Search Publications
Mapping Extremely Low Metallicity Galaxies to Redshift One
Cowie, Lennox L.; Hu, Esther M.; Kakazu, Yuko
We describe the results of a narrowband search for ultrastrong emission line galaxies (USELs) with EW(Hβ)>=30 Å. A total of 542 candidate galaxies are found in a one-half square degree survey using two ~120 Å filters centered at 8150 and 9140 Å with Subaru SuprimeCam. Follow-up spectroscopy for randomly selected objects in the candidate sample …
Long-Term Evolution of Massive Black Hole Binaries. III. Binary Evolution in Collisional Nuclei
Merritt, David; Mikkola, Seppo; Szell, Andras
In galactic nuclei with sufficiently short relaxation times, binary supermassive black holes can evolve beyond their stalling radii via continued interaction with stars. We study this ``collisional'' evolutionary regime using both fully self-consistent N-body integrations and approximate Fokker-Planck models. The N-body integrations employ particl…
A Very Bright, Highly Magnified Lyman Break Galaxy at z = 3.07
Kneib, J. -P.; Smith, G. P.; Smail, Ian +8 more
Using Hubble Space Telescope imaging and Keck spectroscopy, we report the discovery of a very bright, highly magnified (~30 times) Lyman break galaxy (LBG) at z=3.07 in the field of the massive z=0.33 cluster MACS J2135.2-0102. The system comprises two high surface brightness arcs with a maximum extent of 3", bracketing a central object that we id…
Cassini States with Dissipation: Why Obliquity Tides Cannot Inflate Hot Jupiters
Fabrycky, Daniel C.; Johnson, Eric T.; Goodman, Jeremy
Some short-period exoplanets (``hot Jupiters'') are observed by their transits to have anomalously large radii. It has been suggested that these planets are in a resonance involving persistent misalignment and synchronous precession of their spin and orbital angular momenta (a Cassini state) and that the attendant tidal heating inflates the planet…
Collimation, Proper Motions, and Physical Conditions in the HH 30 Jet from Hubble Space Telescope Slitless Spectroscopy
Hartigan, Patrick; Morse, Jon
We present STIS spectral images of the HH 30 stellar jet taken through a wide slit over two epochs. The jet is unresolved spectrally, so the observations produce emission-line images for each line in the spectrum. This rich data set shows how physical conditions in the jet vary with distance and time, produces precise proper motions of knots withi…
A Detailed Study of Gas and Star Formation in a Highly Magnified Lyman Break Galaxy at z = 3.07
Kneib, J. -P.; Smail, Ian; Dye, S. +10 more
We report the detection of CO(3-2) emission from a bright, gravitationally lensed Lyman Break galaxy, LBG J213512.73-010143 (the ``Cosmic Eye''), at z=3.07, using the Plateau de Bure Interferometer. This is only the second detection of molecular gas emission from an LBG and yields an intrinsic molecular gas mass of (2.4+/-0.4)×109 M
Evidence of Superdiffusive Transport of Electrons Accelerated at Interplanetary Shocks
Perri, S.; Zimbardo, G.
We study the transport properties of energetic electrons accelerated at corotating interaction regions in the solar wind considering the possibility of anomalous diffusion. It is shown that the particle time decay has a power-law behavior when a non-Gaussian propagator, appropriate for superdiffusive transport, is assumed for particles accelerated…
The Post-Burst Awakening of the Anomalous X-Ray Pulsar in Westerlund 1
Campana, S.; Stella, L.; Israel, G. L. +4 more
On 2006 September 21, an intense (~1039 erg s-1) and short (20 ms) burst was detected by Swift BAT at a position consistent with that of the candidate anomalous X-ray pulsar (AXP) CXOU J164710.2-455216, discovered by Chandra in 2005. Swift follow-up observations began ~13 hr after the event and found the source at a 1-10 keV …
Mass Outflow from the Nucleus of the Seyfert 1 Galaxy NGC 4151
Kraemer, S. B.; Crenshaw, D. M.
We present an analysis of UV and optical spectra of NGC 4151 obtained at high spectral and angular resolutions with the Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS). We identify a kinematic component of the emission lines that has a width of 1170 km s-1 (FWHM), intermediate between those from the broad and narr…
η Carinae across the 2003.5 Minimum: Spectroscopic Evidence for Massive Binary Interactions
Gull, T. R.; Nielsen, K. E.; Corcoran, M. F. +4 more
We have analyzed high spatial, moderate spectral resolution observations of η Carinae (η Car) obtained with the STIS from 1998.0 to 2004.3. The data were obtained at discrete times covering an entire 2024 day spectroscopic cycle, with focus on the X-ray/ionization low state that began in 2003 June. The spectra show prominent P Cygni lines in H I, …