Search Publications
Forecasting the Impact of Stellar Activity on Transiting Exoplanet Spectra
Line, Michael R.; Zellem, Robert T.; Ciardi, David R. +8 more
Exoplanet host star activity, in the form of unocculted starspots or faculae, alters the observed transmission and emission spectra of the exoplanet. This effect can be exacerbated when combining data from different epochs if the stellar photosphere varies between observations due to activity. Here, we present a method to characterize and correct …
The two-component giant radio halo in the galaxy cluster Abell 2142
Brunetti, G.; Rossetti, M.; Shimwell, T. W. +9 more
Aims: We report on a spectral study at radio frequencies of the giant radio halo in A 2142 (z = 0.0909), which we performed to explore its nature and origin. The optical and X-ray properties of the cluster suggest that A 2142 is not a major merger and the presence of a giant radio halo is somewhat surprising.
Methods: We performed deep r…
Variable Dynamics in the Inner Disk of HD 135344B Revealed with Multi-epoch Scattered Light Imaging
Kraus, Stefan; Milli, Julien; Benisty, Myriam +12 more
We present multi-epoch Very Large Telescope/Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE) observations of the protoplanetary disk around HD 135344B (SAO 206462). The J-band scattered light imagery reveal, with high spatial resolution (∼41 mas, 6.4 au), the disk surface beyond ∼20 au. Temporal variations are identified in the a…
Suzaku observations of the merging galaxy cluster Abell 2255: The northeast radio relic
Zhang, Y. -Y.; Kaastra, J. S.; Fukazawa, Y. +12 more
We present the results of deep 140 ks Suzaku X-ray observations of the north-east (NE) radio relic of the merging galaxy cluster Abell 2255. The temperature structure of Abell 2255 is measured out to 0.9 times the virial radius (1.9 Mpc) in the NE direction for the first time. The Suzaku temperature map of the central region suggests a complex tem…
Intergalactic Lyman continuum photon budget in the past 5 billion years
Khaire, Vikram; Srianand, Raghunathan; Choudhury, Tirthankar Roy +1 more
We constrain the H I photoionization rate (Γ _{H I}) at z ≲ 0.45 by comparing the flux probability distribution function and power spectrum of the Lyα forest data along 82 Quasi-Stellar Object (QSO) sightlines obtained using Cosmic Origins Spectrograph with models generated from smoothed particle hydrodynamic simulations. We have developed a modul…
Swift observations of V404 Cyg during the 2015 outburst: X-ray outflows from super-Eddington accretion
Altamirano, D.; Sanna, A.; Knigge, C. +11 more
The black hole (BH) binary V404 Cyg entered the outburst phase in 2015 June after 26 yr of X-ray quiescence, and with its behaviour broke the outburst evolution pattern typical of most BH binaries. We observed the entire outburst with the Swift satellite and performed time-resolved spectroscopy of its most active phase, obtaining over a thousand s…
Predicting Flares and Solar Energetic Particle Events: The FORSPEF Tool
Papaioannou, A.; Anastasiadis, A.; Kouloumvakos, A. +4 more
A novel integrated prediction system for solar flares (SFs) and solar energetic particle (SEP) events is presented here. The tool called forecasting solar particle events and flares (FORSPEF) provides forecasts of solar eruptive events, such as SFs with a projection to occurrence and velocity of coronal mass ejections (CMEs), and the likelihood of…
The NuSTAR Serendipitous Survey: The 40-month Catalog and the Properties of the Distant High-energy X-Ray Source Population
Harrison, F. A.; Stern, D.; Zhang, W. W. +35 more
We present the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ≈20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg2, and 497 sources detecte…
Updated 34-band Photometry for the Sings/KINGFISH Samples of Nearby Galaxies
Helou, G.; Boquien, M.; Roussel, H. +22 more
We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel) and SINGS (Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions fr…
Interpreting the star formation efficiency of nearby molecular clouds with ionizing radiation
Hennebelle, Patrick; Soler, Juan D.; Geen, Sam
We investigate the origin of observed local star formation relations using radiative magnetohydrodynamic simulations with self-consistent star formation and ionizing radiation. We compare these clouds to the density distributions of local star-forming clouds and find that the most diffuse simulated clouds match the observed clouds relatively well.…