Search Publications
Constraining the Spin-down of the Nearby Isolated Neutron Star RX J0806.4-4123, and Implications for the Population of Nearby Neutron Stars
van Kerkwijk, M. H.; Kaplan, D. L.
The nearby isolated neutron stars (INSs) are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine fundamental neutron-star properties by modeling their spectra, and because they appear to be a large fraction …
Ultraviolet Spectroscopy of Supernovae: The First Two Years of Swift Observations
Panagia, N.; Pian, E.; Gehrels, N. +13 more
We present the entire sample of ultraviolet (UV) spectra of supernovae (SNe) obtained with the Ultraviolet/Optical Telescope (UVOT) on board the Swift satellite during the first two years of observations (2005/2006). A total of 29 UV-grism and 22 V-grism spectra of nine SNe have been collected, of which six are thermonuclear (Type Ia) and three co…
Automated Detection of Galaxy-Scale Gravitational Lenses in High-Resolution Imaging Data
Bradač, Maruša; Hogg, David W.; Marshall, Philip J. +4 more
We expect direct lens modeling to be the key to successful and meaningful automated strong galaxy-scale gravitational lens detection. We have implemented a lens-modeling "robot" that treats every bright red galaxy (BRG) in a large imaging survey as a potential gravitational lens system. Having optimized a simple model for "typical" galaxy-scale gr…
The Expanding Nebular Remnant of the Recurrent Nova RS Ophiuchi (2006). II. Modeling of Combined Hubble Space Telescope Imaging and Ground-based Spectroscopy
Chavushyan, V. H.; Zharikov, S. V.; Eyres, S. P. S. +16 more
We report Hubble Space Telescope (HST) imaging, obtained 155 and 449 days after the 2006 outburst of the recurrent nova RS Ophiuchi, together with ground-based spectroscopic observations, obtained from the Observatorio Astronómico Nacional en San Pedro Mártir, Baja California, México and at the Observatorio Astrofísico Guillermo Haro, at Cananea, …
A "Firework" of H2 Knots in the Planetary Nebula NGC 7293 (The Helix Nebula)
Smith, M. D.; Tanaka, I.; Zijlstra, A. A. +6 more
We present a deep and wide field-of-view (4' × 7') image of the planetary nebula (PN) NGC 7293 (the Helix Nebula) in the 2.12 µm H2 v = 1 → 0 S(1) line. The excellent seeing (0farcs4) at the Subaru Telescope, allows the details of cometary knots to be examined. The knots are found at distances of 2farcm2-6farcm4 from the central s…
Detection of Water Ice Grains on the Surface of the Circumstellar Disk Around HD 142527
Tamura, M.; Ishii, M.; Kudo, T. +11 more
Coronagraphic imaging for the Herbig Ae star, HD 142527, was performed using the Coronagraphic Imager with Adaptive Optics (CIAO) on the 8.2 m Subaru Telescope. The images were obtained in the H2O ice filter (λ = 3.08 µm) using adaptive optics (AO), and in the L' band without AO. Combining these data with previous observational re…
NTT, Spitzer, and Chandra Spectroscopy of SDSSJ095209.56+214313.3: The Most Luminous Coronal-line Supernova Ever Observed, or a Stellar Tidal Disruption Event?
Greiner, J.; Gal-Yam, A.; Salvato, M. +9 more
The galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter) showed remarkable emission-line and continuum properties and strong emission-line variability first reported in 2008 (Paper I). The spectral properties and low-energy variability are the consequence of a powerful high-energy flare which was itself not observed directly. Here we report f…
Modulation of Galactic Cosmic Ray Protons and Electrons During an Unusual Solar Minimum
Fichtner, H.; Scherer, K.; Ferreira, S. E. S. +5 more
During the latest Ulysses out-of-ecliptic orbit the solar wind density, pressure, and magnetic field strength have been the lowest ever observed in the history of space exploration. Since cosmic ray particles respond to the heliospheric magnetic field in the expanding solar wind and its turbulence, the weak heliospheric magnetic field as well as t…
The Physical Properties and Effective Temperature Scale of O-Type Stars as a Function of Metallicity. III. More Results From the Magellanic Clouds
Massey, Philip; Bresolin, Fabio; Kudritzki, Rolf-Peter +4 more
In order to better determine the physical properties of hot, massive stars as a function of metallicity, we obtained very high signal-to-noise ratio optical spectra of 26 O and early B stars in the Magellanic Clouds. These allow accurate modeling even in cases where the He I λ4471 line has an equivalent width of only a few tens of m Å. The spectra…
Spatially Resolved Spectroscopy of Sub-AU-Sized Regions of T Tauri and Herbig Ae/Be Disks
Najita, J.; Eisner, J. A.; Graham, J. R. +1 more
We present spatially resolved near-IR spectroscopic observations of 15 young stars. Using a grism spectrometer behind the Keck interferometer, we obtained an angular resolution of a few milliarcseconds and a spectral resolution of 230, enabling probes of both gas and dust in the inner disks surrounding the target stars. We find that the angular si…