Search Publications
Flare and Warp of Galactic Disk with OB Stars from Gaia DR2
Zhao, Gang; Li, Chengdong; Yang, Chengqun +3 more
The OB stars are selected from the Gaia DR2 catalog to explore the flare and warp of the Galactic disk in this work. The Gaia and 2MASS photometric information is adopted as the criteria to choose the sample stars. We model the Galactic disk stellar distribution in this work taking the flare and warp into consideration. The parameters in the flare…
An Extremely Low-mass He White Dwarf Orbiting the Millisecond Pulsar J1342+2822B in the Globular Cluster M3
Ferraro, F. R.; Lanzoni, B.; Pallanca, C. +3 more
We report on the discovery of the companion star to the millisecond pulsar J1342+2822B in the globular cluster M3. We exploited a combination of near-ultraviolet and optical observations acquired with the Hubble Space Telescope in order to search for the optical counterparts to the known millisecond pulsars in this cluster. At a position in excell…
[C I](1-0) and [C I](2-1) in Resolved Local Galaxies
Hunt, Leslie K.; Wilson, Christine D.; Rosolowsky, Erik +16 more
We present resolved [C I] line intensities of 18 nearby galaxies observed with the SPIRE FTS spectrometer on the Herschel Space Observatory. We use these data along with resolved CO line intensities from J up = 1 to 7 to interpret what phase of the interstellar medium the [C I] lines trace within typical local galaxies. A tight, linear …
Galactic Rotation and the Oort Constants in the Solar Vicinity
Zhao, Gang; Li, Chengdong; Yang, Chengqun
Gaia DR2 data are used to calculate the Oort constants and derive the Galactic rotational properties in this work. We choose the solar vicinity stars with a “clean” sample within 500 pc. The Oort constants are then fitted through the relation between the proper motions as a function of Galactic longitude l. A maximum likelihood method is adopted t…
Spectral and Timing Analysis of the Accretion-powered Pulsar 4U 1626-67 Observed with Suzaku and NuSTAR
Enoto, Teruaki; Chakrabarty, Deepto; Terada, Yukikatsu +13 more
We present an analysis of the spectral shape and pulse profile of the accretion-powered pulsar 4U 1626-67 observed with Suzaku and Nuclear Spectroscopic Telescope Array (NuSTAR) during a spin-up state. The pulsar, which experienced a torque reversal to spin-up in 2008, has a spin period of ∼7.7 s. Comparing the phase-averaged spectra obtained with…
Distances to Galactic OB Stars: Photometry versus Parallax
Shull, J. Michael; Danforth, Charles W.
For application to surveys of interstellar matter and Galactic structure, we compute new spectrophotometric distances to 139 OB stars frequently used as background targets for UV spectroscopy. Many of these stars have updated spectral types and digital photometry with reddening corrections from the Galactic O-Star (GOS) spectroscopic survey. We co…
On the Origin of Solar Torsional Oscillations and Extended Solar Cycle
Kosovichev, A. G.; Pipin, V. V.
We present a nonlinear mean-field model of the solar interior dynamics and dynamo, which reproduces the observed cyclic variations of the global magnetic field of the Sun, as well as the differential rotation and meridional circulation. Using this model, we explain, for the first time, the extended 22 yr pattern of the solar torsional oscillations…
Detecting Thin Stellar Streams in External Galaxies: Resolved Stars and Integrated Light
Williams, Benjamin F.; Ibata, Rodrigo A.; Johnston, Kathryn V. +3 more
The morphology of thin stellar streams can be used to test the nature of dark matter. It is therefore crucial to extend searches for globular cluster (GC) streams to other galaxies than the Milky Way. In this paper, we investigate the current and future prospects of detecting GC streams in external galaxies in resolved stars (e.g., with Wide Field…
Stellar Mass Growth of Brightest Cluster Galaxy Progenitors in COSMOS Since z ∼ 3
Casey, Caitlin M.; Kartaltepe, Jeyhan S.; Le Fèvre, Olivier +5 more
We examine the role of environment on the in situ star formation (SF) hosted by the progenitors of the most massive galaxies in the present-day universe, the brightest cluster galaxies (BCGs), from z ∼ 3 to present in the COSMOS field. Progenitors are selected from the COSMOS field using a stellar mass cut motivated by the evolving cumulative como…
An Enormous Molecular Gas Flow in the RX J0821+0752 Galaxy Cluster
Fabian, A. C.; Combes, F.; McDonald, M. +6 more
We present recent Chandra X-ray observations of the RX J0821.0+0752 galaxy cluster, in addition to ALMA observations of the CO(1-0) and CO(3-2) line emission tracing the molecular gas in its central galaxy. All of the CO line emission, originating from a {10}10 {M}⊙ molecular gas reservoir, is located several kiloparsecs awa…