Search Publications
The Abundance of Lead in Four Metal-poor Stars
Peterson, Ruth C.
Cowan et al. review how roughly half the elements heavier than iron found in the Sun are produced by rapid neutron capture and half by slow neutron capture, the r- and s-processes. In the Sun, their relative contribution to individual elemental abundances is well understood, except for the lightest and heaviest elements beyond iron. Their contribu…
3D Parameter Maps of Red Clump Stars in the Milky Way: Absolute Magnitudes and Intrinsic Colors
Wang, Shu; Chen, Xiaodian
Red clump stars (RCs) are useful tracers of distances, extinction, chemical abundances, and Galactic structures and kinematics. Accurate estimation of RC parameters-absolute magnitude and intrinsic color-is the basis for obtaining high-precision RC distances. By combining astrometric data from Gaia; spectroscopic data from APOGEE and LAMOST; and m…
Touching the Stars: Using High-resolution 3D Printing to Visualize Stellar Nurseries
Forbes, John C.; Imara, Nia; Weaver, James C.
Owing to their intricate variable density architecture, and as a principal site of star formation, molecular clouds represent one of the most functionally significant, yet least understood features of our universe. To unravel the intrinsic structural complexity of molecular clouds, here we leverage the power of high-resolution bitmap-based three-d…
Morphological Transformation and Star Formation Quenching of Massive Galaxies at 0.5 ≤ z ≤ 2.5 in 3D-HST/CANDELS
Fang, Guanwen; Gu, Yizhou; Yuan, Qirong +4 more
To figure out the effect of stellar mass and local environment on morphological transformation and star formation quenching in galaxies, we use the massive (M * ≥ 1010 M ⊙) galaxies at 0.5 ≤ z ≤ 2.5 in five fields of 3D-HST/CANDELS. Based on the UVJ diagnosis and the possibility of possessing a spheroid, our sample…
The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula
Kalari, Venu M.
The Trifid Nebula is a young, nearby star-forming region where star formation is proposed to have been triggered by cloud-cloud collision (CCC), based on observations of molecular clouds. It offers a unique opportunity to test whether the CCC hypothesis is supported by the spatial distribution and star formation chronology of young stars. We prese…
A VLA Survey of Late-time Radio Emission from Superluminous Supernovae and the Host Galaxies
Tamura, Yoichi; Tominaga, Nozomu; Hatsukade, Bunyo +5 more
We present the results of 3 GHz radio continuum observations of 23 superluminous supernovae (SLSNe) and their host galaxies by using the Karl G. Jansky Very Large Array conducted 5-21 yr after the explosions. The sample consists of 15 Type I and 8 Type II SLSNe at z < 0.3, providing one of the largest samples of SLSNe with late-time radio data.…
Tracking the Source of Solar Type II Bursts through Comparisons of Simulations and Radio Data
Kasper, Justin C.; Hegedus, Alexander M.; Manchester, Ward B.
The most intense solar energetic particle events are produced by coronal mass ejections (CMEs) accompanied by intense type II radio bursts below 15 MHz. Understanding where these type II bursts are generated relative to an erupting CME would reveal important details of particle acceleration near the Sun, but the emission cannot be imaged on Earth …
Possible Detection of X-Ray Emitting Circumstellar Material in the Synchrotron-dominated Supernova Remnant RX J1713.7-3946
Acero, Fabio; Katsuda, Satoru; Terada, Yukikatsu +4 more
We report on a discovery of an X-ray emitting circumstellar material (CSM) knot inside the synchrotron dominant supernova remnant RX J1713.7-3946. This knot was previously thought to be a Wolf-Rayet star (WR 85), but we realized that it is in fact ~40″ away from WR 85, indicating no relation to WR 85. We performed high-resolution X-ray spectroscop…
Disentangling the Physical Origin of Emission Line Ratio Offsets at High Redshift with Spatially Resolved Spectroscopy
Cooper, M. C.; Martin, Crystal L.; Treu, Tommaso +6 more
We present spatially resolved Hubble Space Telescope grism spectroscopy of 15 galaxies at z ~ 0.8 drawn from the DEEP2 survey. We analyze Hα+[N II], [S II], and [S III] emission on kiloparsec scales to explore which mechanisms are powering emission lines at high redshifts, testing which processes may be responsible for the well-known offset of hig…
Anomalous Hydrogen Recombination Line Ratios in Ultraluminous Infrared Galaxies
Nakagawa, Takao; Baba, Shunsuke; Isobe, Naoki +5 more
We conducted systematic observations of the H I Brα (4.05 µm) and Brβ (2.63 µm) lines in 52 nearby (z < 0.3) ultraluminous infrared galaxies (ULIRGs) with AKARI. Among 33 ULIRGs wherein the lines are detected, 3 galaxies show anomalous Brβ/Brα line ratios (~1.0), which are significantly higher than those for case B (0.565). Our obse…