Search Publications
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…
Compton-thick AGNs in the NuSTAR Era. II. A Deep NuSTAR and XMM-Newton View of the Candidate Compton-thick AGN in NGC 1358
Cusumano, G.; Vignali, C.; Ajello, M. +4 more
We present the combined NuSTAR and XMM-Newton 0.6-79 keV spectral analysis of a Seyfert 2 galaxy, NGC 1358, which we selected as a candidate Compton-thick (CT) active galactic nucleus (AGN) on the basis of previous Swift/BAT and Chandra studies. According to our analysis, NGC 1358 is confirmed to be a CT-AGN using physically motivated models, at &…
A Reanalysis of the Fundamental Parameters and Age of TRAPPIST-1
Gonzales, Eileen C.; McWilliam, Andrew; Teske, Johanna +3 more
We present the distance-calibrated spectral energy distribution (SED) of TRAPPIST-1 using a new medium-resolution (R ∼ 6000) near-infrared (NIR) Folded-port InfraRed Echellette (FIRE) spectrum and its Gaia parallax. We report an updated bolometric luminosity (L bol) of -3.216 ± 0.016, along with semiempirical fundamental parameters: eff…
Precision Distances to Dwarf Galaxies and Globular Clusters from Pan-STARRS1 3π RR Lyrae
Rix, Hans-Walter; Magnier, Eugene; Kudritzki, Rolf-Peter +6 more
We present new spatial models and distance estimates for globular clusters and dwarf spheroidals orbiting our Galaxy based on RR Lyrae (RRab) stars in the Pan-STARRS1 (PS1) 3π survey. Using the PS1 sample of RRab stars from Sesar et al. in 16 globular clusters and 5 dwarf galaxies, we fit structural models in (l, b, D) space; for 13 globular clust…