Search Publications
Starburst to Quiescent from HST/ALMA: Stars and Dust Unveil Minor Mergers in Submillimeter Galaxies at z ∼ 4.5
Magnelli, B.; Smolčić, V.; van Kampen, E. +32 more
Dust-enshrouded, starbursting, submillimeter galaxies (SMGs) at z ≥ 3 have been proposed as progenitors of z ≥ 2 compact quiescent galaxies (cQGs). To test this connection, we present a detailed spatially resolved study of the stars, dust, and stellar mass in a sample of six submillimeter-bright starburst galaxies at z ∼ 4.5. The stellar UV emissi…
Extreme Kinematics of the 2017 September 10 Solar Eruption and the Spectral Characteristics of the Associated Energetic Particles
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
We report on the 2017 September 10 ground-level enhancement (GLE) event associated with a coronal mass ejection whose initial acceleration (∼9.1 km s-2) and initial speed (∼4300 km s-1) were among the highest observed in the Solar and Heliospheric Observatory era. The GLE event was of low intensity (∼4.4% above background) an…
Three-dimensional Circulation Driving Chemical Disequilibrium in WASP-43b
Mendonça, João M.; Heng, Kevin; Tsai, Shang-min +2 more
Spectral features in the observed spectra of exoplanets depend on the composition of their atmospheres. A good knowledge of the main atmospheric processes that drive the chemical distribution is therefore essential to interpret exoplanetary spectra. An atmosphere reaches chemical equilibrium if the rates of the forward and backward chemical reacti…
A Potential Cyclotron Resonant Scattering Feature in the Ultraluminous X-Ray Source Pulsar NGC 300 ULX1 Seen by NuSTAR and XMM-Newton
Harrison, F. A.; Fabian, A. C.; Pinto, C. +14 more
Based on phase-resolved broadband spectroscopy using XMM-Newton and NuSTAR, we report on a potential cyclotron resonant scattering feature (CRSF) at E ∼ 13 keV in the pulsed spectrum of the recently discovered ultraluminous X-ray source (ULX) pulsar NGC 300 ULX1. If this interpretation is correct, the implied magnetic field of the central neutron …
Compton-thick AGNs in the NuSTAR Era
Vignali, C.; Comastri, A.; Ajello, M. +3 more
We present the 2-100 keV spectral analysis of 30 candidate Compton-thick-(CT-)active galactic nuclei (AGNs) selected in the Swift-Burst Alert Telescope (BAT) 100 month survey. The average redshift of these objects is < z> ∼ 0.03, and they all lie within ∼500 Mpc. We used the MyTorus model to perform X-ray spectral fittings both without and w…
MIKiS: The Multi-instrument Kinematic Survey of Galactic Globular Clusters. I. Velocity Dispersion Profiles and Rotation Signals of 11 Globular Clusters
Dalessandro, E.; Valenti, E.; Bellazzini, M. +10 more
We present the first results of the Multi-Instrument Kinematic Survey of Galactic Globular Clusters (GGCs), a project aimed at exploring the internal kinematics of a representative sample of GGCs from the radial velocity of individual stars, covering the entire radial extension of each system. This is achieved by exploiting the formidable combinat…
Microphysics of KCl and ZnS Clouds on GJ 1214 b
Benneke, Björn; Gao, Peter
Clouds in the atmospheres of exoplanets confound characterization efforts by reducing, eliminating, and distorting the spectral signatures of molecular abundances. As such, interpretations of exoplanet spectra strongly depend on the choice of cloud model, many of which are highly simplified and lack predictive power. In this work, we use a cloud m…
Spatially Resolved Stellar Kinematics from LEGA-C: Increased Rotational Support in z ∼ 0.8 Quiescent Galaxies
Bell, Eric F.; Maseda, Michael V.; Franx, Marijn +18 more
We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at z = 0.6-1 from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20 kpc, or to an average of 2.7Re. Combined with central stellar velocity dispersions (σ0) this provi…
Resolving Quiescent Galaxies at z ≳ 2. II. Direct Measures of Rotational Support
Ellis, Richard S.; Belli, Sirio; Newman, Andrew B. +1 more
Stellar kinematics provide insights into the masses and formation histories of galaxies. At high redshifts, spatially resolving the stellar kinematics of quiescent galaxies is challenging due to their compact sizes. Using deep near-infrared spectroscopy, we have measured the resolved stellar kinematics of four quiescent galaxies at z = 1.95-2.64, …
A Gap in the Lower Main Sequence Revealed by Gaia Data Release 2
Gies, Douglas R.; Henry, Todd J.; Jao, Wei-Chun +1 more
We present the discovery of a gap near M G ≈ 10 in the main sequence on the Hertzsprung-Russell Diagram (HRD) based on measurements presented in Gaia Data Release 2 (DR2). Using an observational form of the HRD with M G representing luminosity and G BP - G RP representing temperature, the gap present…