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Origin and Evolution of the Cometary Reservoirs
Dones, Luke; Brasser, Ramon; Kaib, Nathan +1 more
Comets have three known reservoirs: the roughly spherical Oort Cloud (for long-period comets), the flattened Kuiper Belt (for ecliptic comets), and, surprisingly, the asteroid belt (for main-belt comets). Comets in the Oort Cloud were thought to have formed in the region of the giant planets and then placed in quasi-stable orbits at distances of t…
Comet 67P/Churyumov-Gerasimenko sheds dust coat accumulated over the past four years
Langevin, Yves; Fischer, Henning; Briois, Christelle +22 more
Comets are composed of dust and frozen gases. The ices are mixed with the refractory material either as an icy conglomerate, or as an aggregate of pre-solar grains (grains that existed prior to the formation of the Solar System), mantled by an ice layer. The presence of water-ice grains in periodic comets is now well established. Modelling of infr…
First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background
Follin, Brent; Knox, Lloyd; Millea, Marius +1 more
The unimpeded relativistic propagation of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which…
The MOSDEF Survey: Optical Active Galactic Nucleus Diagnostics at z ~ 2.3
Siana, Brian; Shapley, Alice E.; Aird, James +7 more
We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on rest-frame optical active galactic nucleus (AGN) identification and completeness at z ~ 2.3. With our sample of 50 galaxies and 10 X-ray and IR-selected AGNs with measured Hβ, [O III], Hα, and N II emission lines, we investigate the location of AGNs in the BPT, MEx (mass-e…
Measurements of Sub-degree B-mode Polarization in the Cosmic Microwave Background from 100 Square Degrees of SPTpol Data
Ade, P. A. R.; Chiang, H. C.; Hanson, D. +63 more
We present a measurement of the B-mode polarization power spectrum (the BB spectrum) from 100 {{deg}}2 of sky observed with SPTpol, a polarization-sensitive receiver currently installed on the South Pole Telescope. The observations used in this work were taken during 2012 and early 2013 and include data in spectral bands centered at 95 …
Supercal: Cross-calibration of Multiple Photometric Systems to Improve Cosmological Measurements with Type Ia Supernovae
Rest, A.; Foley, R. J.; Kudritzki, R. P. +16 more
Current cosmological analyses, which use Type Ia supernova observations, combine supernova (SN) samples to expand the redshift range beyond that of a single sample and increase the overall sample size. The inhomogeneous photometric calibration between different SN samples is one of the largest systematic uncertainties of the cosmological parameter…
Two independent and primitive envelopes of the bilobate nucleus of comet 67P
Bertaux, Jean-Loup; Naletto, Giampiero; Debei, Stefano +56 more
The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the inte…
The Role of Star Formation and an AGN in Dust Heating of z = 0.3-2.8 Galaxies. I. Evolution with Redshift and Luminosity
Kirkpatrick, Allison; Pope, Alexandra; Díaz-Santos, Tanio +5 more
We characterize infrared spectral energy distributions of 343 (ultra)luminous infrared galaxies from z = 0.3-2.8. We diagnose the presence of an active galactic nucleus (AGN) by decomposing individual Spitzer mid-IR spectroscopy into emission from star formation and an AGN-powered continuum; we classify sources as star-forming galaxies (SFGs), AGN…
A tidal disruption flare in a massive galaxy? Implications for the fuelling mechanisms of nuclear black holes
Greiner, J.; Georgakakis, A.; Salvato, M. +6 more
We argue that the `changing look' active galactic nucleus (AGN) recently reported by LaMassa et al. could be a luminous flare produced by the tidal disruption of a supersolar mass star passing just a few gravitational radii outside the event horizon of a ∼108 M⊙ nuclear black hole. This flare occurred in a massive, star-formi…
The nature of the [C II] emission in dusty star-forming galaxies from the SPT survey
Béthermin, M.; Murphy, E. J.; Greve, T. R. +24 more
We present [C II] observations of 20 strongly lensed dusty star-forming galaxies at 2.1 < z < 5.7 using Atacama Pathfinder EXperiment and Herschel. The sources were selected on their 1.4 mm flux (S1.4 mm > 20 mJy) from the South Pole Telescope (SPT) survey, with far-infrared (FIR) luminosities determined from extensive photomet…