Search Publications
GBT/Argus Observations of Molecular Gas in the Inner Regions of IC 342
Bolatto, Alberto D.; Leroy, Adam K.; Rosolowsky, Erik +9 more
We report observations of the ground state transitions of 12CO, 13CO, C18O, HCN, and HCO+ at 88–115 GHz in the inner region of the nearby galaxy IC 342. These data were obtained with the 16 pixel spectroscopic focal plane array Argus on the 100 m Robert C. Byrd Green Bank Telescope (GBT) at 6″–9″ resolut…
X-Rays from the Nearby Compact Emission-line Galaxy NGC 2366
Kaaret, Philip; Prestwich, Andrea
Luminous, compact emission-line galaxies (LCGs) are the most abundant class of confirmed Lyman continuum (LyC) emitters. An optical integral field study of the nearby LCG NGC 2366 reveals an outflow originating at the star cluster "knot B" thought to clear a channel via mechanical feedback that enables LyC escape. We observed NGC 2366 with the Cha…
Revisiting Physical Parameters of the Benchmark Brown Dwarf LHS 6343 C through a Hubble Space Telescope/WFC3 Secondary-eclipse Observation
Montet, Benjamin T.; Gagné, Jonathan; Albert, Loïc +7 more
The LHS 6343 system consists of a resolved M-dwarf binary with an evolved, negligibly irradiated brown dwarf (BD), LHS 6343 C, orbiting the primary star. Such BD eclipsing binaries present rare and unique opportunities to calibrate substellar evolutionary and atmosphere models since mass, radius, temperature, and luminosity can be directly measure…
Evolving Outer Heliosphere: Tracking Solar Wind Transients from 1 au to the VLISM with IBEX and Voyager 1
Reisenfeld, D. B.; McComas, D. J.; Rankin, J. S. +5 more
Interstellar Boundary Explorer (IBEX) observations of energetic neutral atom (ENA) fluxes from the heliosphere have greatly enriched our understanding of the interaction of the solar wind (SW) with the local interstellar medium (LISM). However, there has been recent controversy surrounding the inability of most ENA models to produce as high an int…
White Dwarf Photospheric Abundances in Cataclysmic Variables. IV. Deriving the [N/C] Ratio
Sion, Edward M.; Godon, Patrick
We present results from our ongoing far-ultraviolet archival analysis of cataclysmic variable white dwarf (WD) abundances for six more systems: four SU UMa dwarf novae (BW Scl, SW UMa, BC UMa, and VW Hyi) together with the dwarf nova RX And, and the novalike DW UMa. To derive a reliable nitrogen abundance, for the four SU UMa systems (with a WD te…
Identifying and Characterizing Infrared Excesses in the Spitzer Kepler Survey (SpiKeS)
Gorjian, Varoujan; Bryden, Geoffrey; Werner, Michael W. +2 more
We report our search for infrared excesses in the Spitzer/Infrared Array Camera survey of the Kepler field at 3.6 and 4.5 µm. The Spitzer Kepler Survey contains ∼190,000 targets, which we reduce to ∼117,000 targets after applying multiple filters to arrive at a high-quality sample for spectral energy distribution fitting. Of the ∼117,000, we…
Fe/O Variations Relative to Source Longitude and Heliospheric Current Sheet in Large Solar Energetic Particle Events
Moon, Yong-Jae; Jeong, Hyun-Jin; Park, Jinhye +1 more
The Fe/O enhancements exhibit significant variations in gradual solar energetic particle (SEP) events. Several causes have been suggested including transport effects in the interplanetary space and flare contribution. In this study, we investigate the relationship between the integrated Fe/O ratios of 27 gradual SEP events, locations of associated…
DIISC-IV. DIISCovery of Anomalously Low Metallicity H II Regions in NGC 99: Indirect Evidence of Gas Inflows
Heckman, Timothy; Momjian, Emmanuel; Jansen, Rolf A. +6 more
As a part of the Deciphering the Interplay between the Interstellar medium, Stars, and the Circumgalactic medium (DIISC) survey, we investigate indirect evidence of gas inflow into the disk of the galaxy NGC 99. We combine optical spectra from the Binospec spectrograph on the MMT telescope with optical imaging data from the Vatican Advanced Techno…
The Redshift of GRB 190829A/SN 2019oyw: A Case Study of GRB-SN Evolution
Fruchter, Andrew S.; Izzo, Luca; Tanvir, Nial +7 more
The nearby long gamma-ray burst (GRB) 190829A was observed using the Hubble Space Telescope/Wide Field Camera 3/infrared grisms about four weeks to 500 days after the burst. We find the spectral features of its associated supernova, SN 2019oyw, are redshifted by several thousand km s‑1 compared to the redshift of the large spiral galaxy…
Possible Supercritical Accretion on the Ultraluminous X-Ray Source in the Metal-poor Galaxy I Zw 18
Yoneyama, Tomokage; Matsumoto, Hironori; Noda, Hirofumi +2 more
We present an analysis of X-ray observations of the ultraluminous X-ray source (ULX) in I Zw 18 based on archival data taken with Chandra, XMM-Newton, and Suzaku. This ULX is considered to be an intermediate-mass black hole candidate simply because it is in the lowest-metallicity environment among ULXs, where the formation of heavy black holes is …