Search Publications
Comparison of the Asteroseismic Mass Scale of Red Clump Giants with Photometric Mass Estimates
Pinsonneault, Marc H.; Terndrup, Donald M.; Chung, Chul +1 more
Asteroseismology can provide joint constraints on masses and radii of individual stars. While this approach has been extensively tested for red giant branch (RGB) stars, it has been more difficult to test for helium core-burning red clump (RC) giants because of the lack of fundamental calibrators. To provide independent mass estimates, we utilize …
SOFIA/FORCAST Observations of the Sgr A-H H II Regions: Using Dust Emission to Elucidate the Heating Sources
Morris, M. R.; Mills, E. A. C.; Lau, R. M. +2 more
The Sgr A-H H II regions are a collection of sources that may represent one of the most recent sites of star formation in the Galactic center (GC). Examining these H II regions provides important information on the prevalence and distribution of massive stars in the region and may provide clues on the origin of other massive field stars throughout…
Modeling the Spatial Distribution and Origin of CO Gas in Debris Disks
Gorti, Uma; Carpenter, John M.; Hales, A. S. +2 more
The detection of gas in debris disks raises the question of whether this gas is a remnant from the primordial protoplanetary phase, or released by the collision of secondary bodies. In this paper we analyze ALMA observations at 1″-1.″5 resolution of three debris disks where the 12CO(2-1) rotational line was detected: HD 131835, HD 13881…
Gemini Imaging of the Host Galaxies of Changing-look Quasars
Anderson, Scott F.; Eracleous, Michael; Haggard, Daryl +4 more
Changing-look (CL) quasars are a newly discovered class of luminous active galactic nuclei that undergo rapid (≲10 yr) transitions between Type 1 and Type 1.9/2, with an associated change in their continuum emission. We characterize the host galaxies of four faded CL quasars using broadband optical imaging. We use gri images obtained with the Gemi…
Nonequilibrium Ionization Effects on Solar EUV and X-Ray Imaging Observations
Moon, Yong-Jae; Reeves, Katharine K.; Raymond, John C. +3 more
During transient events such as major solar eruptions, the plasma can be far from the equilibrium ionization state because of rapid heating or cooling. Nonequilibrium ionization (NEI) is important in rapidly evolving systems where the thermodynamical timescale is shorter than the ionization or recombination timescales. We investigate the effects o…
Luminosity Ratio between [O IV] 25.89 µm Line and Nuclear Continuum 12 µm as a Diagnostic for “Buried” AGNs
Imanishi, Masatoshi; Tanimoto, Atsushi; Ueda, Yoshihiro +3 more
We propose new diagnostics that utilize the [O IV] 25.89 µm and nuclear (subarcsecond scale) 12 µm luminosity ratios for identifying whether an active galactic nucleus (AGN) is deeply “buried” in their surrounding materials. Utilizing a sample of 16 absorbed AGNs at redshifts lower than 0.03 in the Swift/BAT catalog observed with Suzak…
HST F160W Imaging of Very Massive Galaxies at 1.5 < z < 3.0: Diversity of Structures and the Effect of Close Pairs on Number Density Estimates
Franx, Marijn; Muzzin, Adam; Labbé, Ivo +10 more
We present a targeted follow-up Hubble Space Telescope WFC3 F160W imaging study of very massive galaxies ({log}({M}star}/{M}⊙ )> 11.25) selected from a combination of ground-based near-infrared galaxy surveys (UltraVISTA, NEWFIRM Medium Band Survey-II , UKIRT Infrared Deep Sky Survey (UKIDSS) Ultra-Deep Survey (UDS) at 1.5…
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). IV. The Submillimeter Properties of X-Ray Sources in the CDF-S
Bauer, F. E.; Barger, A. J.; Cowie, L. L. +1 more
The Chandra Deep Field (CDF)-S is the deepest X-ray image available and will remain so for the near future. We provide a spectroscopic (64.5%; 64% with spectral classifications) and photometric redshift catalog for the full 7 Ms sample, but much of our analysis focuses on the central (off-axis angles <5.‧7) region, which contains a large, faint…
Forbush Decreases and <2 Day GCR Flux Non-recurrent Variations Studied with LISA Pathfinder
Mendes, L.; Russano, G.; Lloro, I. +82 more
Non-recurrent short-term variations of the galactic cosmic-ray (GCR) flux above 70 MeV n-1 were observed between 2016 February 18 and 2017 July 3 on board the European Space Agency LISA Pathfinder (LPF) mission orbiting around the Lagrange point L1 at 1.5 × 106 km from Earth. The energy dependence of three Forbush decreases i…
On the Origin of the Scatter in the Red Sequence: An Analysis of Four CLASH Clusters
Donahue, Megan; Kelson, Daniel D.; Moustakas, John +1 more
In clusters of galaxies, the red sequence is believed to be a consequence of a correlation between stellar mass and chemical abundances, with more massive galaxies being more metal-rich and, as a consequence, redder. However, there is a color scatter around the red sequence that holds even with precision photometry, implying that the galaxy popula…