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A Fast Flare and Direct Redshift Constraint in Far-ultraviolet Spectra of the Blazar S5 0716+714
Danforth, Charles W.; France, Kevin; Keeney, Brian A. +1 more
The BL Lacertae object S5 0716+714 is one of the most studied blazars on the sky due to its active variability and brightness in many bands, including very-high-energy gamma rays. We present here two serendipitous results from recent far-ultraviolet spectroscopic observations by the Cosmic Origins Spectrograph onboard the Hubble Space Telescope (H…
Late origin of the Saturn system
Asphaug, Erik; Reufer, Andreas
Saturn is orbited by a half dozen ice rich middle-sized moons (MSMs) of diverse geology and composition. These comprise ∼4.4% of Saturn’s satellite mass; the rest is Titan, more massive per planet than Jupiter’s satellites combined. Jupiter has no MSMs. Disk-based models to explain these differences exist, but have various challenges and assumptio…
Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuSTAR: Compton-thick Absorption or Intrinsic X-Ray Weakness?
Harrison, F. A.; Stern, D.; Zhang, W. W. +22 more
We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are amo…
CANDELS Observations of the Environmental Dependence of the Color-Mass-Morphology Relation at z = 1.6
Papovich, Casey; Finkelstein, Steven L.; Bell, Eric F. +16 more
We study the environmental dependence of color, stellar mass, and morphology by comparing galaxies in a forming cluster to those in the field at z = 1.6 with Hubble Space Telescope near-infrared imaging in the CANDELS/UDS field. We quantify the morphology of the galaxies using the effective radius, r eff, and Sérsic index, n. In both th…
Photometric properties of the nucleus of Comet 103P/Hartley 2
A'Hearn, Michael F.; Thomas, Peter C.; Bodewits, Dennis +8 more
We have studied the photometric properties of the nucleus of a hyperactive comet, 103P/Hartley 2, at visible wavelengths using the DIXI flyby images with both disk-integrated and disk-resolved analyses. The disk-integrated phase function of the nucleus has a linear slope of 0.046 ± 0.002 mag/deg and an absolute magnitude of 18.4 ± 0.1 at V-band. T…
A complete climatology of the aerosol vertical distribution on Mars from MEx/SPICAM UV solar occultations
Montmessin, Franck; Bertaux, Jean-Loup; Maltagliati, Luca +4 more
We present the first results on solar occultations performed with the UV channel of SPICAM, on board Mars Express. From the dataset of over 900 occultations (performed between April 2004 and October 2011), about 640 atmospheric profiles of the martian atmosphere were derived. This dataset, spanning four martian years, allows characterization of th…
Derivation of the Magnetic Field in a Coronal Mass Ejection Core via Multi-frequency Radio Imaging
Vourlidas, A.; Tun, Samuel D.
The magnetic field within the core of a coronal mass ejection (CME) on 2010 August 14 is derived from analysis of multi-wavelength radio imaging data. This CME's core was found to be the source of a moving type IV radio burst, whose emission is here determined to arise from the gyrosynchrotron process. The CME core's true trajectory, electron dens…
The insignificance of Major mergers in driving star formation at z =~ 2.
O'Connell, R. W.; Dekel, A.; Hathi, N. P. +7 more
We study the significance of major-merger-driven star formation in the early Universe, by quantifying the contribution of this process to the total star formation budget in 80 massive (M* > 1010 M⊙) galaxies at z ≃ 2. Employing visually classified morphologies from rest-frame V-band Hubble Space Telescope (HST) …
The SEEDS Direct Imaging Survey for Planets and Scattered Dust Emission in Debris Disk Systems
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +49 more
Debris disks around young main-sequence stars often have gaps and cavities which for a long time have been interpreted as possibly being caused by planets. In recent years, several giant planet discoveries have been made in systems hosting disks of precisely this nature, further implying that interactions with planets could be a common cause of su…
Survey of cometary CO2, CO, and particulate emissions using the Spitzer Space Telescope
Reach, William T.; Kelley, Michael S.; Vaubaillon, Jeremie
We surveyed 23 comets using the Infrared Array Camera on the Spitzer Space Telescope in wide filters centered at 3.6 and 4.5 µm. Emission in the 3.6 µm filter arises from sunlight scattered by dust grains; the 3.6 µm images generally have a coma near the nucleus and a tail in the antisolar direction due to dust grains swept back …