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Luminosities and infrared excess in Type II and anomalous Cepheids in the Large and Small Magellanic Clouds
Groenewegen, M. A. T.; Jurkovic, M. I.
Type II and anomalous Cepheids (ACs) are useful distance indicators when there are too few classical Cepheids or when RR Lyrae stars are too faint. Type II and ACs follow a period-luminosity relation as well, but they are less well-studied classes of objects. In this paper we study the sample of 335 Type II and ACs in the Small and Large Magellani…
A swirling jet in the quasar 1308+326
Britzen, S.; Krause, M.; Moser, L. +12 more
Context. Despite numerous and detailed studies of the jets of active galactic nuclei (AGN) on pc-scales, many questions are still debated. The physical nature of the jet components is one of the most prominent unsolved problems, as is the launching mechanism of jets in AGN. The quasar 1308+326 (z = 0.997) allows us to study the overall properties …
Noncircular features in Saturn's rings IV: Absolute radius scale and Saturn's pole direction
Nicholson, Philip D.; French, Richard G.; McGhee-French, Colleen A. +6 more
We present a comprehensive solution for the geometry of Saturn's ring system, based on orbital fits to an extensive set of occultation observations of 122 individual ring edges and gaps. We begin with a restricted set of very high quality Cassini VIMS, UVIS, and RSS measurements for quasi-circular features in the C and B rings and the Cassini Divi…
VLA Measurements of Faraday Rotation through Coronal Mass Ejections
Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J. +1 more
Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun, which play an important role in space weather. Faraday rotation is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. Faraday rotation is proportional to the path integral through th…
Sulphur-bearing molecules in AGB stars. I. The occurrence of hydrogen sulphide
Olofsson, H.; Decin, L.; De Beck, E. +4 more
Context. Sulphur is a relatively abundant element in the local Galaxy that is known to form a variety of molecules in the circumstellar envelopes of AGB stars. The abundances of these molecules vary based on the chemical types and mass-loss rates of AGB stars.
Aims: Through a survey of (sub-)millimetre emission lines of various sulphur-bearin…
The Dense Molecular Gas and Nuclear Activity in the ULIRG IRAS 13120-5453
Treister, E.; Armus, L.; van der Werf, P. +12 more
We present new Atacama Large Millimeter/submillimeter Array Band 7 (∼340 GHz) observations of the dense gas tracers HCN, HCO+, and CS in the local, single-nucleus, ultraluminous infrared galaxy IRAS 13120-5453. We find centrally enhanced HCN (4-3) emission, relative to HCO+ (4-3), but do not find evidence for radiative pumpin…
Hard X-Ray-selected AGNs in Low-mass Galaxies from the NuSTAR Serendipitous Survey
Harrison, F. A.; Stern, D.; Alexander, D. M. +14 more
We present a sample of 10 low-mass active galactic nuclei (AGNs) selected from the 40-month Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The sample is selected to have robust NuSTAR detections at 3{--}24 {keV}, to be at z< 0.3, and to have optical r-band magnitudes at least 0.5 mag fainter than an {L}\star ga…
The Plasma Parameters and Geometry of Cool and Warm Active Region Loops
Fu, Hui; Madjarska, Maria S.; Li, Bo +5 more
How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyze observations of 50 whole active region loops taken with the Extreme-ultraviolet Imaging Spectrometer on board the Hinode satellite. Eleven loops were classified as cool loops (<1 MK) and 39 as warm loops (1-2 MK). We…
Approaching hell's kitchen: Molecular daredevil clouds in the vicinity of Sagittarius A*
Eckart, Andreas; Moser, Lydia; García-Marin, Macarena +9 more
We report serendipitous detections of line emission with the Atacama Large Millimeter/submillimeter Array (ALMA) in bands 3, 6, and 7 in the central parsec down to within 1'' around Sgr A* at an up to now highest resolution (<0.5'') view of the Galactic center (GC) in the submillimeter (sub-mm) domain. From the 100 GHz continuum and the H39α em…
A stellar census of the nearby, young 32 Orionis group
Murphy, Simon J.; Mamajek, Eric E.; Bell, Cameron P. M.
The 32 Orionis group was discovered almost a decade ago and despite the fact that it represents the first northern, young (age ∼ 25 Myr) stellar aggregate within 100 pc of the Sun (d ≃ 93 pc), a comprehensive survey for members and detailed characterization of the group has yet to be performed. We present the first large-scale spectroscopic survey…