Search Publications
Spin Parity of Spiral Galaxies. I. Corroborative Evidence for Trailing Spirals
Tadaki, Ken-ichi; Iye, Masanori; Fukumoto, Hideya
Whether the spiral structure of galaxies is trailing or leading has been a subject of debate. We present a new spin parity catalog of 146 spiral galaxies that lists the following three pieces of information: whether the spiral structure observed on the sky is S-wise or Z-wise; which side of the minor axis of the galaxy is darker and redder, based …
Manifestations of Three-dimensional Magnetic Reconnection in an Eruption of a Quiescent Filament: Filament Strands Turning to Flare Loops
Aulanier, Guillaume; Dudík, Jaroslav; Lörinčík, Juraj
We report on observations of the conversion of bright filament strands into flare loops during the 2012 August 31 filament eruption. Prior to the eruption, individual bright strands composing one of the legs of the filament were observed in the 171 Å filter channel data of the Atmospheric Imaging Assembly. After the onset of the eruption, one of t…
New Constraints on Early-type Galaxy Assembly from Spectroscopic Metallicities of Globular Clusters in M87
Romanowsky, Aaron J.; Strader, Jay; Brodie, Jean +1 more
The observed characteristics of globular cluster (GC) systems, such as metallicity distributions, are commonly used to place constraints on galaxy formation models. However, obtaining reliable metallicity values is particularly difficult because of our limited means to obtain high quality spectroscopy of extragalactic GCs. Often, “color-metallicit…
The Cold Circumgalactic Environment of MAMMOTH-I: Dynamically Cold Gas in the Core of an Enormous Lyα Nebula
Prochaska, J. Xavier; Lehnert, Matthew D.; Cai, Zheng +2 more
The MAMMOTH-I Nebula at redshift 2.3 is one of the largest known Lyα nebulae in the universe, spanning ∼440 kpc. Enormous Lyα nebulae like MAMMOTH-I typically trace the densest and most active regions of galaxy formation. Using sensitive low-surface-brightness observations of CO(1-0) with the Very Large Array, we trace the cold molecular gas in th…
Infrared Spectroscopy of Symbiotic Stars. XII. The Neutron Star SyXB System 4U 1700+24 = V934 Herculis
Mikołajewska, Joanna; Fekel, Francis C.; Hinkle, Kenneth H. +3 more
The X-ray symbiotic (SyXB) V934 Her = 4U 1700+24 is an M giant-neutron star (NS) binary system. Employing optical and infrared radial velocities spanning 29 yr combined with the extensive velocities in the literature, we compute the spectroscopic orbit of the M giant in that system. We determine an orbital period of 4391 days, or 12.0 yr, the long…
Molecular Cloud Distances Based on the MWISP CO Survey and Gaia DR2
Xu, Ye; Su, Yang; Yan, Qing-Zeng +2 more
We present a new method of calculating distances of molecular clouds in the Galactic plane, using CO observations and the Gaia DR2 parallax and G-band extinction (A G ) measurements. Due to the complexity of dust environments in the Galactic plane, A G contains irregular variations, which are difficult to model. To overcom…
Probing ISM Structure in Trumpler 14 and Carina I Using the Stratospheric Terahertz Observatory 2
van der Tak, Floris F. S.; Tolls, Volker; Horiuchi, Shinji +26 more
We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2. The Trumpler 14/Carina I region is in the western part of the Carina Nebula Complex (CNC), which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 µm transition of…
Stellar Overdensity in the Local Arm in Gaia DR2
Matsunaga, Noriyuki; Kawata, Daisuke; Honma, Mareki +4 more
Using the cross-matched data of Gaia DR2 and the 2MASS Point Source Catalog, we investigated the surface density distribution of stars aged ∼1 Gyr in the thin disk in the range of 90° ≤ l ≤ 270°. We selected 4654 stars above the turnoff corresponding to the age ∼1 Gyr, that fall within a small box region in the color-magnitude diagram, (J - K
Examining the Class B to A Shift of the 7.7 µm PAH Band with the NASA Ames PAH IR Spectroscopic Database
Boersma, Christiaan; Shannon, Matthew J.
We present insights into the behavior of the astronomical 7.7 µm polycyclic aromatic hydrocarbon (PAH) emission complex as gleaned from analyzing synthesized spectra, utilizing the data and tools from the NASA Ames PAH IR Spectroscopic Database. We specifically study the influence of PAH size, charge, aliphatic content, and nitrogen substitu…
Serendipitous Discovery of PSR J1431-6328 as a Highly Polarized Point Source with the Australian SKA Pathfinder
Kaplan, David L.; Kaczmarek, Jane F.; Swiggum, Joseph K. +10 more
We identified a highly polarized, steep-spectrum radio source in a deep image with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope at 888 MHz. After considering and rejecting a stellar origin for this source, we discovered a new millisecond pulsar (MSP) using observations from the Parkes radio telescope. This pulsar has period 2…