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The Three-dimensional Orbit and Physical Parameters of 47 Oph
Wang, Xiaoli; Ren, Shulin; Fu, Yanning +1 more
Although 47 Oph has been shown to be a binary with a period of ∼27 days using both spectroscopic and interferometric techniques, only a preliminary orbit has been obtained in the previous work due to the shortage of high precision measurements. Since 1997, new spectroscopic and interferometric measurements have been obtained with much higher preci…
A Starburst in the Core of a Galaxy Cluster: the Dwarf Irregular NGC 1427A in Fornax
Puzia, Thomas H.; Chanamé, Julio; Mora, Marcelo D.
Gas-rich galaxies in dense environments such as galaxy clusters and massive groups are affected by a number of possible types of interactions with the cluster environment, which make their evolution radically different than that of field galaxies. The dwarf irregular galaxy NGC 1427A, presently infalling toward the core of the Fornax galaxy cluste…
HD 207651: a Composite Spectrum Triple System
Fekel, Francis C.
From numerous radial velocities obtained at KPNO and Fairborn Observatory, we have determined the orbital elements of the composite spectrum triple system HD 207651. This system consists of a broad-lined A8 V star and an unseen M dwarf companion in a 1.470739 days orbit. Variations of the center-of-mass velocity of this short-period system and vel…
A Statistical Study of H I Gas in Nearby Narrow-Line AGN-Hosting Galaxies
Wu, Hong; Zhu, Yi-Nan
As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (MH i), stellar mass (M*), and H i-to-stellar mass ratio (MH i
Source-plane Reconstruction of the Giant Gravitational Arc in A2667: A Candidate Wolf-Rayet Galaxy at z ~ 1
Richard, Johan; Izzo, Luca; Jullo, Eric +3 more
We present a new analysis of Hubble Space Telescope, Spitzer Space Telescope, and Very Large Telescope imaging and spectroscopic data of a bright lensed galaxy at z = 1.0334 in the lensing cluster A2667. Using this high-resolution imaging, we present an updated lens model that allows us to fully understand the lensing geometry and reconstruct the …
Self-consistent Orbits and Physical Properties for Eight Single-lined Spectroscopic Binaries
Wang, Xiaoli; Ren, Shulin; Fu, Yanning
For single-lined spectroscopic binaries (SB1s), self-consistent orbits can be determined via a simultaneous fit including both radial velocity data and the Hipparcos Intermediate Astrometric Data. Using the ratio λ of the semimajor axes of the photocenter to the primary orbits, the present paper develops an iterative fitting method. First, an init…
UBVRI Analysis of the Totally Eclipsing Extreme Mass Ratio W UMa Binary, GSC 3208 1986
Van Hamme, W.; Robb, Russell; Samec, R. G. +2 more
GSC 3208 1986 is an NSVS and TYCHO binary, first observed from 1999 to 2000. It is a W UMa binary with a period of 0.405 days. The present observations were taken in 2012 September and are of high precision, averaging a standard deviation of better than 5 mmag. The amplitude of the light curve is very nearly 0.5 mag yet it undergoes total eclipses…
The Identification of Extreme Asymptotic Giant Branch Stars and Red Supergiants in M33 With 24 µm Variability
Clayton, Geoffrey C.; Engelbracht, Charles W.; Srinivasan, Sundar +2 more
We present the first detection of 24 µm variability in 24 sources in the Local Group galaxy M33. These results are based on 4 epochs of Multiband Imaging Photometer for Spitzer observations, which are irregularly spaced over ∼ 750 days. We find that these sources are constrained exclusively to the Holmberg radius of the galaxy, which increas…
Application of Vector Spherical Harmonics and Kernel Regression to the Computations of OMM Parameters
Marco, F. J.; Martínez, M. J.; López, J. A.
The high quality of Hipparcos data in position, proper motion, and parallax has allowed for studies about stellar kinematics with the aim of achieving a better physical understanding of our galaxy, based on accurate calculus of the Ogorodnikov-Milne model (OMM) parameters. The use of discrete least squares is the most common adjustment method, but…
Structural Parameters for 10 Halo Globular Clusters in M33
Ma, Jun
In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5-7 × 105 L⊙ in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, …