Search Publications
The effect of frame dragging on the iron Kα line in X-ray binaries
Ingram, Adam; Done, Chris
The clear characteristic time-scale picked out by the low-frequency quasi-periodic oscillations (QPOs) seen in many black hole and neutron star binaries has the potential to provide a very powerful diagnostic of the inner regions of the accretion flow. However, this potential cannot be realized without a quantitative model for the QPO. We have rec…
A Type Ia Supernova at Redshift 1.55 in Hubble Space Telescope Infrared Observations from CANDELS
Ferguson, Henry C.; Grogin, Norman A.; Weiner, Benjamin J. +23 more
We report the discovery of a Type Ia supernova (SN Ia) at redshift z = 1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field and followed as part of the CANDELS+CLASH Supernova project, comprising the SN search comp…
The Three-dimensional Distribution of Dust in NGC 891
Bershady, Matthew A.; Schechtman-Rook, Andrew; Wood, Kenneth
We produce three-dimensional Monte Carlo radiative transfer models of the edge-on spiral galaxy NGC 891, a fast-rotating galaxy thought to be an analog to the Milky Way. The models contain realistic spiral arms and a fractal distribution of clumpy dust. We fit our models to Hubble Space Telescope images corresponding to the B and I bands, using sh…
Time-resolved spectroscopy of BD+46°442: Gas streams and jet creation in a newly discovered evolved binary with a disk
Jorissen, A.; Frémat, Y.; Gorlova, N. +9 more
Context. Previous studies have shown that many post-asymptotic giant branch (AGB) stars with dusty disks are associated with single-lined binary stars. The inferred orbital separations are too small to accommodate a fully grown AGB star, hence these systems represent a new evolutionary channel that bypasses a full AGB evolution.
Aims: We wish…
Discovery and Early Multi-wavelength Measurements of the Energetic Type Ic Supernova PTF12gzk: A Massive-star Explosion in a Dwarf Host Galaxy
Vanderburg, Andrew; Filippenko, Alexei V.; Cenko, S. Bradley +46 more
We present the discovery and extensive early-time observations of the Type Ic supernova (SN) PTF12gzk. Our light curves show a rise of 0.8 mag within 2.5 hr. Power-law fits (f(t)vprop(t - t 0) n ) to these data constrain the explosion date to within one day. We cannot rule out a quadratic fireball model, but higher values of …
Observations of the near- to Mid-infrared Unidentified Emission Bands in the Interstellar Medium of the Large Magellanic Cloud
Onaka, Takashi; Sakon, Itsuki; Kaneda, Hidehiro +3 more
We present the results of near- to mid-infrared slit spectroscopic observations (2.55-13.4 µm) of the diffuse emission toward nine positions in the Large Magellanic Cloud with the infrared camera on board AKARI. The target positions are selected to cover a wide range of the intensity of the incident radiation field. The unidentified infrared…
Water Ice in the Kuiper Belt
Brown, M. E.; Schaller, E. L.; Fraser, W. C.
We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice…
The CHESS survey of the L1157-B1 shock: the dissociative jet shock as revealed by Herschel-PACS
Codella, C.; Ceccarelli, C.; Benedettini, M. +9 more
Outflows generated by protostars heavily affect the kinematics and chemistry of the hosting molecular cloud through strong shocks that enhance the abundance of some molecules. L1157 is the prototype of chemically active outflows, and a strong shock, called B1, is taking place in its blue lobe between the precessing jet and the hosting cloud. We pr…
Supernova Remnant Progenitor Masses in M31
Dolphin, Andrew E.; Williams, Benjamin F.; Gilbert, Karoline M. +5 more
Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M ZAMS) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the r…
COSMOS: Stochastic Bias from Measurements of Weak Lensing and Galaxy Clustering
Massey, Richard; Kneib, Jean-Paul; Rhodes, Jason +6 more
In the theory of structure formation, galaxies are biased tracers of the underlying matter density field. The statistical relation between galaxy and matter density field is commonly referred to as galaxy bias. In this paper, we test the linear bias model with weak-lensing and galaxy clustering measurements in the 2 deg2 COSMOS field. W…