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Broadband X-Ray Constraints on the Accreting Black Hole in Quasar 4C 74.26
Yukita, M.; Ptak, A.; LaMassa, S. +2 more
X-ray data for quasar 4C 74.26 have previously been modeled with a broad Fe Kα emission line and reflection continuum originating in the inner part of the accretion disk around the central supermassive black hole (SMBH), i.e., the strong-gravity regime. We modeled broadband X-ray spectra from Suzaku and NuSTAR with MYTORUS, self-consistently accou…
Multiwavelength campaign on Mrk 509. XVI. Continued HST/COS monitoring of the far-ultraviolet spectrum
Kaastra, J. S.; Kriss, G. A.; Arav, N. +10 more
Aims: To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509, we used coordinated UV and X-ray spectral observations in 2012 to follow up our lengthier campaign conducted in 2009.
Methods: We observed Mrk 509 with the Cosmic Origins …
Magnetized Dust Clouds Penetrating the Terrestrial Bow Shock Detected by Multiple Spacecraft
Lai, H. R.; Russell, C. T.; Jia, Y. D. +1 more
Clouds of charged nanometer dust, produced in intra-meteoroid collisions and accelerated by the magnetized solar wind, twist the interplanetary magnetic field as they are accelerated. Depending on the cloud size, minutes to hours-long perturbations are observed by interplanetary spacecraft and have been termed interplanetary field enhancements (IF…
Results of Many-year Photometry of the Herbig Ae Star AB Aur in the Near Infrared
Grinin, V. P.; Shenavrin, V. I.; Baluev, R. V. +1 more
The results of many-year infrared observations of the Herbig AeBe star AB Aur at 1-5 µm (JHKLM bands) are presented. The duration of the photometric series, together with observations published earlier, is about 18 years. The observations demonstrate that, in contrast to the optical, the star is quite active in the studied infrared range. Th…
A method to calculate gravitational accelerations within discrete localized regions in the Milky Way
Kipper, Rain; Tenjes, Peeter; Tempel, Elmo
We present a method to calculate gravitational potential gradients within regions containing few 10s of thousands stars with known phase space coordinates. The central idea of the method is to calculate orbital arcs for each star within a given region for a certain parametrized potential (gravitational acceleration) and to assume that position of …
The footprint of cometary dust analogues - II. Morphology as a tracer of tensile strength and application to dust collection by the Rosetta spacecraft
Blum, J.; Gundlach, B.; Dominik, C. +6 more
The structure of cometary dust is a tracer of growth processes in the formation of planetesimals. Instrumentation on board the Rosetta mission to comet 67P/Churyumov-Gerasimenko captured dust particles and analysed them in situ. However, these deposits are a product of a collision within the instrument. We conducted laboratory experiments with com…
Clumpy dust rings around non-accreting young stars
Relles, Howard; Scholz, Aleks; Eislöffel, Jochen +3 more
We investigate four young, but non-accreting, very low mass stars in Orion, which show irregular eclipses by circumstellar dust. The eclipses are not recurring periodically, are variable in depth, lack a flat bottom, and their duration is comparable to the typical time-scale between eclipses. The dimming is associated with reddening consistent wit…
The complex phenomena of young stellar objects revealed by their X‑ray variability
Reale, F.; Sciortino, S.; Pillitteri, I. +1 more
X‑ray observations of young stellar objects (YSOs) have shown several complex phenomena at work. In recent years, a few X‑ray programs based on long, continuous, and, sporadically, simultaneous coordinated multiwavelength observations have paved the way to our current understanding of the physical processes at work, which very likely regulates the…
The 2016 UK Space Agency Mars Utah Rover Field Investigation (MURFI)
Coates, A. J.; Butcher, F. E. G.; Fawdon, P. +50 more
The 2016 Mars Utah Rover Field Investigation (MURFI) was a Mars rover field trial run by the UK Space Agency in association with the Canadian Space Agency's 2015/2016 Mars Sample Return Analogue Deployment mission. MURFI had over 50 participants from 15 different institutions around the UK and abroad. The objectives of MURFI were to develop experi…
IRAS 09002-4732: A Laboratory for the Formation of Rich Stellar Clusters
Garmire, Gordon P.; Feigelson, Eric D.; Broos, Patrick S. +2 more
IRAS 09002-4732 is a poorly studied embedded cluster of stars in the Vela Molecular Ridge at a distance of 1.7 kpc. Deep observations with the Chandra X-ray Observatory, combined with existing optical and infrared surveys, produce a catalog of 441 probable pre-main-sequence members of the region. The stellar spatial distribution has two components…