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An updated detailed characterization of planes of satellites in the MW and M31
Pawlowski, Marcel S.; Santos-Santos, Isabel M.; Domínguez-Tenreiro, Rosa
We present a detailed characterization of planes of satellite galaxies in the Milky Way (MW) and M31. For a positional analysis, we introduce an extension to the '4-galaxy-normal density plot' method from Pawlowski, Kroupa & Jerjen. It finds the normal directions to the predominant planar configurations of satellites of a system, yielding for …
The search for galaxy cluster members with deep learning of panchromatic HST imaging and extensive spectroscopy
Grillo, C.; Rosati, P.; Vanzella, E. +9 more
Context. The next generation of extensive and data-intensive surveys are bound to produce a vast amount of data, which can be efficiently dealt with using machine-learning and deep-learning methods to explore possible correlations within the multi-dimensional parameter space.
Aims: We explore the classification capabilities of convolution neu…
The chemical nature of the young 120-Myr-old nearby Pisces-Eridanus stellar stream flowing through the Galactic disc
Curtis, Jason; Hawkins, Keith; Lucey, Madeline
Recently, a new cylindrical-shaped stream of stars up to 700 pc long was discovered hiding in the Galactic disc using kinematic data enabled by the Gaia mission. This stream of stars, dubbed Pisces-Eridanus (Psc-Eri), was initially thought to be as old as 1 Gyr, yet its stars shared a rotation period distribution consistent with a population that …
Observability of dusty debris discs around M-stars
Lestrade, Jean-François; Booth, Mark; Krivov, Alexander V. +1 more
Debris discs are second-generation dusty discs formed by collisions of planetesimals. Many debris discs have been found and resolved around hot and solar-type stars. However, only a handful have been discovered around M-stars, and the reasons for their paucity remain unclear. Here, we check whether the sensitivity and wavelength coverage of presen…
Photometric Redshift Estimation with Galaxy Morphology Using Self-organizing Maps
Cooray, Asantha; Häußler, Boris; Nayyeri, Hooshang +1 more
We use multiband optical and near-infrared photometric observations of galaxies in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey to predict photometric redshifts using artificial neural networks. The multiband observations span from 0.39 to 8.0 µm for a sample of ∼1000 galaxies in the GOODS-S field for which robust size …
Stellar X-Ray Activity Across the Hertzsprung-Russell Diagram. I. Catalogs
Liu, Jifeng; Bai, Yu; Wang, Song +1 more
Stellar magnetic activity provides substantial information on the magnetic dynamo and the coronal heating process. We present a catalog of X-ray activity for about 6000 stars, based on the Chandra and Gaia DR2 data. We also classified more than 3000 stars as young stellar objects, dwarf stars, or giant stars. By using the stars with valid stellar …
Milky Way Subsystems from Globular Cluster Kinematics Using Gaia DR2 and HST Data
Bobylev, V. V.; Bajkova, A. T.; Carraro, G. +2 more
We employ Gaia DR2 proper motions for 151 Milky Way globular clusters (GCs) from Vasiliev in tandem with distances and line-of-sight velocities to derive their kinematical properties. To assign clusters to the Milky Way thick disk, bulge, and halo, we follow the approach of Posti et al., who distinguished among different Galactic stellar component…
Investigating the magnetospheric accretion process in the young pre-transitional disk system DoAr 44 (V2062 Oph). A multiwavelength interferometric, spectropolarimetric, and photometric observing campaign
Moutou, C.; Bayo, A.; Donati, J. -F. +13 more
Context. Young stars interact with their accretion disk through their strong magnetosphere.
Aims: We aim to investigate the magnetospheric accretion/ejection process in the young stellar system DoAr 44 (V2062 Oph).
Methods: We monitored the system over several rotational cycles, combining high-resolution spectropolarimetry at both optica…
Modelling X-ray RMS spectra I: intrinsically variable AGNs
Fabian, A. C.; Alston, W. N.; Parker, M. L. +1 more
We present simple XSPEC models for fitting excess variance spectra of active galactic nuclei. Using a simple Monte Carlo approach, we simulate a range of spectra corresponding to physical parameters varying, then calculate the resulting variance spectra. Starting from a variable power law, we build up a set of models corresponding to the different…
Implications of the Gaia sausage for dark matter nuclear interactions
Buch, Jatan; Leung, John Shing Chau; Fan, JiJi
The advent of the Gaia era has led to potentially revolutionary understanding of dark matter (DM) dynamics in our galaxy, which has important consequences for direct detection (DD) experiments. In this paper, we study how the empirical DM velocity distribution inferred from Gaia-sausage, a dominant substructure in the solar neighborhood, affects t…