Search Publications
Spatially Resolved Properties of Galaxies from CANDELS+MUSE: Radial Extinction Profile and Insights on Quenching
Mobasher, Bahram; Jafariyazani, Marziye; Hemmati, Shoubaneh +3 more
Studying the internal processes of individual galaxies at kilo-parsec scales is crucial in enhancing our understanding of galaxy formation and evolution processes. In this work, we investigate the distribution of star formation rate (SFR), specific SFR (sSFR), and dust attenuation across individual galaxies for a sample of 32 galaxies selected fro…
Elliptical Galaxy in the Making: The Dual Active Galactic Nuclei and Metal-enriched Halo of Mrk 273
Veilleux, Sylvain; Liu, Weizhe; Rupke, David S. N. +7 more
A systematic analysis of the X-ray emission from the nearby ultraluminous infrared galaxy Mrk 273 was carried out by combining new 200 ks Chandra data with archived 44 ks data. The active galactic nucleus (AGN) associated with the southwest nucleus is confirmed by the new data, and a secondary hard X-ray (4-8 keV) point source is detected, coincid…
Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations
Chen, X. H.; Wang, K.; Zhang, X. B. +2 more
We report the discovery of an EL CVn-type binary consisting of a low-mass, pre-helium white dwarf and the first detection of hybrid δ Sct-γ Dor pulsations in such binary systems. Based on the four years Kepler data, we determined comprehensive photometric solution of the eclipsing binary KIC 8113154. The light-curve modeling reveals that it is a d…
Using Multiwavelength Variability to Explore the Connection among X-Ray Emission, the Far-ultraviolet H2 Bump, and Accretion in T Tauri Stars
Reynolds, M.; Grant, S.; Espaillat, C. C. +1 more
The high-energy radiation fields of T Tauri stars (TTS) should affect the surrounding circumstellar disk, having implications for disk transport and heating. Yet observational evidence of the effect of high-energy fields on disks is scarce. Here we investigate the connection between X-ray emission and the innermost gas disk by leveraging the varia…
Coronal Plasma Characterization via Coordinated Infrared and Extreme Ultraviolet Observations of a Total Solar Eclipse
Del Zanna, Giulio; DeLuca, Edward E.; Samra, Jenna E. +1 more
We present coordinated coronal observations of the 2017 August 21 total solar eclipse with the Extreme-ultraviolet Imaging Spectrometer (EIS) and the Airborne Infrared Spectrometer (AIR-Spec). These instruments provide an unprecedented view of the solar corona in two disparate wavelength regimes, the extreme ultraviolet (EUV) and the near- to mid-…
A Hard Look at NGC 5347: Revealing a Nearby Compton-thick AGN
Kaastra, J. S.; Stern, D.; Brandt, W. N. +11 more
Current measurements show that the observed fraction of Compton-thick (CT) active galactic nuclei (AGN) is smaller than the expected values needed to explain the cosmic X-ray background. Prior fits to the X-ray spectrum of the nearby Seyfert-2 galaxy NGC 5347 (z = 0.00792, D = 35.5 Mpc ) have alternately suggested a CT and Compton-thin source. Com…
A Dissection of Spatially Resolved AGN Feedback across the Electromagnetic Spectrum
Koss, Michael; Mushotzky, Richard; Crenshaw, D. Michael +7 more
We present optical SuperNova Integral Field Spectrograph integral field spectroscopy, Hubble Space Telescope optical imaging, Chandra X-ray imaging, and Very Large Array radio interferometry of the merging galaxy 2MASX J04234080+0408017, which hosts a Seyfert 2 active galactic nucleus (AGN) at z = 0.046. Our observations reveal that radiatively dr…
The Implications of Local Fluctuations in the Galactic Midplane for Dynamical Analysis in the Gaia Era
Hogg, David W.; Laporte, Chervin F. P.; Ness, Melissa K. +6 more
Orbital properties of stars, computed from their six-dimensional phase-space measurements and an assumed Galactic potential, are used to understand the structure and evolution of the Galaxy. Stellar actions, computed from orbits, have the attractive quality of being invariant under certain assumptions and are therefore used as quantitative labels …
3.8 µm Imaging of 400-600 K Brown Dwarfs and Orbital Constraints for WISEP J045853.90+643452.6AB
Apai, D.; Rieke, Marcia; Marley, Mark S. +10 more
Half of the energy emitted by late-T- and Y-type brown dwarfs emerges at 3.5 ≤ λ µm ≤ 5.5. We present new L‧ (3.43 ≤ λ µm ≤ 4.11) photometry obtained at the Gemini North telescope for nine late-T and Y dwarfs, and synthesize L‧ from spectra for an additional two dwarfs. The targets include two binary systems that were imaged at a resol…
Carbon and Oxygen Isotopic Ratios. II. Semiregular Variable M Giants
Pilachowski, Catherine A.; Lambert, David L.; Hinkle, Kenneth H. +3 more
Carbon and oxygen isotopic ratios are reported for a sample of 51 SRb- and Lb-type variable asymptotic giant branch stars. Vibration-rotation first- and second-overtone CO lines in 1.5-2.5 µm spectra were measured to derive isotopic ratios for 12C/13C, 16O/17O, and 16O/18O. Co…