band measurements of 70 Sb-Sd galaxies from Martin (1995). As has been noted before with smaller samples, bars in early-type (S0-Sb) galaxies are clearly larger than bars in late-type (Sc-Sd) galaxies; this is…
Local Helioseismology
Gizon, Laurent; Birch, Aaron C.
We review the current status of local helioseismology, covering both theoretical and observational results. After a brief introduction to solar oscillations and wave propagation through in-homogeneous media, we describe the main techniques of local helioseismology: Fourier-Hankel decomposition, ring-diagram analysis, time-distance helioseismology,…
Discovery of an X-Ray-luminous Galaxy Cluster at z=1.4
Böhringer, H.; Rosati, P.; Schwope, A. +4 more
We report the discovery of a massive, X-ray-luminous cluster of galaxies at z=1.393, the most distant X-ray-selected cluster found to date. XMMU J2235.3-2557 was serendipitously detected as an extended X-ray source in an archival XMM-Newton observation of NGC 7314. VLT FORS2 R- and z-band snapshot imaging reveals an overdensity of red galaxies in …
Super-Helium-rich Populations and the Origin of Extreme Horizontal-Branch Stars in Globular Clusters
Joo, Seok-Joo; Han, Sang-Il; Ree, Chang H. +7 more
Recent observations for the color-magnitude diagrams (CMDs) of the massive globular cluster ω Centauri have shown that it has a striking double main sequence (MS), with a minority population of bluer and fainter MS stars well separated from a majority population of MS stars. Here we confirm, with the most up-to-date Y2 isochrones, that …
Keck Spectroscopy of Distant GOODS Spheroidal Galaxies: Downsizing in a Hierarchical Universe
Treu, Tommaso; van Dokkum, Pieter G.; Ellis, Richard S. +1 more
We analyze the evolution of the fundamental plane for 141 field spheroidal galaxies in the redshift range 0.2<z<1.2, selected morphologically to a magnitude limit F850LP=22.43 in the northern field of the Great Observatories Origins Deep Survey. For massive galaxies, we find that the bulk of the star formation was completed prior to z=2. How…
Evidence for a co-moving sub-stellar companion of GQ Lup
Wuchterl, G.; Neuhäuser, R.; Guenther, E. W. +3 more
We present a companion of the ≤2 Myr young classical T Tauri star GQ Lup in the Lupus star forming region at 140 ± 50 pc from imaging, astrometry, and spectroscopy. With direct K-band imaging using VLT/NACO, we detected an object 6 mag fainter than GQ Lup located 0.7'' west of it. Compared to images obtained 2 to 5 years earlier with Subaru/CIAO a…
A Full View of EIT Waves
Chen, P. F.; Shibata, K.; Fang, C.
Early observations by the EUV Imaging Telescope (EIT) on the Solar and Heliospheric Observatory indicated that propagating diffuse wave fronts, now conventionally referred to as ``EIT waves,'' can often be seen on the solar disk with a propagation velocity several times smaller than that of Hα Moreton waves. They are almost always associated with …
Spatial Correlation of Solar-Wind Turbulence from Two-Point Measurements
Dasso, S.; Matthaeus, W. H.; Smith, C. W. +3 more
Interplanetary turbulence, the best studied case of low frequency plasma turbulence, is the only directly quantified instance of astrophysical turbulence. Here, magnetic field correlation analysis, using for the first time only proper two-point, single time measurements, provides a key step in unraveling the space-time structure of interplanetary …
Galactic Globular Cluster Relative Ages
Salaris, Maurizio; Recio-Blanco, Alejandra; Piotto, Giampaolo +5 more
We present accurate relative ages for a sample of 55 Galactic globular clusters. The ages have been obtained by measuring the difference between the horizontal branch and the turnoff in two internally photometrically homogeneous databases. The mutual consistency of the two data sets has been assessed by comparing the ages of 16 globular clusters i…