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Disk and Halo Wide Binaries from the Revised Luyten Catalog: Probes of Star Formation and MACHO Dark Matter
Gould, Andrew; Chanamé, Julio
We present a catalog of 1147 candidate common proper motion binaries selected from the revised New Luyten Two-Tenths Catalog (NLTT). Among these, we identify 999 genuine physical pairs using the measured proper-motion difference and the relative positions of each binary's components on a reduced proper motion (RPM) diagram. The RPM positions also …
An Unveiling Event in the Type 2 Active Galactic Nucleus NGC 4388:A Challenge for a Parsec-Scale Absorber
Fiore, F.; Elvis, Martin; Miller, J. M. +3 more
We present two Rossi X-Ray Timing Explorer (RXTE) Proportional Counter Array (PCA) observations of the type 2 Seyfert galaxy NGC 4388 caught in an unusual low X-ray absorption state. The observations were triggered by a detection in the 1.5-3 keV band of the RXTE all-sky monitor. NGC 4388 was found at a somewhat high continuum level [f(2-10 keV)=8…
Discovery of Face-on Counterparts of Chain Galaxies in the Tadpole Advanced Camera for Surveys Field
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Hirst, Amelia C.
The background field of the Tadpole galaxy image taken with the Hubble Space Telescope Advanced Camera for Surveys contains 87 clump clusters that are probably low-inclination versions of the 69 chain galaxies that we found in a previous paper. This conclusion follows from the similarity in colors and apparent magnitudes of the brightest clumps in…
Subgalactic Clumps at High Redshift: A Fragmentation Origin?
Gerhard, Ortwin; Westera, Pieter; Immeli, Andreas +1 more
We investigate the origin of the clumpy structures observed at high redshift, such as chain galaxies. We use a three-dimensional chemodynamical simulation describing the dynamics of stars and a two-phase interstellar medium, as well as feedback processes from the stars. For high efficiency of energy dissipation in the cold cloud medium, the initia…
Discovery of Hard Nonthermal Pulsed X-Ray Emission from the Anomalous X-Ray Pulsar 1E 1841-045
Kuiper, L.; Hermsen, W.; Mendez, M.
We report the discovery of nonthermal pulsed X-ray/soft gamma-ray emission up to ~150 keV from the anomalous 11.8 s X-ray pulsar AXP 1E 1841-045 located near the center of supernova remnant Kes 73 using Rossi X-Ray Timing Explorer (RXTE) Proportional Counter Array and High Energy X-Ray Timing Experiment (HEXTE) data. The morphology of the double-p…
Hubble Space Telescope Imaging and Keck Spectroscopy of z ~ 6 i-Band Dropout Galaxies in the Advanced Camera for Surveys GOODS Fields
Treu, Tommaso; Bunker, Andrew J.; McMahon, Richard G. +3 more
We measure the surface density of i'-band dropout galaxies at z~6 through wide-field Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging and ultradeep Keck DEIMOS spectroscopy. Using deep HST ACS SDSS i' (F775W) and SDSS z' (F850LP) imaging from the Great Observatories Origins Deep Survey-North (GOODS-N 200 arcmin2), …
The Relationship Between Black Hole Mass and Velocity Dispersion in Seyfert 1 Galaxies
Green, Richard F.; Gebhardt, Karl; Bower, Gary +2 more
Black hole masses in active galactic nuclei are difficult to measure using conventional dynamical methods but can be determined using the technique of reverberation mapping. However, it is important to verify that the results of these different methods are equivalent. This can be done indirectly, using scaling relations between the black hole and …
Arp 299: A Second Merging System with Two Active Nuclei?
Maraschi, L.; Ballo, L.; Tavecchio, F. +3 more
Recent BeppoSAX observations of Arp 299, a powerful far-IR merging starburst system composed of IC 694 and NGC 3690, clearly unveiled for the first time in this system the presence of a strongly absorbed active galactic nucleus (AGN). However, the system was not spatially resolved by BeppoSAX. Here we present the analysis of archival Chandra and (…
Eruption of a Multiple-Turn Helical Magnetic Flux Tube in a Large Flare: Evidence for External and Internal Reconnection That Fits the Breakout Model of Solar Magnetic Eruptions
Moore, R. L.; Gary, G. Allen
We present observations and an interpretation of a unique multiple-turn spiral flux tube eruption from active region 10030 on 2002 July 15. The TRACE C IV observations clearly show a flux tube that is helical and erupting from within a sheared magnetic field. These observations are interpreted in the context of the breakout model for magnetic fiel…
Hubble Space Telescope STIS Ultraviolet Spectral Evidence of Outflow in Extreme Narrow-Line Seyfert 1 Galaxies. I. Data and Analysis
Leighly, Karen M.; Moore, John R.
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of two extreme narrow-line Seyfert 1 galaxies (NLS1's), IRAS 13224-3809 and 1H 0707-495. The spectra are characterized by very blue continua; broad, strongly blueshifted high-ionization lines (including C IV and N V); and narrow, symmetric intermediate- (incl…