Search Publications
Swift UVOT grism observations of nearby Type Ia supernovae - II. Probing the progenitor metallicity of SNe Ia with ultraviolet spectra
Filippenko, A. V.; Foley, R. J.; Kuin, N. P. M. +2 more
Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) are crucial for constraining the properties of their progenitor systems. Theoretical studies predicted that the UV spectra, which probe the outermost layers of an SN, should be sensitive to the metal content of the progenitor. Using the largest SN Ia UV (λ < 2900 Å) spectroscopic samp…
When do solar erupting hot magnetic flux ropes form?
Cheng, X.; Zhang, J.; Patsourakos, S. +2 more
Aims: We investigate the formation times of eruptive magnetic flux ropes relative to the onset of solar eruptions, which is important for constraining models of coronal mass ejection (CME) initiation.
Methods: We inspected uninterrupted sequences of 131 Å images that spanned more than eight hours and were obtained by the Atmospheric Imag…
Maximum entropy estimation of the Galactic bulge morphology via the VVV Red Clump
Coleman, B.; Paterson, D.; Gordon, C. +2 more
The abundance and narrow magnitude dispersion of Red Clump (RC) stars make them a popular candidate for mapping the morphology of the bulge region of the Milky Way. Using an estimate of the RC's intrinsic luminosity function, we extracted the three-dimensional density distribution of the RC from deep photometric catalogues of the VISTA Variables i…
Interstellar oxygen along the line of sight of Cygnus X-2
Waters, L. B. F. M.; Mutschke, H.; Costantini, E. +7 more
Interstellar dust permeates our Galaxy and plays an important role in many physical processes in the diffuse and dense regions of the interstellar medium (ISM). High-resolution X-ray spectroscopy, coupled with modelling based on laboratory dust measurements, provides a unique probe for investigating the interstellar dust properties along our line …
Modeling the Precession of the Warped Inner Accretion Disk in the Pulsars LMC X-4 and SMC X-1 with NuSTAR and XMM-Newton
Pottschmidt, Katja; Wilms, Jörn; Hickox, Ryan C. +3 more
We present a broadband X-ray study of the effect of superorbital periods on X-ray spectra and pulse profiles in the neutron star X-ray binaries LMC X-4 and SMC X-1. These two sources display periodic or quasiperiodic variations in luminosity of the order of tens of days, which are known to be superorbital, and are attributed to warped, precessing …
It Takes Two Planets in Resonance to Tango around K2-146
Cochran, William D.; Endl, Michael; Mahadevan, Suvrath +51 more
K2-146 is a cool, 0.358 ${M}_{\odot }$ dwarf that was found to host a mini-Neptune with a 2.67 day period. The planet exhibited strong transit timing variations (TTVs) of greater than 30 minutes, indicative of the presence of an additional object in the system. Here we report the discovery of the previously undetected outer planet in the system, K…
From peculiar morphologies to Hubble-type spirals: the relation between galaxy dynamics and morphology in star-forming galaxies at z ∼ 1.5
Smail, Ian; Swinbank, A. M.; Fisher, D. B. +14 more
We present an analysis of the gas dynamics of star-forming galaxies at z ∼ 1.5 using data from the KMOS Galaxy Evolution Survey. We quantify the morphology of the galaxies using HSTCANDELS imaging parametrically and non-parametrically. We combine the H α dynamics from KMOS with the high-resolution imaging to derive the relation between stellar mas…
The Strikingly Metal-rich Halo of the Sombrero Galaxy
Cohen, Roger E.; Chandar, Rupali; Goudfrooij, Paul +5 more
The nature of the Sombrero galaxy (M104 = NGC 4594) has remained elusive despite many observational studies at a variety of wavelengths. Here we present Hubble Space Telescope imaging of two fields at ∼16 and 33 kpc along the minor axis to examine stellar metallicity gradients in the extended spheroid. We use this imaging, extending more than 2 ma…
The CARMENES search for exoplanets around M dwarfs. A super-Earth planet orbiting HD 79211 (GJ 338 B)
Schmitt, J. H. M. M.; Amado, P. J.; Bauer, F. F. +27 more
Aims: We report on radial velocity time series for two M0.0 V stars, GJ 338 B and GJ 338 A, using the CARMENES spectrograph, complemented by ground-telescope photometry from Las Cumbres and Sierra Nevada observatories. We aim to explore the presence of small planets in tight orbits using the spectroscopic radial velocity technique.
Metho…
The Carnegie Supernova Project II. Observations of the luminous red nova AT 2014ej
Suntzeff, N. B.; Galbany, L.; Inserra, C. +29 more
We present optical and near-infrared broadband photometry and optical spectra of AT 2014ej from the Carnegie Supernova Project-II. These observations are complemented with data from the CHilean Automatic Supernova sEarch, the Public ESO Spectroscopic Survey of Transient Objects, and from the Backyard Observatory Supernova Search. Observational sig…