Search Publications
Missions
Journals
Publication Years
A stellar relic filament in the Orion star-forming region
Anderson, Richard I.; Boffin, Henri M. J.; Jerabkova, Tereza +1 more
We report the discovery of the oldest stellar substructure in the Orion star-forming region (OSFR), the Orion relic filament. The relic filament is physically associated with the OSFR, as demonstrated by Gaia DR2 photometry and astrometry, as well as by targeted radial velocity follow-up observations of a bright subsample of proper motion-selected…
First ALMA Millimeter-wavelength Maps of Jupiter, with a Multiwavelength Study of Convection
de Pater, Imke; Sault, R. J.; Wong, Michael H. +15 more
We obtained the first maps of Jupiter at 1-3 mm wavelength with the Atacama Large Millimeter/Submillimeter Array (ALMA) on 2017 January 3-5, just days after an energetic eruption at 16.°5S jovigraphic latitude had been reported by the amateur community, and about two to three months after the detection of similarly energetic eruptions in the north…
Detection of a 50° long Trailing Tidal Tail for the Globular Cluster M5
Grillmair, Carl J.
Using photometry and proper motions from Gaia Data Release 2, we detect a 50° long stream of about 70 stars extending westward from the halo globular cluster M5. Based on the similarities in distance, proper motions, inferred color-magnitude distribution, and trajectory, we identify this stream as the trailing tidal tail of M5. While the surface d…
HST unveils a compact mildly relativistic broad-line region in the candidate true type 2 NGC 3147
Laor, Ari; Bianchi, Stefano; La Franca, Fabio +9 more
NGC 3147 has been considered the best case of a true type 2 AGN: an unobscured AGN, based on the unabsorbed compact X-ray continuum, which lacks a broad-line region (BLR). However, the very low luminosity of NGC 3147 implies a compact BLR, which produces very broad lines, hard to detect against the dominant background host galaxy. Narrow (0.1 arcs…
Episodically Active Asteroid 6478 Gault
Kotulla, Ralf; Jewitt, David; Rajagopal, Jayadev +4 more
We present imaging and spectroscopic observations of 6478 Gault, a ∼6 km diameter inner main-belt asteroid currently exhibiting strong, comet-like characteristics. Three distinct tails indicate that ultra-slow dust (ejection speed 0.15 ± 0.05 m s-1) was emitted from Gault in separate episodes beginning UT 2018 October 28 ± 5 (Tail A), U…
A Tail Structure Associated with a Protoplanetary Disk around SU Aurigae
Dong, Ruobing; Liu, Sheng-Yuan; Tamura, Motohide +4 more
We present Atacama Large Millimeter/submillimeter Array observations of the CO (J = 2 - 1) line emission from a protoplanetary disk around T-Tauri star SU Aurigae (hereafter SU Aur). Previous observations in optical and near-infrared wavelengths find a unique structure in SU Aur. One of the highlights of the observational results is that an extend…
Olivine-dominated A-type asteroids in the main belt: Distribution, abundance and relation to families
Hsieh, Henry H.; Moskovitz, Nicholas A.; Polishook, David +5 more
Differentiated asteroids are rare in the main asteroid belt despite evidence for ∼ 100 distinct differentiated bodies in the meteorite record. We have sought to understand why so few main-belt asteroids differentiated and where those differentiated bodies or fragments reside. Using the Sloan Digital Sky Survey (SDSS) to search for a needle in a ha…
Relation between winds and jets in radio-loud AGN
Mehdipour, Missagh; Costantini, Elisa
We have investigated the relation between the two modes of outflow (wind and jet) in radio-loud active galactic nuclei (AGN). For this study we have carried out a systematic and homogeneous analysis of XMM-Newton spectra of a sample of 16 suitable radio-loud Seyfert-1 AGN. The ionised winds in these AGN are parameterised through high-resolution X-…
Discovery of a New Stellar Subpopulation Residing in the (Inner) Stellar Halo of the Milky Way
Beers, Timothy C.; Placco, Vinicius M.; Robin, Annie C. +8 more
We report the discovery of a unique collection of metal-poor giant stars that exhibit anomalously high levels of 28Si, clearly above typical Galactic levels. Our sample spans a narrow range of metallicities, peaking at -1.07 ± 0.06, and exhibits abundance ratios of [Si, Al/Fe] that are as extreme as those observed in Galactic globular c…
Gaia stellar kinematics in the head of the Orion A cloud: runaway stellar groups and gravitational infall
Garmire, G. P.; Getman, K. V.; Kuhn, M. A. +1 more
This work extends previous kinematic studies of young stars in the head of the Orion A cloud (OMC-1/2/3/4/5). It is based on large samples of infrared, optical, and X-ray selected pre-main-sequence stars with reliable radial velocities and Gaia-derived parallaxes and proper motions. Stellar kinematic groups are identified assuming they mimic the m…