Search Publications
Search for polycyclic aromatic hydrocarbons in the Perseus molecular cloud with the Green Bank Telescope
Pérez, Laura M.; Maddalena, Ronald J.; Ali-Haïmoud, Yacine +1 more
Polycyclic aromatic hydrocarbons (PAHs) are believed to be the small-size tail of the interstellar carbonaceous dust grain population. Their vibrational emission is the most widely accepted source of the aromatic near-infrared features, and their rotational radiation is a likely explanation for the dust-correlated anomalous microwave emission (AME…
Wavelet analysis of CME, X-ray flare, and sunspot series
Pereira, E. S.; Guedes, M. R. G.; Cecatto, J. R.
Context. Coronal mass ejections (CMEs) and solar flares are the most energetic transient phenomena taking place at the Sun. Together they are principally responsible for disturbances in outer geospace. Coronal mass ejections and solar flares are believed to be correlated with the solar cycle, which is mainly characterized by sunspot numbers.
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Herschel/PACS view of disks around low-mass stars and brown dwarfs in the TW Hydrae association
Herczeg, Gregory J.; Kraus, Adam L.; Shkolnik, Evgenya L. +6 more
We conducted Herschel/PACS observations of five very low-mass stars or brown dwarfs located in the TW Hya association with the goal of characterizing the properties of disks in the low stellar mass regime. We detected all five targets at 70 µm and 100 µm and three targets at 160 µm. Our observations, combined with previous photom…
Echelle spectroscopy and photoionization modelling of the entire planetary nebula NGC 6210
Dufour, R. J.; Bohigas, J.; Rodríguez, M. +1 more
High-resolution spectroscopy of NGC 6210, show that recombination line abundances of O+2 and Ne+2 are two to three times larger than forbidden line abundances, Te(O+2) is smaller than Te(N+) and possibly Te(S+), the ionized mass is ≃0.07 M⊙ and the p…
Statistics of Langmuir wave amplitudes observed inside Saturn's foreshock by the Cassini spacecraft
Gurnett, Donald A.; Kurth, William S.; Hospodarsky, George B. +5 more
We present the first systematic study of Langmuir wave amplitudes in Saturn's foreshock using the Cassini Radio and Plasma Wave Science/Wideband Receiver measurements. We analyzed all foreshock crossings from June 2004 to December 2009 using an automatic method to identify Langmuir waves. Using this method, almost 3 × 105 waveform inter…
Phobos grooves and impact craters: A stereographic analysis
Massironi, Matteo; Pajola, Maurizio; Cremonese, Gabriele +1 more
Phobos parallel grooves were first observed on Viking images 38 years ago and since then they have been greatly debated leading to several formation hypotheses. Nevertheless, none of them have been favoured and widely accepted. In this work, we provide a different approach, assuming that Phobos grooves can be the expression of fracture planes, and…
High Energy Polarization of Blazars: Detection Prospects
Chakraborty, N.; Pavlidou, V.; Fields, B. D.
Emission from blazar jets in the ultraviolet, optical, and infrared is polarized. If these low-energy photons were inverse-Compton scattered, the upscattered high-energy photons retain a fraction of the polarization. Current and future X-ray and gamma-ray polarimeters such as INTEGRAL-SPI, PoGOLITE, X-Calibur, Gamma-Ray Burst Polarimeter, GEMS-lik…
Three-micron extinction of the Titan haze in the 250-700 km altitude range: Possible evidence of a particle-aging process
Bar-Nun, Akiva; Kim, Sang Joon; Courtin, Régis
Context. The chemical nature of the Titan haze is poorly understood. The investigation carried out by the Cassini-Huygens suite of instruments is bringing new insights into this question.
Aims: This work aims at deriving the vertical variation of the spectral structure of the 3.3-3.4 µm absorption feature of the Titan haze from Cassini …
Multiwavelength Observations of a Slow-rise, Multistep X1.6 Flare and the Associated Eruption
Cho, K. -S.; Yurchyshyn, V.; Abramenko, V. I. +2 more
Using multiwavelength observations, we studied a slow-rise, multistep X1.6 flare that began on 2014 November 7 as a localized eruption of core fields inside a δ-sunspot and later engulfed the entire active region (AR). This flare event was associated with formation of two systems of post-eruption arcades (PEAs) and several J-shaped flare ribbons s…
The Temperature Distribution of Horizontal Branch Stars: Methods and First Results
Dalessandro, E.; Salaris, M.; Lagioia, E. P. +4 more
As part of a large project aimed at characterizing the ultraviolet (UV) properties of globular clusters, we present here a theoretical and observational analysis aimed at setting the framework for the determination of horizontal branch (HB) temperature distributions. Indeed this is crucial information needed to understand the physical parameters s…