Search Publications
Data-driven Derivation of Stellar Properties from Photometric Time Series Data Using Convolutional Neural Networks
Angus, Ruth; Huber, Daniel; Ness, Melissa K. +2 more
Stellar variability is driven by a multitude of internal physical processes that depend on fundamental stellar properties. These properties are our bridge to reconciling stellar observations with stellar physics and to understand the distribution of stellar populations within the context of galaxy formation. Numerous ongoing and upcoming missions …
Investigating the Accretion Nature of Binary Supermassive Black Hole Candidate SDSS J025214.67-002813.7
Shi, Fangzheng; Gültekin, Kayhan; Chen, Yu-Ching +3 more
We present results of a multiwavelength analysis of SDSS J025214.67-002813.7, a system that has been previously classified as a binary active galactic nucleus (AGN) candidate based on periodic signals detected in the optical light curves. We use available radio-X-ray observations of the system to investigate the true accretion nature. Analyzing ne…
Three-dimensional Magnetic and Thermodynamic Structures of Solar Microflares
Cheng, X.; Ding, M. D.; Chen, J. +2 more
Microflares, one of the small-scale solar activities, are believed to be caused by magnetic reconnection. Nevertheless, their three-dimensional (3D) magnetic structures, thermodynamic structures, and physical links to reconnection are unclear. In this Letter, based on a high-resolution 3D radiative magnetohydrodynamic simulation of the quiet Sun s…
A Morphometric Investigation of Large-Scale Crustal Shortening on Mars
Byrne, P. K.; Atkins, R. M.; Bohnenstiehl, D. R. +1 more
Mars' surface exhibits abundant topographic expressions of large thrust fault-related folds that have been attributed to global planetary contraction. Morphometric analyses of such structures provide insight into their growth history. With global THEMIS imagery and HRSC-MOLA topographic data, 49 thrusts with lengths between 35 and 544 km were mapp…
Magnetic gradiometry using frequency-domain filtering
Russell, Christopher T.; Raymond, Carol A.; Polanskey, Carol A. +7 more
Accurate measurements of ambient planetary and interplanetary magnetic fields using spacecraft magnetometers typically require accounting for interfering magnetic fields generated by the flight system (FS). The most common method for removing FS-generated time-variable magnetic fields is narrow-band and low-pass filtering of magnetic field data in…
SDSS-IV MaStar: Stellar parameter determination with continuum-supplemented full-spectrum fitting
Bizyaev, Dmitry; Beers, Timothy C.; Holtzman, Jon A. +13 more
Aims: We present a stellar parameter catalog built to accompany the MaStar Stellar Library, which is a comprehensive collection of empirical, medium-resolution stellar spectra.
Methods: We constructed this parameter catalog by using a multicomponent χ2 fitting approach to match MaStar spectra to models generated by interpolati…
Dawn-Dusk Ion Flow Asymmetry in the Plasma Sheet: Interplanetary Magnetic Field By Versus Distance With Respect to the Neutral Sheet
Hamrin, M.; Pitkänen, T.; Chong, Ghai Siung +1 more
Previous studies have shown that the average dawn-dusk component of the perpendicular plasma flow in the plasma sheet (V⊥) can vary depending on the distance relative to the neutral sheet and the dawn-dusk component of the interplanetary magnetic field (IMF By). In this study, we combined 33 years of data from the Geotail, Ti…
Signature of a chemical spread in the open cluster M37
Salaris, M.; Bedin, L. R.; Pietrinferni, A. +2 more
Recent Gaia photometry of the open cluster M37 has disclosed the existence of an extended main sequence turn-off - like in Magellanic clusters younger than about 2 Gyr - and a main sequence that is broadened in colour beyond what is expected from the photometric errors, at magnitudes well below the region of the extended turn-off, where neither ag…
Analysis of the public HARPS/ESO spectroscopic archive. Jupiter-like planets around HD103891 and HD105779
Mazeh, T.; Zucker, S.; Tal-Or, L. +3 more
Aims: We use the recently published database of radial velocities (RVs) that were derived from fifteen years of HARPS/ESO observations to search for planet candidates.
Methods: For targets with sufficient RV data, we applied an automated algorithm to identify significant periodic signals and fit a Keplerian model for orbital estimates. W…
Ice Features of Low-luminosity Protostars in Near-infrared Spectra of AKARI/IRC
Choi, Minho; Lee, Jeong-Eun; Dunham, Michael M. +8 more
We present near-infrared spectra of three low-luminosity protostars and one background star in the Perseus molecular cloud, acquired using the infrared camera on board the AKARI space telescope. For the comparison with different star-forming environments, we also present spectra of the massive protostar AFGL 7009S, where the protostellar envelope …