Search Publications
Detection of Periodicity in SiO Maser Intensity and Velocity Shift of the Symbiotic Star CH Cyg
Kim, Dong-Jin; Kim, Jaeheon; Cho, Se-Hyung +3 more
We performed simultaneous monitoring observations of H2O 616-523 and SiO V = 1, 2, $J=1\to $ 0, SiO V = 1, $J=2\to $ 1, $3\to 2$ maser lines toward the symbiotic star CH Cyg from 2012 December to 2019 November using the Korean very long baseline interferometry Network single-dish telescope. SiO V = 1, 2, $J=1\to 0$…
Quasiperiodic Velocity Fluctuations in Eruptive Prominences Observed by AIA/SDO
Tsvetkov, Tsvetan; Petrov, Nikola
The current study presents an investigation of the behavior of prominences during eruptions. Variations in the distribution of their velocities are detected at altitudes <0.6 R⊙. Detailed analyses are carried out for 304 Å Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) observations. To track the behavior of promine…
Absolute Dimensions of the Unevolved F-type Eclipsing Binary BT Vulpeculae
Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W. +1 more
We report extensive differential V-band photometry and high-resolution spectroscopy for the 1.14 day, detached, double-lined eclipsing binary BT Vul (F0+F7). Our radial-velocity monitoring and light-curve analysis lead to absolute masses and radii of ${M}_{1}=1.5439\pm 0.0098\,{{ \mathcal M }}_{\odot }^{{\rm{N}}}$ and ${R}_{1}=1.536\pm 0.018\,{{ \…
LSST: From Science Drivers to Reference Design and Anticipated Data Products
Aubourg, Éric; Strauss, Michael A.; Anderson, Scott F. +324 more
We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way. LSST will be a large, wide-fiel…
Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics beyond ΛCDM
Casertano, Stefano; Riess, Adam G.; Yuan, Wenlong +2 more
We present an improved determination of the Hubble constant from Hubble Space Telescope (HST) observations of 70 long-period Cepheids in the Large Magellanic Cloud (LMC). These were obtained with the same WFC3 photometric system used to measure extragalactic Cepheids in the hosts of SNe Ia. Gyroscopic control of HST was employed to reduce overhead…
PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
Harding, A. K.; Ray, P. S.; Wood, K. S. +18 more
Neutron stars are not only of astrophysical interest, but are also of great interest to nuclear physicists because their attributes can be used to determine the properties of the dense matter in their cores. One of the most informative approaches for determining the equation of state (EoS) of this dense matter is to measure both a star’s equatoria…
A 3D Dust Map Based on Gaia, Pan-STARRS 1, and 2MASS
Speagle, Joshua S.; Zucker, Catherine; Finkbeiner, Douglas +2 more
We present a new three-dimensional map of dust reddening, based on Gaia parallaxes and stellar photometry from Pan-STARRS 1 and 2MASS. This map covers the sky north of a decl. of -30°, out to a distance of a few kiloparsecs. This new map contains three major improvements over our previous work. First, the inclusion of Gaia parallaxes dramatically …
The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +10 more
We present a new and independent determination of the local value of the Hubble constant based on a calibration of the tip of the red giant branch (TRGB) applied to Type Ia supernovae (SNe Ia). We find a value of H 0 = 69.8 ± 0.8 (±1.1% stat) ± 1.7 (±2.4% sys) km s-1 Mpc-1. The TRGB method is both precise and accur…
The Optical to Mid-infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS, and WISE Surveys
Wang, Shu; Chen, Xiaodian
A precise interstellar dust extinction law is critically important to interpret observations. There are two indicators of extinction: the color excess ratio (CER) and the relative extinction. Compared to the CER, the wavelength-dependent relative extinction is more challenging to be determined. In this work, we combine spectroscopic, astrometric, …
The Circular Velocity Curve of the Milky Way from 5 to 25 kpc
Hogg, David W.; Rix, Hans-Walter; Ness, Melissa K. +1 more
We measure the circular velocity curve v c(R) of the Milky Way with the highest precision to date across Galactocentric distances of 5 ≤ R ≤ 25 kpc. Our analysis draws on the six-dimensional phase-space coordinates of ≳23,000 luminous red giant stars, for which we previously determined precise parallaxes using a data-driven model that c…