Search Publications
Extreme X-Ray Reflection in the Nucleus of the Seyfert Galaxy NGC 5033
Stern, D.; Brandt, W. N.; Fabian, A. C. +7 more
NGC 5033 is an intriguing Seyfert galaxy because its subclassification may change with time, and because optical and submillimeter observations find that the massive black hole does not sit at the dynamical center of the galaxy, pointing to a past merger. We obtained a new optical spectrum of NGC 5033 using the 200″ Hale telescope at Palomar that …
Milliarcsecond X-Ray Astrometry to Resolve Inner Regions of AGN at z > 1 Using Gravitational Lensing
Barnacka, Anna; Spingola, Cristiana; Schwartz, Daniel
We report the localization of the X-ray emission from two strongly lensed AGN, CLASS B0712+472 (z = 1.34) and CLASS B1608+656 (z = 1.394). We obtain milliarcsecond X-ray astrometry by developing a novel method that combines parametric lens modeling with a Bayesian analysis. We spatially locate the X-ray sources in CLASS B0712+472 and CLASS B1608+6…
FAST Search for Circumstellar Atomic Hydrogen. I. The Young Planetary Nebula IC 4997
Zhang, Yong; Zhang, Chuan-Peng; Parker, Quentin A. +3 more
Using the Five-hundred-meter Aperture Spherical radio Telescope in Guizhou, China, we detect the 21 cm neutral atomic hydrogen absorption in the young planetary nebula IC 4997. The absorption arises from a shell that is also associated with Na I D lines. The H I shell has a mass of 1.46 × 10-2 M ⊙ and a dynamic age of 990 yr.…
Extreme Solar Flare-driven Short-wave Fadeout Observed by SuperDARN ZHO Radar
Wang, M.; Liu, J.; Lu, J. Y. +6 more
Based on the observations from the Super Dual Auroral Radar Network at the Zhongshan Station (-74.9 MLAT, 97.2 MLON) and GOES satellites X-ray sensor, we present the first statistical study of the dayside ionospheric short-wave fadeout (SWF) events on the Southern Hemispheric high latitude from the years 2010-2019 and provide a normal characterist…
Spectroscopic Diagnostics of the Mid-infrared Features of the Dark Globule DC 314.8-5.1 with the Spitzer Space Telescope
Stawarz, Ł.; Rocha, W. R. M.; Kosmaczewski, E. +2 more
We present an analysis of the mid-infrared spectra, obtained from the Spitzer Space Telescope, of the dark globule DC 314.8-5.1, which is at the onset of low-mass star formation. The target has a serendipitous association with a B-type field star that illuminates a reflection nebula in the cloud. We focus on the polycyclic aromatic hydrocarbon (PA…
TIC 5724661: A Long-period Binary with a Pulsating sdB Star and δ Scuti Variable
Rappaport, Saul A.; Jayaraman, Rahul; Bieryla, Allyson +8 more
Using TESS 20 s cadence data, we have discovered an unusual combination of pulsating stars in what we infer to be a binary system. The binary consists of a standard δ Scuti star with pulsations over the range 32-41 day-1; this is in a likely wide orbit with a hot subdwarf-B (sdB) star, which itself has a large-amplitude p-mode pulsation…
The NuSTAR, XMM-Newton, and Suzaku View of A3395 at the Intercluster Filament Interface
Wik, Daniel R.; Tombesi, Francesco; Akamatsu, Hiroki +4 more
Galaxy clusters are the largest virialized objects in the universe. Their merger dynamics and their interactions with the cosmic filaments that connect them are important for our understanding of the formation of large-scale structure. In addition, cosmic filaments are thought to possess the missing baryons in the universe. Studying the interactio…
Very Large Array Multiband Radio Imaging of the Triple AGN Candidate SDSS J0849+1114
Nyland, Kristina; Li, Zhiyuan; Hou, Meicun +3 more
Kiloparsec-scale triple active galactic nuclei (AGNs), potential precursors of gravitationally bound triple massive black holes (MBHs), are rarely seen objects and believed to play an important role in the evolution of MBHs and their host galaxies. In this work we present a multiband (3.0, 6.0, 10.0, and 15.0 GHz), high-resolution radio imaging of…
SOFIA/FORCAST Monitoring of the Dust Emission from R Aqr: Start of the Eclipse
Gorti, Uma; Whitelock, Patricia A.; Wagner, R. Mark +3 more
We present mid-infrared (mid-IR) spectra from our continued monitoring of R Aquarii, the nearest symbiotic Mira, using the Stratospheric Observatory for Infrared Astronomy (SOFIA). New photometric and spectroscipic data were obtained with the Faint Object infraRed CAmera for the SOFIA Telescope in 2018 and 2019 after the system had started its "ec…
Hubble Space Telescope Observations of Tadpole Galaxies Kiso3867, SBS0, SBS1, and UM461
Kotulla, Ralf; Rafelski, Marc; Elmegreen, Bruce G. +8 more
Tadpole galaxies are metal-poor dwarfs with typically one dominant star-forming region, giving them a head-tail structure when inclined. A metallicity drop in the head suggests that gas accretion with even lower metallicity stimulated the star formation. Here we present multiband Hubble Space Telescope WFC3 and Advanced Camera for Surveys images o…