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Characterization of the precision premium in astrometry
Lin, F. R.; Peng, Q. Y.; Zheng, Z. J. +1 more
The precision premium, a concept in astrometry that was first presented by Pascu in 1994, initially means that the relative positional measurement of the Galilean satellites of Jupiter will be more accurate when their separations are small. Correspondingly, many observations have been obtained of these Galilean satellites since it was introduced. …
Bow shocks, bow waves, and dust waves - III. Diagnostics
Henney, William J.; Arthur, S. J.
Stellar bow shocks, bow waves, and dust waves all result from the action of a star's wind and radiation pressure on a stream of dusty plasma that flows past it. The dust in these bows emits prominently at mid-infrared wavelengths in the range 8 to 60 µm. We propose a novel diagnostic method, the τ-η diagram, for analysing these bows, which i…
Using Gaia DR2 to detect extratidal structures around the Galactic globular cluster NGC 362
Carballo-Bello, Julio A.
We explore the possibility of searching for extratidal features around the Galactic globular cluster NGC 362 using the Gaia DR2 (second data release) together with a modified version of a classical statistical decontamination algorithm. Our results suggest that an important stellar component is associated with this globular cluster, which is perfe…
Progenitors and explosion properties of supernova remnants hosting central compact objects: I. RCW 103 associated with the peculiar source 1E 161348-5055
Fryer, C. L.; Safi-Harb, S.; Braun, C.
We present a Chandra and XMM-Newton imaging and spectroscopic study of the supernova remnant (SNR) RCW 103 (G332.4-00.4) containing the central compact object 1E 161348-5055. The high-resolution Chandra X-ray images reveal enhanced emission in the south-eastern and north-western regions. Equivalent width line images of Fe L, Mg, Si, and S using XM…
Study of the X-ray properties of the neutron star binary 4U 1728-34 from the soft-to-hard state
Motta, S. E.; Belloni, T. M.; Méndez, Mariano +7 more
We studied five XMM-Newton observations of the neutron star binary 4U 1728-34 covering the hard, intermediate and soft spectral states. By jointly fitting the spectra with several reflection models, we obtained an inclination angle of 25°-53° and an iron abundance up to 10 times the solar. From the fits with reflection models, we found that the fl…
A massive cluster at z = 0.288 caught in the process of formation: The case of Abell 959
Brunetti, G.; Shimwell, T. W.; Cassano, R. +9 more
The largest galaxy clusters are observed still to be forming through major cluster-cluster mergers, often showing observational signatures such as radio relics and giant radio haloes. Using LOFAR Two-meter Sky Survey data, we present new detections of both a radio halo (with a spectral index of α _{143}^{1400}=1.48^{+0.06}_{-0.23}) and a likely ra…
A compact jet at the infrared heart of the prototypical low-luminosity AGN in NGC 1052
Tristram, K. R. W.; Prieto, M. A.; Asmus, D. +4 more
The feeble radiative efficiency characteristic of Low-Luminosity Active Galactic Nuclei (LLAGNs) is ascribed to a sub-Eddington accretion rate, typically at log (Lbol/Ledd) ≲ -3. At the finest angular resolutions that are attainable nowadays using mid-infrared (mid-IR) interferometry, the prototypical LLAGN in NGC 1052 remain…
Hyperluminous starburst gives up its secrets
Ivison, R. J.; Page, M. J.; Mainieri, V. +4 more
HATLAS J084933.4 + 021443 was identified as a dusty starburst via its rest-frame far-infrared (far-IR) emission. Multifrequency imaging and spectroscopy revealed a cluster of four dusty galaxies at z = 2.41, covering 80 kpc. Here, we use Atacama Large Millimetre Array to confirm a more distant, fifth protocluster member, and present X-ray and rest…
Rediscovering the tidal tails of NGC 288 with Gaia DR2
Carlberg, Raymond; Hunt, Jason A. S.; Webb, Jeremy J. +2 more
NGC 288 is a Galactic globular cluster having observed extra-tidal structure, without confirmed tidal tails. Gaia DR2 provides photometric and astrometric data for many of the stars in NGC 288 and its extra-tidal structure. To compare with the Gaia data, we simulate a N-body model of a star cluster with the same orbit as NGC 288 in a Milky Way pot…
Deep ALMA search for CO gas in the HD 95086 debris disc
MacGregor, Meredith A.; Hughes, A. Meredith; Wilner, David J. +7 more
One of the defining properties of debris discs compared to protoplanetary discs used to be their lack of gas, yet small amounts of gas have been found around an increasing number of debris discs in recent years. These debris discs found to have gas tend to be both young and bright. In this paper, we conduct a deep search for CO gas in the system H…