Search Publications
FRagmentation and Evolution of Dense Cores Judged by ALMA (FREJA). I. Overview: Inner ∼1000 au Structures of Prestellar/Protostellar Cores in Taurus
Inutsuka, Shu-ichiro; André, Philippe; Tokuda, Kazuki +11 more
We have performed survey-type observations in 1 mm continuum and molecular lines toward dense cores (32 prestellar + 7 protostellar) with an average density of ≳105 cm-3 in the Taurus molecular clouds using the Atacama Large Millimeter/submillimeter Array-Atacama Compact Array (ALMA-ACA) stand-alone mode with an angular resol…
IRIS Observations of Short-term Variability in Moss Associated with Transient Hot Coronal Loops
Polito, Vanessa; Testa, Paola; De Pontieu, Bart
We observed rapid variability (≲60 s) at the footpoints of transient, hot (∼8-10 MK) coronal loops in active region cores, with the Interface Region Imaging Spectrograph (IRIS). The high spatial (∼0"33) and temporal (≲5-10 s) resolution of IRIS is often crucial for the detection of this variability. We show how, in combination with 1D RADYN loop m…
Constraining the Kilonova Rate with Zwicky Transient Facility Searches Independent of Gravitational Wave and Short Gamma-Ray Burst Triggers
Kulkarni, S. R.; Cenko, S. Bradley; Duev, Dmitry A. +34 more
The first binary neutron star merger, GW170817, was accompanied by a radioactivity-powered optical/infrared transient called a kilonova. To date, no compelling kilonova has been found in all-sky optical surveys, independently of short gamma-ray burst and gravitational-wave triggers. In this work, we searched the first 23 months of the Zwicky Trans…
LEGUS and Hα-LEGUS Observations of Star Clusters in NGC 4449: Improved Ages and the Fraction of Light in Clusters as a Function of Age
Grebel, Eva K.; Smith, Linda J.; Aloisi, Alessandra +17 more
We present a new catalog and results for the cluster system of the starburst galaxy NGC 4449, based on multiband imaging observations taken as part of the LEGUS and Hα-LEGUS surveys. We improve the spectral energy fitting method used to estimate cluster ages, and find that the results, particularly for older clusters, are in better agre…
Probing the Nature of High-redshift Weak Emission Line Quasars: A Young Quasar with a Starburst Host Galaxy
Neeleman, Marcel; Walter, Fabian; Simcoe, Robert A. +15 more
We present the discovery of PSO J083.8371+11.8482, a weak emission line quasar with extreme star formation rate at z = 6.3401. This quasar was selected from Pan-STARRS1, UHS, and unWISE photometric data. Gemini/GNIRS spectroscopy follow-up indicates a Mg II-based black hole mass of ${M}_{\mathrm{BH}}=\left({2.0}_{-0.4}^{+0.7}\right)\times {10}^{9}…
Retrieval of the d/sdL7+T7.5p Binary SDSS J1416+1348AB
Gonzales, Eileen C.; Marley, Mark S.; Faherty, Jacqueline K. +5 more
We present the distance-calibrated spectral energy distribution (SED) of the d/sdL7 SDSS J14162408+1348263A (J1416A) and an updated SED for SDSS J14162408+1348263B (J1416B). We also present the first retrieval analysis of J1416A using the Brewster retrieval code base and the second retrieval of J1416B. We find that the primary is best fit by a non…
Estimation of the Physical Parameters of a CME at High Coronal Heights Using Low-frequency Radio Observations
Vourlidas, Angelos; Mondal, Surajit; Oberoi, Divya
Measuring the physical parameters of coronal mass ejections (CMEs), particularly their entrained magnetic field, is crucial for understanding their physics and for assessing their geoeffectiveness. At the moment, only remote sensing techniques can probe these quantities in the corona, the region where CMEs form and acquire their defining character…
Dynamical Evidence of a Spiral Arm-driving Planet in the MWC 758 Protoplanetary Disk
Debes, John H.; Schneider, Glenn; Esposito, Thomas M. +22 more
More than a dozen young stars host spiral arms in their surrounding protoplanetary disks. The excitation mechanisms of such arms are under debate. The two leading hypotheses—companion-disk interaction and gravitational instability (GI)—predict distinct motion for spirals. By imaging the MWC 758 spiral arm system at two epochs spanning ∼5 yr using …
A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic Characterization of the Stellar Populations
Mastrobuono-Battisti, A.; Kacharov, N.; Böker, T. +9 more
The Sagittarius dwarf spheroidal galaxy is in an advanced stage of disruption but still hosts its nuclear star cluster (NSC), M54, at its center. In this paper, we present a detailed kinematic characterization of the three stellar populations present in M54: young metal-rich (YMR); intermediate-age metal-rich (IMR); and old metal-poor (OMP), based…
Modeling of the Variable Circumstellar Absorption Features of WD 1145+017
Xu, S.; Dufour, P.; Fortin-Archambault, M.
We present an eccentric precessing gas disk model designed to study the variable circumstellar absorption features detected for WD 1145+017, a metal polluted white dwarf with an actively disintegrating asteroid around it. This model, inspired by one recently proposed by Cauley et al., calculates explicitly the gas opacity for any predetermined phy…