Search Publications
The Magnetic Field in the Milky Way Filamentary Bone G47
Jackson, James M.; Sanhueza, Patricio; Guzmán, Andrés +21 more
Star formation primarily occurs in filaments where magnetic fields are expected to be dynamically important. The largest and densest filaments trace the spiral structure within galaxies. Over a dozen of these dense (~104 cm-3) and long (>10 pc) filaments have been found within the Milky Way, and they are often referred to …
The (Black Hole Mass)-(Spheroid Stellar Density) Relations: M BH-µ (and M BH-Σ) and M BH-ρ
Graham, Alister W.; Davis, Benjamin L.; Sahu, Nandini
This paper is the fourth in a series presenting (galaxy morphology, and thus galaxy formation)-dependent black hole (BH) mass, M BH, scaling relations. We have used a sample of 119 galaxies with directly measured M BH and host spheroid parameters obtained from multicomponent decomposition of, primarily, 3.6 µm Spitzer i…
Peculiar Radio-X-Ray Relationship in Active Stars
Ray, T. P.; Callingham, J. R.; Shimwell, T. W. +5 more
The empirical relationship between the nonthermal 5 GHz radio luminosity and the soft X-ray luminosity of active stellar coronae, canonically called the Güdel-Benz relationship, has been a cornerstone of stellar radio astronomy, as it explicitly ties the radio emission to the coronal heating mechanisms. The relationship extends from microflares on…
EXORCISM: A Spectroscopic Survey of Young Eruptive Variables (EXor and Candidates)
Rossi, A.; Testa, V.; Lorenzetti, D. +9 more
We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ( ${\mathfrak{R}}\sim 1500\mbox{--}2000$ ) were collected between 2014 and 2019 with the Large Binocular Telescope (LBT). From the spectral analysis we h…
A Population of Luminous Globular Clusters and Stripped Nuclei with Elevated Mass to Light Ratios around NGC 5128
Forbes, Duncan A.; Caldwell, Nelson; Strader, Jay +8 more
The dense central regions of tidally disrupted galaxies can survive as ultracompact dwarfs (UCDs) that hide among the luminous globular clusters (GCs) in the halo of massive galaxies. An exciting confirmation of this model is the detection of overmassive black holes in the centers of some UCDs, which also lead to elevated dynamical mass-to-light r…
Observations of a Flare-ignited Broad Quasiperiodic Fast-propagating Wave Train
Liu, Ying D.; Hu, Huidong; Shen, Yuandeng +6 more
Large-scale extreme-ultraviolet (EUV) waves are frequently observed as an accompanying phenomenon of flares and coronal mass ejections (CMEs). Previous studies mainly focused on EUV waves with single wave fronts that are generally thought to be driven by the lateral expansion of CMEs. Using high spatiotemporal resolution multi-angle imaging observ…
Variable Stars in the Giant Satellite Galaxy Antlia 2
Erkal, Denis; Belokurov, Vasily; Li, Ting S. +3 more
We report 350 pulsating variable stars found in four DECam fields (~12 deg2) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids in the galaxy. Reclassification of several objects designated previously to be RR Lyrae as anomalous Cepheids get rid of the satellite's sta…
Pearls on a String: Numerous Stellar Clusters Strung Along the Same Orbit
Rix, Hans-Walter; Fürnkranz, Verena; Coronado, Johanna
Stars originate from the dense interstellar medium, which exhibits filamentary structure to scales of ~1 kpc in galaxies like our Milky Way. We explore quantitatively how much resulting large-scale correlation there is among different stellar clusters and associations in orbit-phase space, characterized here by actions and angles. As a starting po…
Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-field Model
Peter, Annika H. G.; Beacom, John F.; Li, Jung-Tsung
A key goal of heliophysics is to understand how cosmic rays propagate in the solar system's complex, dynamic environment. One observable is solar modulation, i.e., how the flux and spectrum of cosmic rays change as they propagate inward. We construct an improved force-field model, taking advantage of new measurements of magnetic power spectral den…
The Ultramassive White Dwarfs of the Alpha Persei Cluster
Caiazzo, Ilaria; Richer, Harvey B.; Heyl, Jeremy +2 more
We searched through the entire Gaia EDR3 candidate white dwarf catalog for stars with proper motions and positions that are consistent with them having escaped from the Alpha Persei cluster within the past 81 Myr, the age of the cluster. In this search we found five candidate white dwarf escapees from Alpha Persei and obtained spectra for all of t…