Search Publications
CO-DARK Star Formation and Black Hole Activity in 3C 368 at Z = 1.131: Coeval Growth of Stellar and Supermassive Black Hole Masses
Riechers, D.; Stacey, G.; Lamarche, C. +7 more
We present the detection of four far-infrared fine-structure oxygen lines, as well as strong upper limits for the CO(2-1) and [N II] 205 µm lines, in 3C 368, a well-studied radio-loud galaxy at z = 1.131. These new oxygen lines, taken in conjunction with previously observed neon and carbon fine-structure lines, suggest a powerful active gala…
An Incipient Debris Disk in the Chamaeleon I Cloud
Hernández, J.; Ribas, Á.; McClure, M. K. +5 more
The point at which a protoplanetary disk becomes a debris disk is difficult to identify. To better understand this, here we study the ∼40 au separation binary T 54 in the Chamaeleon I cloud. We derive a K5 spectral type for T 54 A (which dominates the emission of the system) and an age of ∼2 Myr. However, the dust disk properties of T 54 are consi…
High-resolution X-Ray Spectroscopy of the Seyfert 1 Galaxy Mrk 1040. Revealing the Failed Nuclear Wind with Chandra
Behar, E.; Turner, T. J.; Kraemer, S. B. +6 more
High-resolution X-ray spectroscopy of the warm absorber in the nearby X-ray bright Seyfert 1 galaxy Mrk 1040 is presented. The observations were carried out in the 2013-2014 timeframe using the Chandra High Energy Transmission Grating with a total exposure of 200 ks. A multitude of absorption lines from Ne, Mg, and Si are detected from a wide vari…
JVLA Observations of IC 342: Probing Star Formation in the Nucleus
Goss, W. M.; Johnson, K. E.; Kepley, Amanda A. +2 more
IC 342 is a nearby, late-type spiral galaxy with a young nuclear star cluster surrounded by several giant molecular clouds. The IC 342 nuclear region is similar to the Milky Way and therefore provides an interesting comparison. We explore star formation in the nucleus using radio recombination line (RRL) and continuum emission at 5, 6.7, 33, and 3…
A SOFIA FORCAST Grism Study of the Mineralogy of Dust in the Winds of Proto-planetary Nebulae: RV Tauri Stars and SRd Variables
Gehrz, R. D.; Lebzelter, T.; Hinkle, K. H. +10 more
We present a SOFIA FORCAST grism spectroscopic survey to examine the mineralogy of the circumstellar dust in a sample of post-asymptotic giant branch (post-AGB) yellow supergiants that are believed to be the precursors of planetary nebulae. Our mineralogical model of each star indicates the presence of both carbon-rich and oxygen-rich dust species…
Probing Large Galaxy Halos at Z ∼ 0 with Automated Lyα-absorption Matching
Wakker, Bart P.; French, David M.
We present initial results from an ongoing large-scale study of the circumgalactic medium in the nearby Universe ({cz} ≤slant 10,000 {km} {{{s}}}-1), using archival Cosmic Origins Spectrograph spectra of background quasi-stellar objects. This initial sample contains 33 sightlines chosen for their proximity to large galaxies (D≥slant 25 …
Computation of the Transmitted and Polarized Scattered Fluxes by the Exoplanet HD 189733b in X-Rays
Marin, Frédéric; Grosso, Nicolas
Thousands of exoplanets have been detected, but only one exoplanetary transit was potentially observed in X-rays from HD 189733A. What makes the detection of exoplanets so difficult in this band? To answer this question, we run Monte-Carlo radiative transfer simulations to estimate the amount of X-ray flux reprocessed by HD 189733b. Despite its ex…
A Bayesian Approach to Period Searching in Solar Coronal Loops
McKenzie, David; Scherrer, Bryan
We have applied a Bayesian generalized Lomb-Scargle period searching algorithm to movies of coronal loop images obtained with the Hinode X-ray Telescope (XRT) to search for evidence of periodicities that would indicate resonant heating of the loops. The algorithm makes as its only assumption that there is a single sinusoidal signal within each lig…
Discovery of a Rapid, Luminous Nova in NGC 300 by the KMTNet Supernova Program
Kim, Dong-Jin; Lee, Yongseok; Moon, Dae-Sik +3 more
We present the discovery of a rapidly evolving transient by the Korean Microlensing Telescope Network Supernova Program (KSP). KSP is a novel high-cadence supernova survey that offers deep (∼21.5 mag in BV I bands), nearly continuous wide-field monitoring for the discovery of early and/or fast optical transients. KSP-OT-201509a, reported here, was…
The Evolution of Bulge-dominated Field Galaxies from z ≈ 1 to the Present
Jørgensen, Inger; Woodrum, Charity; Demarco, Ricardo +4 more
We analyze the stellar populations and evolutionary history of bulge-dominated field galaxies at redshifts 0.3< z< 1.2 as part of the Gemini/Hubble Space Telescope (HST) Galaxy Cluster Project (GCP). High signal-to-noise optical spectroscopy from the Gemini Observatory and imaging from the HST are used to analyze a total of 43 galaxies, focu…