Search Publications
A celestial matryoshka: dynamical and spectroscopic analysis of the Albireo system
Drimmel, Ronald; Bastian, Ulrich; Sozzetti, Alessandro +4 more
We present a spectroscopic characterization and a new orbital solution for the binary system β Cyg Aa/Ac (MCA 55), the primary component ( β Cyg A) of the well-known wide double star Albireo. By matching evolutionary tracks to the physical parameters of all three Albireo stars ( β Cyg Aa, Ac, and B) as obtained from a spectroscopic analysis of TIG…
Dynamics of the spiral-arm corotation and its observable footprints in the Solar Neighborhood
Pérez-Villegas, Angeles; Barros, Douglas A.; Michtchenko, Tatiana A. +1 more
This article discusses the effects of the spiral-arm corotation on the stellar dynamics in the Solar Neighborhood (SN). All our results presented here rely on: 1) observational evidence that the Sun lies near the corotation circle, where stars rotate with the same angular velocity as the spiral-arm pattern; the corotation circle establishes domain…
MUSE narrow field mode observations of the central kinematics of M15
Dalessandro, Emanuele; Kamann, Sebastian; Sollima, Antonio +4 more
We present observations of the stellar kinematics of the centre of the core collapsed globular cluster M15 obtained with the MUSE integral field spectrograph on the Very Large Telescope operating in narrow field mode. Thanks to the use of adaptive optics, we obtain a spatial resolution of 0.1 arcsec and are able to reliably measure the radial velo…
Searching for Dwarf Galaxies in Gaia DR2 Phase-space Data Using Wavelet Transforms
Darragh-Ford, Elise; Wechsler, Risa H.; Nadler, Ethan O. +1 more
We present a wavelet-based algorithm to identify dwarf galaxies in the Milky Way in Gaia DR2 data. Our algorithm detects overdensities in 4D position-proper-motion space, making it the first search to explicitly use velocity information to search for dwarf galaxy candidates. We optimize our algorithm and quantify its performance by searching for m…
Pairs of giant shock waves (N-waves) in merging galaxy clusters
Churazov, Eugene; Zhuravleva, Irina; Zhang, Congyao
When a subcluster merges with a larger galaxy cluster, a bow shock is driven ahead of the subcluster. At a later merger stage, this bow shock separates from the subcluster, becoming a 'runaway' shock that propagates down the steep density gradient through the cluster outskirts and approximately maintains its strength and the Mach number. Such shoc…
Census of High- and Medium-mass Protostars. V. CO Abundance and the Galactic XCO Factor
Pitts, Rebecca L.; Barnes, Peter J.
We present the second dust continuum data release in the Census of High- and Medium-mass Protostars (CHaMP), expanding the methodology trialed in Pitts et al. to the entire CHaMP survey area (280° < ℓ < 300°, - 4° < b < + 2°). This release includes maps of dust temperature (Td), H2 column density ( ${N}_{{{\rm{H}}…
Shock Properties and Associated Characteristics of Solar Energetic Particles in the 2017 September 10 Ground-level Enhancement Event
Jin, Meng; Liu, Ying D.; Xu, Xiaojun +3 more
The solar eruption on 2017 September 10 was accompanied by a fast coronal mass ejection (~3000 km s-1) and produced a ground-level enhancement (GLE) event at Earth. Multiple-viewpoint remote sensing observations are used to find the three-dimensional (3D) structure of the shock. We determine the shock parameters by combining the 3D shoc…
Local Active Galactic Nuclei with Large Broad-Hα Variability Reside in Red Galaxies
Wang, Jing; Liu, Wen-Juan; Yao, Su +4 more
Inspired by our serendipitous discovery of six active galactic nuclei (AGNs) with varying broad-Hα fluxes over years from our search for intermediate-mass black holes (IMBHs), we conduct a systematic investigation of changing-look (CL) and large-variability AGNs. We collect all the CL AGNs at z < 0.15 and the reverberation-mapped AGNs with stro…
Pebbles in an embedded protostellar disk: the case of CB 26
Henning, Thomas; Zhang, Chuan-Peng; Launhardt, Ralf +2 more
Context. Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins.
Aims: We study the physical structure and grain growth in the edge-on disk that surrounds the ≈1 Myr old low-mass (≈0.55 M⊙) protostar embedded in the Bok globule CB26 t…
Shock Mach Number Estimates Using Incomplete Measurements
Russell, Christopher T.; Dimmock, Andrew P.; Gedalin, Michael
The Mach number is one of the most important parameters of collisionless shocks. The accuracy of its observational determination is compromised by several complications. Incomplete measurements of plasma parameters significantly contribute to the uncertainty, along with the errors of the normal determination. A set of CLUSTER observed shocks is an…