Search Publications
ALMA and IRIS Observations of the Solar Chromosphere. II. Structure and Dynamics of Chromospheric Plages
Martínez-Sykora, Juan; De Pontieu, Bart; Chintzoglou, Georgios +7 more
We propose and employ a novel empirical method for determining chromospheric plage regions, which seems to better isolate a plage from its surrounding regions than other methods commonly used. We caution that isolating a plage from its immediate surroundings must be done with care in order to successfully mitigate statistical biases that, for inst…
Compton-Thick AGN in the NuSTAR ERA VII. A joint NuSTAR, Chandra, and XMM-Newton Analysis of Two Nearby, Heavily Obscured Sources
Vignali, C.; Gilli, R.; Ajello, M. +11 more
We present the joint Chandra, XMM-Newton, and NuSTAR analysis of two nearby Seyfert galaxies, NGC 3081 and ESO 565-G019. These are the only two having Chandra data in a larger sample of 10 low-redshift (z ≤ 0.05), candidates Compton-thick (CT) Active Galactic Nuclei selected in the 15-150 keV band with Swift-BAT that were still lacking NuSTAR data…
Beyond Simple AGN Unification with Chandra-observed 3CRR Sources at 0.5 < z < 1
Azadi, Mojegan; Wilkes, Belinda J.; McDowell, Jonathan C. +14 more
Low-frequency radio selection finds radio-bright galaxies regardless of the amount of obscuration by gas and dust. We report Chandra observations of a complete 178 MHz-selected, and so orientation-unbiased, sample of 44 0.5 < z < 1 3CRR sources. The sample is comprised of quasars and narrow-line radio galaxies (NLRGs) with similar radio lumi…
The VLA Frontier Field Survey: A Comparison of the Radio and UV/Optical Size of 0.3 ≲ z ≲ 3 Star-forming Galaxies
Smail, I.; Dickinson, M.; Jiménez-Andrade, E. F. +6 more
To investigate the growth history of galaxies, we measure the rest-frame radio, ultraviolet (UV), and optical sizes of 98 radio-selected, star-forming galaxies (SFGs) distributed over 0.3 ≲ z ≲ 3 with a median stellar mass of $\mathrm{log}({M}_{\star }/{M}_{\odot })\approx 10.4$ . We compare the size of galaxy stellar disks, traced by rest-frame o…
DR 21 South Filament: A Parsec-sized Dense Gas Accretion Flow onto the DR 21 Massive Young Cluster
Qiu, Keping; Li, Guangxing; Liu, Junhao +8 more
DR 21 south filament (DR21SF) is a unique component of the giant network of filamentary molecular clouds in the north region of the Cygnus X complex. Unlike the highly fragmented and star-forming active environment wherein it resides, DR21SF exhibits a coherent profile in the column density map with very few star formation signposts, even though t…
Gaia EDR3 Parallax Distances to the Great Carina Nebula and Its Star Clusters (Trumpler 14, 15, 16)
Shull, J. Michael; Danforth, Charles W.; Darling, Jeremy
Using offset-corrected Gaia EDR3 parallax measurements and spectrophotometric methods, we have determined distances for 69 massive stars in the Carina OB1 association and associated clusters: Trumpler 16 (21 stars), Trumpler 14 (20 stars), Trumpler 15 (three stars), Bochum 11 (five stars), and South Pillars region (20 stars). Past distance estimat…
Signature of a Heliotail Organized by the Solar Magnetic Field and the Role of Nonideal Processes in Modeled IBEX ENA Maps: A Comparison of the BU and Moscow MHD Models
Galli, A.; Richardson, J. D.; Zank, G. P. +9 more
Energetic neutral atom (ENA) models typically require post-processing routines to convert the distributions of plasma and H atoms into ENA maps. Here we investigate how two kinetic-MHD models of the heliosphere (the BU and Moscow models) manifest in modeled ENA maps using the same prescription and how they compare with Interstellar Boundary Explor…
A Low-mass Cold and Quiescent Core Population in a Massive Star Protocluster
Sanhueza, Patricio; Smith, Howard A.; Qiu, Keping +23 more
Pre-stellar cores represent the initial conditions of star formation. Although these initial conditions in nearby low-mass star-forming regions have been investigated in detail, such initial conditions remain vastly unexplored for massive star-forming regions. We report the detection of a cluster of low-mass starless and pre-stellar core candidate…
Impact of the Disk Thickness on X-Ray Reflection Spectroscopy Measurements
Tripathi, Ashutosh; Abdikamalov, Askar B.; Ayzenberg, Dimitry +2 more
In a previous paper, we presented an extension of our reflection model relxill_nk to include the finite thickness of the accretion disk following the prescription in Taylor & Reynolds. In this paper, we apply our model to fit the 2013 simultaneous observations by the Nuclear Spectroscopic Telescope Array (NuSTAR) and XMM-Newton of the supermas…
Evidence of Rocky Planet Engulfment in the Wide Binary System HIP 71726/HIP 71737
Meléndez, Jorge; Yana Galarza, Jhon; Lorenzo-Oliveira, Diego +1 more
Binary stars are supposed to be chemically homogeneous, as they are born from the same molecular cloud. However, high-precision chemical abundances show that some binary systems display chemical differences between the components, which could be due to planet engulfment. In this work, we determine precise fundamental parameters and chemical abunda…