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UBVR and Hubble Space Telescope Mid-Ultraviolet and Near-Infrared Surface Photometry and Radial Color Gradients of Late-Type, Irregular, and Peculiar Galaxies
Windhorst, Rogier A.; Jansen, Rolf A.; Hibbard, John E. +2 more
We introduce a data set of 142 mostly late-type spiral, irregular, and peculiar (interacting or merging) nearby galaxies observed in UBVR at the Vatican Advanced Technology Telescope (VATT), and we present an analysis of their radial color gradients. We confirm that nearby elliptical and early- to mid-type spiral galaxies show either no or only sm…
X-Ray Observations of the Boundary Layer in Dwarf Novae at Low Accretion Rates
Pandel, Dirk; Mason, Keith O.; Córdova, France A. +1 more
We present a spectral analysis of XMM-Newton data of 10 dwarf novae, 9 of which were observed during a quiescent state. The X-ray spectra indicate the presence of a hot, optically thin plasma with a temperature distribution consistent with a simple, isobaric cooling flow. The likely origin of the X-ray emission is cooling plasma in the boundary la…
A Large X-Ray Outburst in Mira A
Wood, Brian E.; Schlegel, Eric; Raymond, John C. +2 more
We report the Chandra ACIS-S detection of a bright soft X-ray transient in the Mira AB interacting symbiotic-like binary. We have resolved the system for the first time in X-rays. Using Chandra and Hubble Space Telescope images, we determine that the unprecedented outburst is likely associated with the cool asymptotic giant branch (AGB) star, Mira…
Dynamical Masses for Low-Mass Pre-Main-Sequence Stars: A Preliminary Physical Orbit for HD 98800 B
Torres, Guillermo; Latham, David W.; Wasserman, Lawrence H. +7 more
We report on Keck Interferometer observations of the double-lined binary (B) component of the quadruple pre-main-sequence (PMS) system HD 98800. With these interferometric observations, combined with astrometric measurements made by the Hubble Space Telescope (HST) Fine Guidance Sensors (FGS) and published radial velocity observations, we have est…
Blue Luminous Stars in Nearby Galaxies: Quantitative Spectral Analysis of M33 B-Type Supergiant Stars
Smartt, S. J.; Lennon, D. J.; Herrero, A. +5 more
We present the detailed spectral analysis of a sample of M33 B-type supergiant stars, aimed at the determination of their fundamental parameters and chemical composition. The analysis is based on a grid of non-LTE metal line-blanketed model atmospheres including the effects of stellar winds and spherical extension computed with the code FASTWIND. …
Stellar and Total Mass in Early-Type Lensing Galaxies
Saha, Prasenjit; Ferreras, Ignacio; Williams, Liliya L. R.
For 18 well-observed gravitationally lensed QSOs, we compare new nonparametric mass profiles for the lensing galaxies with stellar population models derived from published Hubble Space Telescope photometry. The large volume of parameter space searched-with respect to the possible star formation histories-allows us to infer robust estimates and unc…
A Chandra HETGS Spectral Study of the Iron K Bandpass in MCG -6-30-15: A Narrow View of the Broad Iron Line
Young, A. J.; Fabian, A. C.; Reynolds, C. S. +3 more
We present a high-resolution X-ray spectrum of the iron K bandpass in MCG -6-30-15 based on a 522 ks observation with Chandra's High Energy Transmission Grating Spectrometer (HETGS). The Chandra spectrum is consistent with the presence of a relativistically broadened, highly redshifted iron Kα emission line with a profile similar to previous obser…
Kinematics of Low-z Ultraluminous Infrared Galaxies and Implications for Dynamical Mass Derivations in High-z Star-forming Galaxies
Arribas, Santiago; Colina, Luis; Monreal-Ibero, A.
The kinematic properties of the gaseous and stellar components of 11 ultraluminous infrared galaxies (ULIRGs; 14 nuclei) are investigated by means of integral field spectroscopy (IFS) with the INTEGRAL system and available IR and CO millimeter spectroscopy. The sample of ULIRGs cover different phases of the merging process and span all levels of a…
Predicting QSO Continua in the Lyα Forest
O'Meara, John M.; Tytler, David; Lubin, Dan +2 more
We present a method to make predictions with sets of correlated data values, in this case QSO flux spectra. We predict the continuum in the Lyα forest of a QSO, from 1020 to 1216 Å, using the spectrum of that QSO from 1216 to 1600 Å. We find correlations between the unabsorbed flux in these two wavelength regions in the Hubble Space Telescope (HST…
The Fundamental Plane of Cluster Elliptical Galaxies at z=1.25
Rosati, P.; Rix, H. -W.; van der Wel, A. +8 more
Using deep Hubble Space Telescope Advanced Camera for Surveys imaging and Very Large Telescope FOcal Reducer/low dispersion Spectrograph 2 spectra, we determined the velocity dispersions, effective radii, and surface brightnesses for four early-type galaxies in the z=1.237 cluster RDCS 1252.9-2927. All four galaxies are massive, greater than 10