Search Publications
A Morphological Study of Galaxies Hosting Optical Variability-selected AGNs in the COSMOS Field
Inoue, Akio K.; Yamada, Toru; Zhong, Yuxing +1 more
Morphological studies are crucial to investigate the connections between active galactic nucleus (AGN) activities and the evolution of galaxies. Substantial studies have found that radiative-mode AGNs primarily reside in disk galaxies, questioning the merger-driven mechanism of AGN activities. In this study, through Sérsic profile fitting and nonp…
Testing the Potential for Radio Variability in Disks around T Tauri Stars with Observations and Chemical Modeling
Calvet, N.; D'Alessio, P.; Macías, E. +5 more
A multiwavelength observing campaign of the T Tauri star (TTS) GM Aur was undertaken in 2019 December. This campaign obtained Swift X-ray and NUV fluxes, HST NUV spectra, LCOGT ${u}^{{\prime} }> ${g}^{{\prime} }> ${r}^{{\prime} }> ${i}^{{\prime} }> and TESS photometry, CHIRON Hα spectra, Atacama Large Millimeter/submillimeter Array (AL…
Topography of the Young Galactic Disk: Spatial and Kinematic Patterns of Clustered Star Formation in the Solar Neighborhood
González, Marta; Alfaro, Emilio J.; Sánchez-Gil, M. Carmen +3 more
The accuracy in determining the spatial-kinematical parameters of open clusters makes them ideal tracers of the Galactic structure. Young open clusters (YOCs) are the main representatives of the clustered star formation mode, which identifies how most of the stars in the Galaxy form. We apply the Kriging technique to a sample of Gaia YOCs within a…
Dissecting the Extended X-Ray Emission in the Merging Pair NGC 6240: Photoionization and Winds
Elvis, M.; Fabbiano, G.; Nardini, E. +3 more
We present a detailed spectral and imaging analysis of the central 15″ radius (~7.5 kpc) region of the merger galaxy NGC 6240 that makes use of all the available Chandra-ACIS data (0.3-3 keV effective exposure of ~190 ks). This region shows extended X-ray structures with lower-energy counterparts imaged in CO, [O III], and Hα line emission. We fin…
1RXH J082623.6-505741: A New Long-period Cataclysmic Variable with an Evolved Donor and a Low Mass-transfer Rate
Strader, Jay; Bahramian, Arash; Chomiuk, Laura +13 more
We report the discovery of 1RXH J082623.6-505741, a 10.4 hr orbital period compact binary. Modeling extensive optical photometry and spectroscopy reveals a ~0.4 M ⊙ K-type secondary transferring mass through a low-state accretion disk to a nonmagnetic ~0.8 M ⊙ white dwarf. The secondary is overluminous for its mass and domina…
The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z = 1 Cluster
Bianchi, S.; Macchetto, F. D.; Capetti, A. +10 more
3C 186, a radio-loud quasar at z = 1.0685, was previously reported to have both velocity and spatial offsets from its host galaxy, and has been considered as a promising candidate for a gravitational wave recoiling black hole triggered by a black hole merger. Another possible scenario is that 3C 186 is in an ongoing galaxy merger, exhibiting a tem…
The Origin of the Unfocused XMM-Newton Background, Its Variability, and Lessons Learned for ATHENA
Tiengo, Andrea; De Luca, Andrea; Marelli, Martino +7 more
We analyzed the unexposed to the sky (outFOV) region of the MOS2 detector on board XMM-Newton covering 15 yr of data amounting to 255 Ms. We show convincing evidence that the origin of the unfocused background in XMM-Newton is due to energetic protons, electrons, and hard X-ray photons. Galactic cosmic rays are the main contributors as shown by th…
Solar Polar Magnetic Fields: Comparing Full-disk and High-resolution Spectromagnetograph Data
Petrie, Gordon J. D.
This is the first systematic comparison between photospheric polar magnetic field data from a full-disk synoptic observing program, the National Solar Observatory's Synoptic Optical Long-term Investigations of the Sun Vector Spectromagnetograph (SOLIS/VSM), and a high-resolution vector spectromagnetograph, the Hinode Solar Optical Telescope Spectr…
Predicting the Geoeffectiveness of CMEs Using Machine Learning
Besliu-Ionescu, Diana; Paraschiv, Alin Razvan; Pricopi, Andreea-Clara +1 more
Coronal mass ejections (CMEs) are the most geoeffective space weather phenomena, being associated with large geomagnetic storms, and having the potential to cause disturbances to telecommunications, satellite network disruptions, and power grid damage and failures. Thus, considering these storms' potential effects on human activities, accurate for…
Ultraviolet Spectroscopy and TARDIS Models of the Broad-lined Type Ic Supernova 2014ad
Foley, Ryan J.; Modjaz, Maryam; Garnavich, Peter +11 more
Few published ultraviolet (UV) spectra exist for stripped-envelope supernovae and none to date for broad-lined Type Ic supernovae (SNe Ic-bl). These objects have extremely high ejecta velocities and are the only supernova type directly linked to gamma-ray bursts (GRBs). Here we present two epochs of HST/STIS spectra of the SN Ic-bl 2014ad, the fir…