Search Publications
Vaex: big data exploration in the era of Gaia
Veljanoski, Jovan; Breddels, Maarten A.
We present a new Python library, called vaex, intended to handle extremely large tabular datasets such as astronomical catalogues like the Gaia catalogue, N-body simulations, or other datasets which can be structured in rows and columns. Fast computations of statistics on regular N-dimensional grids allows analysis and visualization in the order o…
Detecting Black Hole Binaries by Gaia
Bulik, Tomasz; Piran, Tsvi; Kawanaka, Norita +1 more
We study the prospects of the Gaia satellite to identify black hole (BH) binary systems by detecting the orbital motion of the companion stars. Taking into account the initial mass function, mass transfer, common envelope phase, interstellar absorption, and identifiability of the systems, we estimate the number of BH binaries that can be detected …
Updated tomographic analysis of the integrated Sachs-Wolfe effect and implications for dark energy
Bilicki, Maciej; Lesgourgues, Julien; Cuoco, Alessandro +1 more
We derive updated constraints on the integrated Sachs-Wolfe (ISW) effect through cross-correlation of the cosmic microwave background with galaxy surveys. We improve with respect to similar previous analyses in several ways. First, we use the most recent versions of extragalactic object catalogs, SDSS DR12 photometric redshift (photo-z ) and 2MASS…
Application of the Deep Convolutional Neural Network to the Forecast of Solar Flare Occurrence Using Full-disk Solar Magnetograms
Moon, Yong-Jae; Lim, Daye; Lee, Harim +4 more
In this study, we present the application of the Convolutional Neural Network (CNN) to the forecast of solar flare occurrence. For this, we consider three CNN models (two pretrained models, AlexNet and GoogLeNet, and one newly proposed model). Our inputs are SOHO/Michelson Doppler Imager (from 1996 May to 2010 December) and SDO/Helioseismic and Ma…
ALMA Observations of Molecular Clouds in Three Group-centered Elliptical Galaxies: NGC 5846, NGC 4636, and NGC 5044
Brighenti, Fabrizio; Mathews, William G.; Temi, Pasquale +4 more
We present new ALMA CO(2-1) observations of two well-studied group-centered elliptical galaxies: NGC 4636 and NGC 5846. In addition, we include a revised analysis of Cycle 0 ALMA observations of the central galaxy in the NGC 5044 group. We find evidence that molecular gas is a common presence in bright group-centered galaxies (BGG). CO line widths…
The Pristine survey IV: approaching the Galactic metallicity floor with the discovery of an ultra-metal-poor star
Fouesneau, Morgan; Sestito, Federico; McConnachie, Alan W. +22 more
The early Universe presented a star formation environment that was almost devoid of heavy elements. The lowest metallicity stars thus provide a unique window into the earliest Galactic stages, but are exceedingly rare and difficult to find. Here, we present the discovery of an ultra-metal-poor star, Pristine_221.8781+9.7844, using narrow-band Ca H…
Sixty Validated Planets from K2 Campaigns 5-8
Henning, Thomas; Tamura, Motohide; Schlieder, Joshua E. +13 more
We present a uniform analysis of 155 candidates from the second year of NASA’s K2 mission (Campaigns 5-8), yielding 60 statistically validated planets spanning a range of properties with median values of R p = 2.5 {R}\oplus , P = 7.1 days, T eq = 811 K, and J = 11.3 mag. The sample includes 24 planets in 11 mult…
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). III. A Large Sample of ALMA Sources in the GOODS-S
Bauer, F. E.; Wang, W. -H.; Barger, A. J. +3 more
We analyze the >4σ sources in the most sensitive 100 arcmin2 area (rms < 0.56 mJy) of a SCUBA-2 850 µm survey of the GOODS-S and present the 75 band-7 ALMA sources (>4.5σ) obtained from high-resolution interferometric follow-up observations. The raw SCUBA-2 >4σ limit is fainter than 2.25 mJy throughout this region, and…
Not all stars form in clusters - measuring the kinematics of OB associations with Gaia
Kruijssen, J. M. Diederik; Ward, Jacob L.
It is often stated that star clusters are the fundamental units of star formation and that most (if not all) stars form in dense stellar clusters. In this monolithic formation scenario, low-density OB associations are formed from the expansion of gravitationally bound clusters following gas expulsion due to stellar feedback. N-body simulations of …
Investigating the Response of Loop Plasma to Nanoflare Heating Using RADYN Simulations
Reale, Fabio; De Pontieu, B.; Carlsson, M. +5 more
We present the results of 1D hydrodynamic simulations of coronal loops that are subject to nanoflares, caused by either in situ thermal heating or nonthermal electron (NTE) beams. The synthesized intensity and Doppler shifts can be directly compared with Interface Region Imaging Spectrograph (IRIS) and Atmospheric Imaging Assembly (AIA) observatio…