Search Publications
Chandra Observations of NGC 7212: Large-scale Extended Hard X-Ray Emission
Elvis, Martin; Fabbiano, G.; Siemiginowska, A. +5 more
Recent observations of nearby Compton thick (CT) active galactic nuclei (AGNs) with Chandra have resolved hard (>3 keV) X-ray emission extending out from the central supermassive black hole to kiloparsec scales, challenging the long-held belief that the characteristic hard X-ray continuum and fluorescent Fe K lines originate in the inner ∼parse…
Efficient Methanol Production on the Dark Side of a Prestellar Core
Bizzocchi, Luca; Caselli, Paola; Rosolowsky, Erik +23 more
We present Atacama Large Millimeter/submillimeter Array maps of the starless molecular cloud core Ophiuchus/H-MM1 in the lines of deuterated ammonia (ortho- ${\mathrm{NH}}_{2}{\rm{D}}$ ), methanol ( ${\mathrm{CH}}_{3}\mathrm{OH}$ ), and sulfur monoxide (SO). The dense core is seen in ${\mathrm{NH}}_{2}{\rm{D}}$ emission, whereas the ${\mathrm{CH}}…
MOSEL: Strong [OIII] 5007 Å Emitting Galaxies at (3 < z < 4) from the ZFOURGE Survey
Papovich, Casey; Kacprzak, Glenn G.; Glazebrook, Karl +13 more
To understand how strong emission-line galaxies (SELGs) contribute to the overall growth of galaxies and star formation history of the universe, we target SELGs from the ZFOURGE imaging survey that have blended Hβ+[O III] rest-frame equivalent widths of >230 Å and 2.5 < ${z}_{\mathrm{phot}}$ < 4.0. Using Keck/MOSFIRE, we measure 49 redshi…
The Blue Compact Dwarf Galaxy VCC 848 Formed by Dwarf-Dwarf Merging: H I Gas, Star Formation, and Numerical Simulations
Gao, Yu; Rong, Yu; Hunter, Deidre A. +12 more
A clear link between a dwarf-dwarf merger event and enhanced star formation (SF) in the recent past was recently identified in the gas-dominated merger remnant VCC 848, offering by far the clearest view of a gas-rich late-stage dwarf-dwarf merger. We present a joint analysis of JVLA H I emission line mapping, optical imaging, and numerical simulat…
Bridging the Planet Radius Valley: Stellar Clustering as a Key Driver for Turning Sub-Neptunes into Super-Earths
Kruijssen, J. M. Diederik; Longmore, Steven N.; Chevance, Mélanie
Extrasolar planets with sizes between that of the Earth and Neptune (Rp = 1-4 R⊕) have a bimodal radius distribution. This "planet radius valley" separates compact, rocky super-Earths (Rp = 1.0-1.8 R⊕) from larger sub-Neptunes (Rp = 1.8-3.5 R⊕) hosting a gaseous hydrogen-helium enve…
The Rise and Fall of the King: The Correlation between FO Aquarii's Low States and the White Dwarf's Spin-down
Walker, Gary; Garnavich, Peter; Littlefield, Colin +46 more
The intermediate polar FO Aquarii (FO Aqr) experienced its first reported low-accretion states in 2016, 2017, and 2018, and, using newly available photographic plates, we identify prediscovery low states in 1965, 1966, and 1974. The primary focus of our analysis, however, is an extensive set of time-series photometry obtained between 2002 and 2018…
Tidal Interaction between the UX Tauri A/C Disk System Revealed by ALMA
Palau, Aina; Zapata, Luis A.; Rodríguez, Luis F. +5 more
We present sensitive and high angular-resolution (∼0"2-0"3) (sub)millimeter (230 and 345 GHz) continuum and CO(2-1)/CO(3-2) line archive observations of the disk star system in UX Tauri carried out with the Atacama Large Millimeter/Submillimeter Array. These observations reveal the gas and dusty disk surrounding the young star UX Tauri A with a la…
Gaia and Hubble Unveil the Kinematics of Stellar Populations in the Type II Globular Clusters ω Centauri and M22
Da Costa, G. S.; Milone, A. P.; Cordoni, G. +8 more
The origin of multiple stellar populations in globular clusters (GCs) is one of the greatest mysteries of modern stellar astrophysics. N-body simulations suggest that the present-day dynamics of GC stars can constrain the events that occurred at high redshift and led to the formation of multiple populations. Here, we combine multiband photometry f…
Exploiting Orbital Constraints from Optical Data to Detect Binary Gamma-Ray Pulsars
Clark, C. J.; Nieder, L.; Allen, B. +1 more
It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is i…
Dust Environment Model of the Interstellar Comet 2I/Borisov
Fulle, M.; Cremonese, G.; Lazzarin, M. +27 more
2I/Borisov is the first interstellar comet discovered on 2019 August 30, and it soon showed a coma and a dust tail. This study reports the results of images obtained at the Telescopio Nazionale Galileo telescope, on La Palma - Canary Islands, in 2019 November and December. The images have been obtained with the R filter in order to apply our dust …