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The Low End of the Supermassive Black Hole Mass Function: Constraining the Mass of a Nuclear Black Hole in NGC 205 via Stellar Kinematics
Joseph, Charles L.; Ferrarese, Laura; Merritt, David +1 more
Hubble Space Telescope (HST) images and spectra of the nucleated dwarf elliptical galaxy NGC 205 are combined with three-integral axisymmetric dynamical models to constrain the mass MBH of a putative nuclear black hole. This is only the second attempt, after M33, to use resolved stellar kinematics to search for a nuclear black hole with…
An Overdensity of Galaxies at z = 5.9 +/- 0.2 in the Hubble Ultra Deep Field Confirmed Using the ACS Grism
Daddi, E.; Panagia, N.; Ferguson, H. C. +17 more
We present grism spectra taken with the Advanced Camera for Surveys (ACS) to identify 29 red sources with (i775-z850)>=0.9 in the Hubble Ultra Deep Field (HUDF). Of these, 23 are found to be galaxies at redshifts between z=5.4 and 6.7, identified by the break at 1216 Å due to intergalactic medium (IGM) absorption; two are …
Dimensional analysis of observed structures using multipoint magnetic field measurements: Application to Cluster
Balogh, A.; Zhang, H.; Zong, Q. -G. +6 more
A new method is described to analyze the dimensional character of observed structures using multipoint magnetic field measurements of four or more spacecraft. The technique can provide three directions along which the magnetic field has the minimum, intermediate, and maximum derivatives if the magnetic gradient tensor G = $\nabla$$\vec{B at every …
INTEGRAL insight into the inner parts of the Galaxy. High mass X-ray binaries
Sunyaev, R.; Revnivtsev, M.; Lutovinov, A. +3 more
Since its launch INTEGRAL has devoted a significant fraction of its observing time to the Galactic plane region. We present the results of INTEGRAL observations of the inner spiral arms of the Galaxy (Norma, Scutum and Sagittarius) with attention to high mass X-ray binaries. The increased sensitivity of the survey and possibility to detect absorbe…
Hierarchical star formation in M 51: star/cluster complexes
Bastian, N.; Gieles, M.; Lamers, H. J. G. L. M. +1 more
We report on a study of young star cluster complexes in the spiral galaxy M 51. Recent studies have confirmed that star clusters do not form in isolation, but instead tend to form in larger groupings or complexes. We use HST broad and narrow band images (from both WFPC2 and ACS), along with BIMA-CO observations to study the properties and investig…
The lithium content of the Galactic Halo stars
Primas, F.; Charbonnel, C.
Thanks to the accurate determination of the baryon density of the universe by the recent cosmic microwave background experiments, updated predictions of the standard model of Big Bang nucleosynthesis now yield the initial abundance of the primordial light elements with unprecedented precision. In the case of ^7Li, the CMB+SBBN value is significant…
Polar shapelets
Refregier, Alexandre; Massey, Richard
The shapelets method for image analysis is based upon the decomposition of localized objects into a series of orthogonal components with convenient mathematical properties. We extend the `Cartesian shapelet' formalism from earlier work, and construct `polar shapelet' basis functions that separate an image into components with explicit rotational s…
High-Resolution Radio Observations of the Colliding-Wind Binary WR 140
Dougherty, S. M.; Claussen, M. J.; Zauderer, B. A. +2 more
Milliarcsecond resolution Very Long Baseline Array (VLBA) observations of the archetype W-R+O star colliding-wind binary (CWB) system WR 140 are presented for 23 epochs between orbital phases 0.74 and 0.97. At 8.4 GHz, the emission in the wind-collision region (WCR) is clearly resolved as a bow-shaped arc that rotates as the orbit progresses. We i…
Candidate Type II Quasars from the Sloan Digital Sky Survey. III. Spectropolarimetry Reveals Hidden Type I Nuclei
Hall, Patrick B.; Strauss, Michael A.; Brinkmann, J. +7 more
We have conducted spectropolarimetry of 12 type II (obscured) quasar candidates selected from the spectroscopic database of the Sloan Digital Sky Survey on the basis of their emission-line properties. Polarization was detected in all objects, with nine being highly polarized (>3%) and with polarization reaching as high as 17% in two objects. Br…
Coronal Mass Ejection Shock and Sheath Structures Relevant to Particle Acceleration
Gombosi, T. I.; Tóth, G.; Zurbuchen, T. H. +6 more
Most high-energy solar energetic particles are believed to be accelerated at shock waves driven by coronal mass ejections (CMEs). The acceleration process strongly depends on the shock geometry and the structure of the sheath that forms behind the shock. In an effort to understand the structure and time evolution of such CME-driven shocks and thei…