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Carbon-rich Dust Past the Asymptotic Giant Branch: Aliphatics, Aromatics, and Fullerenes in the Magellanic Clouds
Sahai, R.; Zijlstra, A. A.; Peeters, E. +10 more
Infrared spectra of carbon-rich objects that have evolved off the asymptotic giant branch reveal a range of dust properties, including fullerenes, polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, and several unidentified features, including the 21 µm emission feature. To test for the presence of fullerenes, we used the positi…
The INTEGRAL High-energy Cut-off Distribution of Type 1 Active Galactic Nuclei
Bird, A. J.; Ubertini, P.; Malizia, A. +4 more
In this Letter we present the primary continuum parameters, the photon index Γ, and the high-energy cut-off E c of 41 type-1 Seyfert galaxies extracted from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) complete sample of active galactic nuclei (AGNs). We performed broadband (0.3-100 keV) spectral analysis by simultaneo…
Multifield inflation after Planck: Isocurvature modes from nonminimal couplings
Schutz, Katelin; Sfakianakis, Evangelos I.; Kaiser, David I.
Recent measurements by the Planck experiment of the power spectrum of temperature anisotropies in the cosmic microwave background radiation reveal a deficit of power in low multipoles compared to the predictions from best-fit ΛCDM cosmology. If the low-ℓ anomaly persists after additional observations and analysis, it might be explained by the pres…
Disintegrating Asteroid P/2013 R3
Mutchler, Max; Jewitt, David; Agarwal, Jessica +3 more
Splitting of the nuclei of comets into multiple components has been frequently observed but, to date, no main-belt asteroid has been observed to break up. Using the Hubble Space Telescope, we find that main-belt asteroid P/2013 R3 consists of 10 or more distinct components, the largest up to 200 m in radius (assumed geometric albedo of 0.05) each …
Inflation with Whip-Shaped Suppressed Scalar Power Spectra
Starobinsky, Alexei A.; Hazra, Dhiraj Kumar; Smoot, George F. +1 more
Motivated by the idea that inflation occurs at the grand unified theory symmetry breaking scale, in this Letter we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after an initial period of relatively fast roll that lasts until after a few e folds inside the horizon it transits to the …
Exploring the full parameter space for an interacting dark energy model with recent observations including redshift-space distortions: Application of the parametrized post-Friedmann approach
Zhang, Jing-Fei; Zhang, Xin; Li, Yun-He
Dark energy can modify the dynamics of dark matter if there exists a direct interaction between them. Thus, a measurement of the structure growth, e.g., redshift-space distortions (RSDs), can provide a powerful tool to constrain the interacting dark energy (IDE) models. For the widely studied Q =3 β H ρde model, previous works showed th…
The Light Curve of SN 1987A Revisited: Constraining Production Masses of Radioactive Nuclides
Seitenzahl, Ivo R.; Timmes, F. X.; Magkotsios, Georgios
We revisit the evidence for the contribution of the long-lived radioactive nuclides 44Ti, 55Fe, 56Co, 57Co, and 60Co to the UVOIR light curve of SN 1987A. We show that the V-band luminosity constitutes a roughly constant fraction of the bolometric luminosity between 900 and 1900 days, and we o…
NuSTAR and XMM-NEWTON Observations of NGC 1365: Extreme Absorption Variability and a Constant Inner Accretion Disk
Harrison, F. A.; Stern, D.; Zhang, W. W. +24 more
We present a spectral analysis of four coordinated NuSTAR+XMM-Newton observations of the Seyfert galaxy NGC 1365. These exhibit an extreme level of spectral variability, which is primarily due to variable line-of-sight absorption, revealing relatively unobscured states in this source for the first time. Despite the diverse range of absorption stat…
Weak Hard X-Ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-Ray Weakness
Harrison, F. A.; Stern, D.; Zhang, W. W. +19 more
We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z < 1.3. However, their rest-frame ≈2 keV luminosities are 14 to >330 times weaker than expected for typical quasars. Our results from a p…
Hubble Space Telescope CALSPEC Flux Standards: Sirius (and Vega)
Bohlin, R. C.
The Space Telescope Imaging Spectrograph (STIS) has measured the flux for Sirius from 0.17 to 1.01 µm on the Hubble Space Telescope (HST) White Dwarf scale. Because of the cool debris disk around Vega, Sirius is commonly recommended as the primary IR flux standard. The measured STIS flux agrees well with predictions of a special Kurucz model…