Search Publications
Modeling of Spiral Structure in a Multi-Component Milky Way-Like Galaxy
Korchagin, Vladimir; Khrapov, Sergey; Khoperskov, Alexander
Using recent observational data, we construct a set of multi-component equilibrium models of the disk of a Milky Way-like galaxy. The disk dynamics are studied using collisionless-gaseous numerical simulations, based on the joined integration of the equations of motion for the collision-less particles using direct integration of gravitational inte…
AGN Triality of Triple Mergers: Multiwavelength Classifications
Gültekin, Kayhan; Runnoe, Jessie C.; Foord, Adi +1 more
We present results from a multiwavelength analysis searching for multiple active galactic nucleus (AGN) systems in nearby (z < 0.077) triple galaxy mergers. Combining archival Chandra, Sloan Digital Data Survey (SDSS), Wide-field Infrared Survey Explorer (WISE), and Very Large Array observations, we quantify the rate of nearby triple AGNs, as w…
Fine Structures of an EUV Wave Event from Multi-viewpoint Observations
Moon, Yong-Jae; Chen, P. F.; Schmieder, Brigitte +4 more
In this study, we investigate an extreme ultraviolet (EUV) wave event on 2010 February 11, which occurred as a limb event from the Earth viewpoint and a disk event from the Solar Terrestrial Relations Observatory-Behind viewpoint. We use the data obtained by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory in various EUV ch…
A partial Lyman limit system tracing intragroup gas at z ≈ 0.8 towards HE 1003 + 0149
Charlton, Jane C.; Johnson, Sean D.; Sameer +6 more
We present analysis of the galaxy environment and physical properties of a partial Lyman limit system at z = 0.83718 with H I and metal-line components closely separated in redshift space (|Δv| ≈ 400 km s-1) towards the background quasar HE 1003 + 0149. The HST/COS far-ultraviolet spectrum provides coverage of lines of oxygen ions from …
Outflows from GRB hosts are ubiquitous: Kinematics of z < 0.3 GRB-SN hosts resolved with FLAMES
Covino, S.; Della Valle, M.; Melandri, A. +12 more
The hosts of long duration gamma-ray bursts (GRBs) are predominantly starburst galaxies at subsolar metallicity. At redshifts z < 1, this implies that most of them are low-mass galaxies similar to the populations of blue compact dwarfs and dwarf irregulars. What triggers the massive star-formation needed for producing a GRB progenitor is still …
The composite X-ray spectra of radio-loud and radio-quiet SDSS quasars
Gu, Min-Feng; Zhou, Min-Hua
We present a study of the X-ray emission for a sample of radio-detected quasars constructed from the cross-matches between SDSS, FIRST catalogs and XMM-Newton archives. A sample of radio-quiet SDSS quasars without FIRST radio detection is also assembled for comparison. We construct the optical and X-ray composite spectra normalized at rest frame 4…
A search for optical laser emission from Proxima Centauri
Marcy, G. W.
A search for laser light from Proxima Centauri was performed, including 107 high-resolution, optical spectra obtained between 2004 and 2019 with the HARPS spectrometer. The search for laser light involved rejecting sharp peaks in the spectrum from stellar flares, fluorescent city lights, and elementary particles that directly hit the CCD detector.…
Chandra and HST studies of six millisecond pulsars in the globular cluster M13
Zhao, Jiaqi; Heinke, Craig O.; Zhao, Yue
We analyse 55 ks of Chandra X-ray observations of the Galactic globular cluster (GC) M13. Using the latest radio timing positions of six known millisecond pulsars (MSPs) in M13 from Wang et al. (2020), we detect confident X-ray counterparts to five of the six MSPs at X-ray luminosities of LX(0.3-8 keV)∼3 × 1030-1031
The MOSDEF survey: the dependence of H α-to-UV SFR ratios on SFR and size at z 2
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +12 more
We perform an aperture-matched analysis of dust-corrected H α and UV star formation rates (SFRs) using 303 star-forming galaxies with spectroscopic redshifts 1.36 < zspec < 2.66 from the MOSFIRE Deep Evolution Field survey. By combining H α and H β emission line measurements with multiwaveband resolved Cosmic Assembly Near-infrare…
Properties of the Hyades, the eclipsing binary HD 27130, and the oscillating red giant ɛ Tauri
Snellen, I. A. G.; Grundahl, F.; Fredslund Andersen, M. +21 more
Context. The derivation of accurate and precise masses and radii is possible for eclipsing binary stars, allowing for insights into their evolution. When residing in star clusters, they provide measurements of even greater precision, along with additional information on their properties. Asteroseismic investigations of solar-like oscillations offe…