Search Publications
Ionization Mechanisms in Quasar Outflows
Veilleux, Sylvain; Rupke, David S. N.; Hinkle, Jason T.
The various ionization mechanisms at play in active galactic nuclei (AGN) and quasars have been well studied, but relatively little has been done to separately investigate the contributions of these ionization mechanisms within the host galaxy and outflowing components. Using Gemini integral field spectroscopy data, we study the ionization propert…
Dynamical masses and mass-to-light ratios of resolved massive star clusters - I. NGC 419 and NGC 1846
Mateo, Mario; Mackey, A. D.; Roederer, Ian U. +4 more
As an introduction of a kinematic survey of Magellanic Cloud (MC) star clusters, we report on the dynamical masses and mass-to-light ratios (M/L) of NGC 419 (Small Magellanic Cloud) and NGC 1846 (Large Magellanic Cloud). We have obtained more than one hundred high-resolution stellar spectra in and around each cluster using the multi-object spectro…
Resonant assisted annihilation
Nath Maity, Tarak; Sankar Ray, Tirtha
Assisted annihilation is a novel mechanism to generate viable sub-GeV thermal dark matter, where a pair of stable dark matter annihilates with an assister to Standard Model states. Typically such 3 → 2 annihilation topologies are flux suppressed compared to 2 → 2 processes. In this paper, we explore the possibility of a resonant 3 → 2 assisted ann…
Exposure Experiments of Amorphous Silicates and Organics to Cometary Ice and Vapor Analogs
Takigawa, Aki; Kimura, Yuki; Davidsson, Björn +2 more
Hydration is a major mineral alteration process in primitive asteroids and it might occur in comet nuclei; however, it is poorly understood at low temperatures, especially below the freezing point of water. Long-duration experiments were performed with exposures of amorphous silicate nanoparticles and organic compounds (glycine and ribose) to D
Liquid Water Detection under the South Polar Layered Deposits of Mars—a Probabilistic Inversion Approach
Lauro; Soldovieri; Orosei +7 more
GeV-TeV γ-rays produced by electrons in the kpc-scale jet as a result of Comptonization of the inner jet emission
Bednarek, W.
A few radio galaxies have been discovered to emit GeV-TeV γ-ray emission in spite of the relatively large viewing angles of their jets. We consider a scenario in which such large-angle γ-ray emission is preferentially produced by isotropically distributed relativistic electrons in the kpc-scale jet. These electrons Comptonize soft non-thermal radi…
The Possible Astrometric Signature of a Planetary-mass Companion to the Nearby Young Star TW Piscis Austrini (Fomalhaut B): Constraints from Astrometry, Radial Velocities, and Direct Imaging
Esposito, Thomas M.; Kalas, Paul; De Rosa, Robert J. +5 more
We present constraints on the presence of substellar companions to the nearby (d ∼ 7.6 pc) young (440 ± 40 Myr) K4Ve star TW Piscis Austrini, the wide (∼0.3 pc) companion to the A4V star Fomalhaut. We combined absolute astrometry from Hipparcos and Gaia with literature radial velocity measurements and dedicated high-contrast imaging observations o…
New CCD astrometric observations of the five major uranian satellites using Gaia DR1 in 2014-2016
Vienne, A.; Wang, N.; Peng, Q. Y. +4 more
710 CCD frames, observed by 1-m telescope at Yunnan Observatory over 15 nights, have been reduced to derive new precise positions of the five Uranian major satellites (Ariel, Umbriel, Titania, Oberon and Miranda). In the pixel positional measurement of the faint satellites near Uranus, a halo removal procedure similar to that of Veiga et al. (Veig…
Classical T-Tauri stars with VPHAS+: II: NGC 6383 in Sh 2-012
Kalari, V. M.
This paper presents optical (ugriHα)-infrared (JHKs, 3.6-8.0 µm) photometry and Gaia astrometry of 55 Classical T-Tauri stars (CTTS) in the star-forming region Sh 2-012 and its central cluster NGC 6383. The sample was identified based on photometric Hα emission linewidths, and has a median age of 2.8 ± 1.6 Myr, with a mass range between 0.3 …
X-ray properties of two transient ULX candidates in galaxy NGC 7090
O'Brien, P. T.; Osborne, J. P.; Page, K. L. +2 more
We report the X-ray data analysis of two transient ultraluminous X-ray sources (ULXs; hereafter X1 and X2) located in the nearby galaxy NGC 7090. While they were not detected in the 2004 XMM-Newton and 2005 Chandra observations, their 0.3-10 keV X-ray luminosities reached >3 × 1039 erg s-1in later XMM-Newton or Swift obser…