Search Publications
The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180
Ebrero, J.; Schartel, N.; Santos-Lleó, M. +15 more
We present joint XMM-Newton and NuSTAR observations of the 'bare' narrow-line Seyfert 1 Ton S180 (z = 0.062), carried out in 2016 and providing the first hard X-ray view of this luminous galaxy. We find that the 0.4-30 keV band cannot be self-consistently reproduced by relativistic reflection models, which fail to account simultaneously for the so…
A DECam view of the diffuse dwarf galaxy Crater II - Variable stars
Nidever, David L.; Olsen, Knut; Walker, Alistair R. +11 more
Time series observations of a single dithered field centred on the diffuse dwarf satellite galaxy Crater II were obtained with the Dark Energy Camera (DECam) at the 4m Blanco Telescope at Cerro Tololo Inter-American Observatory, Chile, uniformly covering up to two half-light radii. Analysis of the g and I time series results in the identification …
Infalling gas in a Lyman-α blob
Kohno, Kotaro; Lehnert, Matthew D.; Menten, Karl M. +11 more
Lyman-α blobs (LABs) are spatially extended nebulae of emission in the Lyman-α (Lyα) line of hydrogen, seen at high redshifts1,2, and most commonly found in the dense environment of star-forming galaxies3,4. A recent study showed that nearly 100% of the sky is covered by Lyα emission around high-redshift galaxies5-7
Orbital and spectral characterization of the benchmark T-type brown dwarf HD 19467B
Henning, T.; Brandner, W.; Ségransan, D. +42 more
Context. Detecting and characterizing substellar companions for which the luminosity, mass, and age can be determined independently is of utter importance to test and calibrate the evolutionary models due to uncertainties in their formation mechanisms. HD 19467 is a bright and nearby star hosting a cool brown dwarf companion detected with radial v…
Physical Characterization of Interstellar Comet 2I/2019 Q4 (Borisov)
Tholen, David J.; Ye, Quan-Zhi; Hui, Man-To +2 more
We present a study of interstellar comet 2I/2019 Q4 (Borisov) using both preperihelion and postperihelion observations spanning late September 2019 through late January 2020. The intrinsic brightness of the comet was observed to continuously decline throughout the timespan, likely due to the decreasing effective scattering cross-section as a resul…
Charge induced acceleration noise in the LISA gravitational reference sensor
Sumner, Timothy J.; Wass, Peter J.; Conklin, John W. +2 more
The presence of free charge on isolated proof-masses, such as those within space-borne gravitational reference sensors, causes a number of spurious forces which will give rise to associated acceleration noise. A complete discusssion of each charge induced force and its linear acceleration noise is presented. The resulting charge acceleration noise…
Photometric, kinematic, and variability study in the young open cluster NGC 1960
Joshi, Y. C.; Maurya, J.; Panchal, A. +3 more
We present a comprehensive photometric analysis of a young open cluster NGC 1960 (= M36) along with the long-term variability study of this cluster. Based on the kinematic data of Gaia DR2, the membership probabilities of 3871 stars are ascertained in the cluster field among which 262 stars are found to be cluster members. Considering the kinemati…
Jurassic: A chemically anomalous structure in the Galactic halo
Beers, Timothy C.; Minniti, Dante; Fernández-Trincado, José G.
Detailed elemental-abundance patterns of giant stars in the Galactic halo measured by the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have revealed the existence of a unique and significant stellar subpopulation of silicon-enhanced ([Si/Fe] ≳ +0.5) metal-poor stars, spanning a wide range of metallicities (-1.5 ≲ [Fe/H] ≲ -0.8…
The role of Galactic H II regions in the formation of filaments. High-resolution submilimeter imaging of RCW 120 with ArTéMiS
Roussel, H.; André, Ph.; Arzoumanian, D. +13 more
Context. Massive stars and their associated ionized (H II) regions could play a key role in the formation and evolution of filaments that host star formation. However, the properties of filaments that interact with H II regions are still poorly known.
Aims: To investigate the impact of H II regions on the formation of filaments, we imaged the…
Using Data Imputation for Signal Separation in High-contrast Imaging
Debes, John H.; Duchêne, Gaspard; Perrin, Marshall D. +5 more
To characterize circumstellar systems in high-contrast imaging, the fundamental step is to construct a best point-spread function (PSF) template for the noncircumstellar signals (I.e., starlight and speckles) and separate it from the observation. With existing PSF construction methods, the circumstellar signals (e.g., planets, circumstellar disks)…