Search Publications
Exploring Gravitationally Lensed z ≳ 6 X-Ray Active Galactic Nuclei Behind the RELICS Clusters
Bradač, Maruša; Strait, Victoria; Coe, Dan +5 more
Although observations of high-redshift quasars demonstrate that many supermassive black holes (BHs) reached large masses within one billion years after the Big Bang, the origin of the first BHs is still a mystery. A promising way to constrain the origin of the first BHs is to explore the average properties of z ≳ 6 BHs. However, typical BHs remain…
Faint Stars in a Faint Galaxy. II. The Low-mass Stellar Initial Mass Function of the Boötes I Ultrafaint Dwarf Spheroidal Galaxy
Wyse, Rosemary F. G.; Kozhurina-Platais, Vera; Platais, Imants +1 more
This paper presents improved constraints on the low-mass stellar initial mass function (IMF) of the Boötes I (Boo I) ultrafaint dwarf galaxy, based on our analysis of recent deep imaging from the Hubble Space Telescope. The identification of candidate stellar members of Boo I in the photometric catalog produced from these data was achieved using a…
Globular Cluster UVIT Legacy Survey (GlobULeS). III. Omega Centauri in Far-ultraviolet
Dalessandro, Emanuele; Rao, N. Kameswara; Hutchings, John +21 more
We present the first comprehensive study of the most massive globular cluster, Omega Centauri, in the far-ultraviolet (FUV), extending from the center to ~28% of the tidal radius using the Ultraviolet Imaging Telescope on board AstroSat. A comparison of the FUV-optical color-magnitude diagrams with available canonical models reveals that horizonta…
Magnetohydrodynamic Simulation of Multiple Coronal Mass Ejections: An Effect of "Pre-events"
Wood, Brian E.; Wu, Chin-Chun; Liou, Kan +1 more
Coronal mass ejections (CMEs) are a major source of solar wind disturbances that affect the space plasma and magnetic field environment along their propagation path. Accurate prediction of the arrival of a CME at Earth or any point in the heliosphere is still a daunting task. In this study we explore an often overlooked factor-the effects of "pre-…
Investigating the Observational Properties of Type Ib Supernova SN 2017iro
Kumar, Brajesh; Anupama, G. C.; Singh, Avinash +1 more
We report results of optical imaging and low-resolution spectroscopic monitoring of supernova (SN) 2017iro that occurred in the nearby (~31 Mpc) galaxy NGC 5480. The He I λ5876 feature present in the earliest spectrum (-7 days) classified it as a Type Ib SN. The follow-up observations span from -7 to +266 days with respect to the B-band maximum. W…
Galactic Winds across the Gas-rich Merger Sequence. II. Lyα Emission and Highly Ionized O VI and N V Outflows in Ultraluminous Infrared Galaxies
Tripp, Todd M.; Veilleux, Sylvain; Liu, Weizhe +3 more
This paper is the second in a series aimed at examining the gaseous environments of z ≤ 0.3 quasars and ultraluminous infrared galaxies (ULIRGs) as a function of AGN/host galaxy properties across the merger sequence. This second paper focuses on the Lyα emission and O VI 1032, 1038 and N V 1238, 1243 absorption features, tracers of highly ionized …
Down but Not Out: Properties of the Molecular Gas in the Stripped Virgo Cluster Early-type Galaxy NGC 4526
Meier, David S.; Davis, Timothy A.; Young, Lisa M. +2 more
We present Atacama Large Millimeter/submillimeter Array data on the 3 mm continuum emission, CO isotopologues (12CO, 13CO, and C18O), and high-density molecular tracers (HCN, HCO+, HNC, HNCO, CS, CN, and CH3OH) in NGC 4526. These data enable a detailed study of the physical properties of the m…
The Substructures in the Anticenter Region of the Milky Way
Zhao, G.; Chen, Y. Q.; Zhang, Z. +3 more
We investigated the observational properties of Triangulum-Andromeda (TriAnd), Monoceros Ring (MRi), and Anti-Center Stream (ACS) in the anticenter region using K giants, M giants, and RGB stars from LAMOST and SDSS survey. The Friends of Friends algorithm was applied to select member stars of these structures. We found a new spur of TriAnd at l ~…
Accretion and Extinction Variations in the Low-mass Pre-main-sequence Binary System WX Cha
Pál, András; Ábrahám, Péter; Kóspál, Ágnes +5 more
Light curves of young star systems show photometric variability due to different kinematic and physical processes. One of the main contributors to the photometric variability is the changing mass accretion rate, which regulates the interplay between the forming young star and the protoplanetary disk. We collected high-resolution spectroscopy in ei…
A Highway for Atmospheric Ion Escape from Earth during the Impact of an Interplanetary Coronal Mass Ejection
Zong, Qiugang; Xie, Lun; Zhang, Hui +9 more
A single satellite hardly measures the overall ion escape rate from a planet. Therefore, the question concerning the long-term atmospheric evolution of whether a planetary magnetic field protects its atmosphere or aggravates atmospheric loss remains unresolved. Here, combined data from multiple platforms including Cluster, DMSP, IMAGE, and Polar s…