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Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. IV. Results of the 2014 Follow-up Campaign
Stern, D.; Smith, Howard A.; Masetti, N. +7 more
The extragalactic γ-ray sky is dominated by the emission arising from blazars, one of the most peculiar classes of radio-loud active galaxies. Since the launch of Fermi several methods were developed to search for blazars as potential counterparts of unidentified γ-ray sources (UGSs). To confirm the nature of the selected candidates, optical spect…
Asymmetric magnetic reconnection with a flow shear and applications to the magnetopause
Drake, J. F.; Eriksson, S.; Wilder, F. D. +3 more
We perform a systematic theoretical and numerical study of antiparallel two-dimensional magnetic reconnection with asymmetries in the plasma density and reconnecting magnetic field strength in addition to a bulk flow shear across the reconnection site in the plane of the reconnecting fields, which commonly occurs at planetary magnetospheres. We an…
A Connection between Obscuration and Star Formation in Luminous Quasars
Gorjian, Varoujan; Alberts, Stacey; Jones, Christine +16 more
We present a measurement of the star formation properties of a uniform sample of mid-IR-selected, optically unobscured, and obscured quasars (QSO1s and QSO2s) in the Boötes survey region. We use a spectral energy distribution analysis for photometric data spanning optical to far-IR wavelengths to separate the active galactic nucleus (AGN) and host…
The Composition of Interstellar Grains toward ζ Ophiuchi: Constraining the Elemental Budget near the Diffuse-dense Cloud Transition
Draine, Bruce T.; Poteet, Charles A.; Whittet, Douglas C. B.
We investigate the composition of interstellar grains along the line of sight toward ζ Ophiuchi, a well-studied environment near the diffuse-dense cloud transition. A spectral decomposition analysis of the solid-state absorbers is performed using archival spectroscopic observations from the Spitzer Space Telescope and Infrared Space Observatory. W…
Frontier Fields: Combining HST, VLT, and Spitzer data to explore the z ~ 8 Universe behind the lensing cluster MACSJ0416.1-2403
Pérez-Fournon, I.; Laporte, N.; Infante, L. +7 more
Context. The Hubble Space Telescope (HST) Frontier Fields (HFFs) project started at the end of 2013 with the aim of providing extremely deep images of six massive galaxy clusters. One of the main goals of this program is to push several telescopes to their limits to provide the best current view of the earliest stages of the Universe. The analysis…
Possible link between the power spectrum of interstellar filaments and the origin of the prestellar core mass function
Hill, T.; André, Ph.; Arzoumanian, D. +17 more
A complete understanding of the origin of the prestellar core mass function (CMF) is crucial. Two major features of the prestellar CMF are 1) a broad peak below 1 M⊙, presumably corresponding to a mean gravitational fragmentation scale, and 2) a characteristic power-law slope, very similar to the Salpeter slope of the stellar initial ma…
Processing results of digitized photographic observations of Pluto from the collections of the Ukrainian Virtual Observatory
Andruk, V. M.; Shatokhina, S. V.; Protsyuk, Yu. I. +2 more
The catalogue of 59 equatorial coordinates and magnitudes of the Pluto-Charon system for the period 1961–1990 was created based on digitized photographic observations from collections of the Joint Digital Archive of the Ukrainian Virtual Observatory obtained from five telescopes of three Ukrainian observatories. Developed software and scan process…
Seismic sensitivity to sub-surface solar activity from 18 yr of GOLF/SoHO observations
García, R. A.; Turck-Chièze, S.; Salabert, D.
Solar activity has significantly changed over the last two Schwabe cycles. After a long and deep minimum at the end of Cycle 23, the weaker activity of Cycle 24 contrasts with the previous cycles. In this work, the response of the solar acoustic oscillations to solar activity is used in order to provide insights into the structural and magnetic ch…
Fermi-LAT Observations of High- and Intermediate-velocity Clouds: Tracing Cosmic Rays in the Halo of the Milky Way
Marshall, D. J.; Orlando, E.; Strong, A. W. +10 more
It is widely accepted that cosmic rays (CRs) up to at least PeV energies are Galactic in origin. Accelerated particles are injected into the interstellar medium where they propagate to the farthest reaches of the Milky Way, including a surrounding halo. The composition of CRs coming to the solar system can be measured directly and has been used to…
Ensemble Modeling of the 23 July 2012 Coronal Mass Ejection
Arge, C. N.; Henney, C. J.; Odstrcil, D. +5 more
On 23 July 2012 a significant and rapid coronal mass ejection (CME) was detected in situ by the Solar Terrestrial Relations Observatory (STEREO) A. This CME was unusual due to its extremely brief Sun-to-1 AU transit time of less than 21 h and its exceptionally high impact speed of 2246 km/s. If this CME had been Earth directed, it would have produ…